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Review
. 2025 Oct 20;10(10):CD002042.
doi: 10.1002/14651858.CD002042.pub6.

Transfusion thresholds and other strategies for guiding red blood cell transfusion

Jeffrey L Carson  1 , Simon J Stanworth  2   3   4 , Jane A Dennis  5 , Dean A Fergusson  6 , Monica B Pagano  7 , Nareg H Roubinian  8 , Alexis F Turgeon  9   10 , Stacey Valentine  11 , Marialena Trivella  12 , Carolyn Dorée  4 , Paul C Hébert  13
Affiliations
Review

Transfusion thresholds and other strategies for guiding red blood cell transfusion

Jeffrey L Carson et al. Cochrane Database Syst Rev. .

Abstract

Background: The optimal haemoglobin threshold for use of red blood cell (RBC) transfusions in anaemic patients remains an active area of research. Blood is a limited resource, and there are concerns about risks, including transmitted infections. If a liberal transfusion strategy does not improve clinical outcomes, or if it is equivalent, then adopting a more restrictive approach should be recognised as the standard of care.

Objectives: The aim of this review update was to compare 30-day mortality and other clinical outcomes for participants randomised to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all clinical conditions. The restrictive transfusion threshold uses a lower haemoglobin concentration as a threshold for transfusion (most commonly, 7.0 g/dL to 8.0 g/dL), and the liberal transfusion threshold uses a higher haemoglobin concentration to direct transfusion (most commonly, 9.0 g/dL to 10.0 g/dL). Increasingly, investigators are considering other strategies including physiological triggers (i.e. central venous oxygen saturation), alone or in combination with such thresholds, to determine when a transfusion is indicated, so it is important to assess this growing body of evidence in tandem.

Search methods: We searched CENTRAL, MEDLINE, Embase, Transfusion Evidence Library, Web of Science Conference Proceedings Citation Index, trial registries and PubMed on 14 October 2024. We checked reference lists of published reviews and papers for additional trials.

Selection criteria: We included randomised trials of surgical or medical participants that recruited adults or children. We excluded studies that focused on preterm neonates. Eligible trials assigned intervention groups based on different transfusion strategies or thresholds, usually defined by a haemoglobin concentration below which a RBC transfusion would be administered. We included trials in which investigators had allocated participants to higher thresholds or more liberal transfusion strategies compared to more restrictive ones, which might include no transfusion.

Data collection and analysis: We used standard Cochrane methods. We pooled risk ratios across trials using a random-effects model. We assessed risk of bias using the Cochrane RoB 1 tool, and assessed the certainty of evidence using GRADE. We defined participants randomly allocated to the lower transfusion threshold as being in the 'restrictive transfusion' group and those randomly allocated to the higher transfusion threshold as being in the 'liberal transfusion' group.

Main results: Adult threshold comparison We included 61 trials (27,639 participants), across a range of clinical contexts: orthopaedic, cardiac or vascular surgery; critical care; neurocritical care; gastrointestinal bleeding; trauma; acute myocardial infarction; haematological malignancies and postpartum haemorrhage. The haemoglobin concentration used to define the restrictive transfusion group in most trials was between 7.0 g/dL and 8.0 g/dL. The main outcomes were exposure to blood transfusion, 30-day mortality, neurologic function, myocardial infarction, congestive heart failure, cerebral vascular accident, infection and thromboembolism. Studies were generally at low risk of bias. Restrictive transfusion strategies reduced the risk of receiving at least one RBC transfusion by 42% when combining all clinical contexts (risk ratio (RR) 0.58, 95% confidence interval (CI) 0.52 to 0.65; high-certainty evidence), with a large amount of heterogeneity between trials (I² = 97%), reflecting diversity in the strength of estimates, not the efficacy of the policy. When combining all clinical contexts, restrictive transfusion strategies did not modify the risk of 30-day mortality compared with liberal transfusion strategies (RR 1.01, 95% CI 0.90 to 1.14; 44 studies, 22,575 participants; high-certainty evidence) or any of the other outcomes assessed including myocardial infarction, stroke, thromboembolism or infection (moderate to high-certainty evidence). There were two exceptions in clinical populations. In gastrointestinal bleeding, 30-day mortality was lower with a restrictive transfusion strategy (RR 0.63, 95% CI 0.42 to 0.95; 4 studies, 1574 participants). In critically ill patients with brain injury, unfavourable neurological outcome at 6 to 12 months was lower with a liberal transfusion strategy (RR 1.14, 95% CI 1.05 to 1.22; 4 studies, 2297 participants) (moderate-certainty evidence). Transfusion-specific reactions are uncommon, but occurred more frequently with the liberal strategy (Peto odds ratio 0.47, 95% CI 0.36 to 0.62; 18 studies, 11,505 participants). Paediatric threshold comparison We included eight trials (2764 participants), across a limited range of clinical contexts (critical care, cardiac surgery, haematological malignancies and severe malarial anaemia). The haemoglobin concentration used to define the restrictive group in critical care and haematological malignancies trials was between 6.5 g/dL and 8.0 g/dL, and between 7.0 g/dL and 9 g/dL in cardiac surgery trials, depending on the cardiac abnormality and stage of repair. Studies were generally at low risk of bias. There was no clear difference in 30-day mortality between restrictive and liberal transfusion strategies, although confidence intervals were wide (RR 1.22, 95% CI 0.72 to 2.08; 7 studies, 2571 participants; low-certainty evidence). There was moderate-certainty evidence of no clear difference between threshold strategies for infection; very low-certainty evidence of little to no difference for thrombosis and very low-certainty evidence of little to no difference for the outcomes multiple organ dysfunction and cerebrovascular accident. Physiological triggers Nine trials in adults (3818 participants) and one trial in children (100 participants) were identified. These tested different interventions and measures of physiological parameters in diverse clinical populations. The risk of bias was variable. Meta-analysis was not appropriate due to heterogeneity.

Authors' conclusions: A restrictive transfusion strategy significantly decreased the proportion of adults and children exposed to RBC transfusion. In most clinical contexts, there was no evidence of harm from a restrictive compared with a liberal transfusion strategy. Neurocritically ill patients, however, have better neurological outcomes at 6 to 12 months with a liberal transfusion strategy. Further work is needed to improve our understanding of outcomes beyond mortality, and to what degree the optimal strategies for transfusion should be modified in some patient populations, including different types of acute bleeding, cancers and subgroups of patients with myocardial infarction and other neurological injuries. New studies need to recognise the clinical context and the limitations of the adoption of a single threshold of haemoglobin, and to consider evaluating the use of physiological parameters to modify transfusion.

Trial registration: ClinicalTrials.gov NCT01648946 NCT02099669 NCT00071032 NCT01167582 NCT02619136 NCT02981407 NCT04506125 NCT00350220 NCT00126334 NCT01502215 NCT02086773 NCT02648113 NCT02483351 NCT3309579 NCT00162617 NCT03407573 NCT02203292 NCT01102010 NCT01021631 NCT01485315 NCT00202371 NCT00651573 NCT00566709 NCT01484639 NCT02042898 NCT02465125 NCT00906295 NCT01079247 NCT00335023 NCT00470444 NCT01237639 NCT00414713 NCT00944112 NCT01116479 NCT01393496 ISRCTN89085577 NCT00318227 NCT03229941 NCT03369210 NCT03871244 NCT04754022.

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Conflict of interest statement

We have considered disclosures relevant to this review.

Jeffrey Carson reports being the chief investigator on four trials included in this review (Carson 1998; Carson 2011 (FOCUS); Carson 2013 (MINT pilot); Carson 2023a (MINT)). He has received multiple grants supporting his institution from the US National Institutes of Health. He has been involved with guideline development for red cell transfusions in the Association for the Advancement of Blood & Biotherapies (AABB). He has received travel expenses and an honorarium from Bristol Myer for attending a meeting and giving a lecture. He chaired a Data and Safety Monitoring Board (DSMB) for a trial sponsored by Cerus, for which he received travel expenses and an honorarium.

Carolyn Dorée: nothing to declare.

Dean Fergusson reports being an author on five completed trials included within this review (Hébert 1999 (TRICC); Mazer 2017 (TRICS III) (TRICS III); Shehata 2012; English 2024 (SAHaRA); Turgeon 2024 (HEMOTION)). He was a Co‐Principal Investigator on the TRICSIII trial (Mazer 2017 (TRICS III)); he was a member of the Steering Committee for the MINT trial (Carson 2023a (MINT)).

Paul Hébert reports being an author on four completed trials identified in this review (Hébert 1995 (TRICC pilot); Hébert 1999 (TRICC); Lacroix 2007 (TRIPICU); Carson 2023a (MINT)). He was the lead investigator on the study NCT02619136, the Canadian pilot study for MINT (Carson 2023a (MINT)) for which he was a member of the Executive Committee; he has published six non‐Cochrane reviews in this area. He serves on a guideline panel for the American College of Chest Physicians (ACCP) and has written several editorials for leading journals concerning transfusion triggers.

Nareg Roubinian: nothing to declare.

Simon Stanworth reports being an author on four included studies. He is the chief investigator on one (Stanworth 2020 (REDDS)); a co‐investigator on another (New 2025 (RePAST)) and a researcher and co‐author on two others (Gillies 2020 (RESULT‐NOF) and Morton 2022 (REAL pilot)); he is a co‐investigator on one ongoing study (Mo 2024) and contributes to another (POPTICCA; NCT03871244). He has received funding through institutions for RBC transfusion trials, including three in patients with haematological malignancy (with no direct funding). He has published four Cochrane and non‐Cochrane systematic reviews in this area, and is an Editor in a Cochrane thematic group; however, he has had no involvement in the editorial process for this review. He is a member of the AABB/International red cell transfusion guideline committee. He is employed by NHSBT, a national blood service, that collects blood for processing and issuing to hospitals. He is current Chair of the International Collaboration for Transfusion Medicine Guidelines (ICTMG).

Jane Dennis: membership of AABB/International RBC guideline committee.

Marialena Trivella: position of Statistical Editor in a Cochrane thematic group. MT has, however, had no involvement in the editorial process for this review.

Monica Pagano: membership of AABB RBC guideline committee. She has received travel expenses and an honorarium from the European Haematology Association (EHA) to attend their annual meeting.

Stacey Valentine ‐ membership of AABB RBC guideline committee.

Alexis Turgeon reports being an author on two included studies (as chief investigator on Turgeon 2024 (HEMOTION) and author on English 2024 (SAHaRA)). He is also the Director of Cochrane Canada Francophone; however, he has had no involvement in the editorial process for this review. He is the chair holder of the Canada Research Chair in Critical Care Neurology and Trauma.

All data extraction and decisions on risk of bias assessments were made by review authors not involved in the trials as researchers.

Update of

  • doi: 10.1002/14651858.CD002042.pub5

References

References to studies included in this review

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Bergamin 2017 (TRICOP) {published data only}
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Blair 1986 {published data only}
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    1. Buckstein R, Dennis J. "Cochrane review using your data from Buckstein et al 2024: some questions" (resulted in data on allocation concealment, mortality, thrombolic events and MIs). Email correspondence between Rena Buckstein, Jane Dennis and Simon Stanworth 2024 (7 to 9 May).
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    1. KCT0007596. A prospective, randomized, pilot study for optimal use of red cells in transfusion in patients with acute myeloid leukemia receiving dose intensive chemotherapy. https://cris.nih.go.kr./cris/search/detailSearch.do?seq=22595&search_page=L 2018 (reported as approved 21 August).
Carson 1998 {published data only}
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Carson 2011 (FOCUS) {published data only}
    1. Carson JL, Sieber F, Cook DR, Hoover DR, Noveck H, Chaitman BR, et al. Liberal versus restrictive blood transfusion strategy: 3-year survival and cause of death results from the FOCUS randomised controlled trial. Lancet 2015;385(9974):1183-9. [DOI: 10.1016/S0140-6736(14)62286-8] - DOI
    1. Carson JL, Terrin ML, Noveck H, Sanders DW, Chaitman BR, Rhoads GG, et al. Liberal or restrictive transfusion in high-risk patients after hip surgery. New England Journal of Medicine 2011;365(26):2453-62. [DOI: 10.1056/NEJMoa1012452] - DOI
    1. Gruber-Baldini AL, Marcantonio E, Orwig D, Magaziner J, Terrin M, Barr E, et al. Delirium outcomes in a randomized trial of blood transfusion thresholds in hospitalized older adults with hip fracture. Journal of the American Geriatrics Society 2013;61(8):1286-95. [DOI: 10.1111/jgs.12396] - DOI
Carson 2013 (MINT pilot) {published and unpublished data}
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Carson 2023a (MINT) {published and unpublished data}
    1. Carson J, Brooks MM, Chaitman B, Alexander J, Goodman S, Bertolet M et al. Rationale and design for the myocardial ischemia and transfusion (MINT) randomized clinical trial. American Heart Journal 2023;257:120-9. [DOI: 10.1016/j.ahj.2022.11.015] - DOI
    1. Carson JL, Brooks MM, Hébert PC, Goodman SG, Bertolet M, Glynn SA et al. Restrictive or liberal transfusion strategy in myocardial infarction and anemia. New England Journal of Medicine 2023;389:2446-56. [CLINICALTRIALS.GOV: NCT02619136] [CLINICALTRIALS.GOV: NCT02981407] [DOI: 10.1056/NEJMoa2307983] - DOI
    1. Carson JL, Dennis JA. Queries about MINT data prior to data entry in Cochrane review update (2024). Email correspondence between JL Carson and JA Dennis 2024 (13 to 19 February).
    1. NCT02619136. Myocardial ischemia and transfusion (MINT) [Myocardial ischemia and transfusion: a pilot, multi-centre, open-label randomized controlled trial of two commonly used transfusion strategies in patients with myocardial infarction]. www.clinicaltrials.gov/ct2/show/NCT02619136 (first posted 2 December 2015). [CTG: ]
    1. NCT02981407. Myocardial Ischemia and Transfusion (MINT). clinicaltrials.gov/ct2/show/NCT02981407 (first received 5 December 2016). [CTG: ]
Chapalain 2023 {published data only}
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    1. NCT04506125. Liberal versus restrictive transfusion threshold in oncologic surgery (LIBERTY1) [Liberal versus restrictive transfusion threshold in oncologic surgery: a multicenter, randomized, controlled, pilot study]. clinicaltrials.gov/ct2/show/NCT04506125 (first received 10 August 2020). [CTG: ]
Cholette 2011 {published and unpublished data}
    1. Cholette JM, Rubenstein JS, Alfleris GM, Powers KS, Eaton M, Lerner NB. Children with single-ventricle physiology do not benefit from higher hemoglobin levels post cavopulmonary connection: Results of a prospective, randomized, controlled trial of a restrictive versus liberal red-cell transfusion strategy. Pediatric Critical Care Medicine 2011;12(1):39-45. [CLINICALTRIALS.GOV: NCT00350220] [DOI: 10.1097/PCC.0b013e3181e329db] - DOI
Cholette 2017 {published data only}
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Cooper 2011 (CRIT) {published and unpublished data}
    1. Cooper HA, Rao SV, Greenberg MD, Rumsey MP, Mckenzie M, Alcorn KW, et al. Conservative versus liberal red cell transfusion in acute myocardial infarction (the CRIT randomized pilot study). American Journal of Cardiology 2011;108(8):1108-11. [DOI: 10.1016/j.amjcard.2011.06.014] - DOI
de Almeida 2015 {published data only}
    1. Almeida JP, Vincent JL, Galas FR, Almeida EP, Fukushima JT, Osawa EA, et al. Transfusion requirements in surgical oncology patients: a prospective, randomized controlled trial. Anesthesiology 2015;122(1):29-38. [DOI: 10.1097/ALN.0000000000000511] - DOI
de Gast Bakker 2013 {published data only}
    1. NL1608 (new number), NTR1691 (old number). Restrictive red blood cell policy in postoperative cardiac surgery patients. https://onderzoekmetmensen.nl/en/trial/24780 (last accessed 23 March 2025) (first received 1 March 2009).
    1. Gast-Bakker DH, Wilde RBP, Hazekamp MG, Sojak V, Zwaginga JJ, Wolterbeek R et al. Safety and effects of two red blood cell transfusion strategies in pediatric cardiac surgery patients: a randomized controlled trial. Intensive Care Medicine 2013;39:2011-19. [DOI: 10.1007/s00134-013-3085-7] - DOI
DeZern 2016 {published and unpublished data}
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Ducrocq 2021 (REALITY) {published data only}
    1. Ducrocq G, Gonzalez-Juanatey JR, Puymirat E, Lemesle G, Cachanado M, Durand-Zaleski I, et al. Effect of a restrictive vs liberal blood transfusion strategy on major cardiovascular events among patients with acute myocardial infarction and anemia: the REALITY randomized clinical trial. JAMA 2021;325(6):552-60. [DOI: 10.1001/jama.2021.0135] - DOI
    1. Durand-Zaleski I, Ducrocq G, Mimouni M, Frenkiel J, Avendano-Sola C, Gonzalez-Juanatey JR et al. Economic evaluation of restrictive vs. liberal transfusion strategy following acute myocardial infarction (REALITY): trial-based cost-effectiveness and cost-utility analyses. European Heart Journal 2023;9(2):194-202. [DOI: 10.1093/ehjqcco/qcac029] - DOI
    1. Gonzalez-Juanatey JR, Lemesle G, Puymirat E, Ducrocq G, Cachanado M, Arnaiz JA, et al, REALITY Investigators. One-year major cardiovascular events after restrictive versus liberal blood transfusion strategy in patients with acute myocardial infarction and anemia: the REALITY randomized trial. Circulation 2022;145(6):486-8. [DOI: 10.1161/CIRCULATIONAHA.121.057909] - DOI
English 2024 (SAHaRA) {published data only}
    1. English SW, Delaney A, Fergusson DA, Chassé M, Turgeon AF, Lauzier F, et al, SAHARA Trial Investigators on behalf of the Canadian Critical Care Trials Group. Liberal or restrictive transfusion strategy in aneurysmal subarachnoid hemorrhage. NEJM 2024 Dec 9 [Epub ahead of print]. [DOI: 10.1056/NEJMoa2410962] - DOI
    1. English SW, Fergusson D, Chassé M, Turgeon AF, Lauzier F, Griesdale D, et al, Canadian Critical Care Trials Group. Aneurysmal SubArachnoid Hemorrhage - Red Blood Cell Transfusion And Outcome (SAHaRA): a pilot randomised controlled trial protocol. BMJ Open 2016;6(12):e012623. [CTG: ] [DOI: 10.1136/bmjopen-2016-012623] - DOI
    1. NCT02483351. Aneurysmal subarachnoid hemorrhage: red blood cell transfusion and outcome (SAHaRA Pilot) [Aneurysmal subarachnoid hemorrhage: red blood cell transfusion and outcome - a pilot randomized controlled trial]. www.clinicaltrials.gov/ct2/show/NCT02483351 (first received 26 June 2015). [CTG: ]
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Fan 2014 {published data only}
    1. Fan YX, Liu FF, Jia M, Yang JJ, Shen JC, Zhu GM, et al. Comparison of restrictive and liberal transfusion strategy on postoperative delirium in aged patients following total hip replacement: a preliminary study. Archives of Gerontology and Geriatrics 2014;59(1):181-5. [DOI: 10.1016/j.archger.2014.03.009] - DOI
Fischer 2021 {published data only}
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Foss 2009 {published data only}
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Gillies 2020 (RESULT‐NOF) {published data only}
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Gobatto 2019 (TRAHT) {published data only}
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Gregersen 2015 (TRIFE) {published data only}
    1. Blandfort S, Gregersen M, Borris LC, Damsgaard EM. Blood transfusion strategy and risk of postoperative delirium in nursing homes residents with hip fracture. A post hoc analysis based on the TRIFE randomized controlled trial. Aging Clinical and Experimental Research 2017;29(3):459-66. [DOI: 10.1007/s40520-016-0587-5] - DOI
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Grover 2006 {published data only}
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Hajjar 2010 (TRACS) {published data only}
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Hayakawa 2023 (RESTRIC) {published data only}
    1. Hayakawa M, Tagami T, IIjima H, Kudo D, Sekine K, Ogura T, et al. Restrictive transfusion strategy for critically injured patients (RESTRIC) trial: a study protocol for a cluster-randomised, crossover non-inferiority trial. BMJ Open 2020 2020;10(9):e037238. [DOI: 10.1136/bmjopen-2020-037238] [UMIN000034405] - DOI
    1. Hayakawa M, Tagami T, Kudo D, Ono K, Aoki M, Endo A, et al. The Restrictive Red Blood Cell Transfusion Strategy for Critically Injured Patients (RESTRIC) trial: a cluster‑randomized, crossover, non‑inferiority multicenter trial of restrictive transfusion in trauma. Journal of Intensive Care 2023;11(34):1-14. [DOI: 10.1186/s40560-023-00682-3] - DOI
    1. UMIN000035992. Cluster randomized crossover non-inferiority trial by limiting blood transfusion for sever [sic] trauma patients. https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R0000... (first received 25 February 2019).
Hébert 1995 (TRICC pilot) {published data only}
    1. Hébert PC, Wells G, Marshall J, Martin C, Tweeddale M, Pagliarello G, et al. Transfusion requirements in critical care. A pilot study. Canadian Critical Care Trials Group [published erratum appears in JAMA 1995 Sep 27;274(12):944]. JAMA 1995;273(18):1439-44.
Hébert 1999 (TRICC) {published data only}
    1. Hébert PC, Wells G, Blajchman MA, Marshall J, Martin C, Pagliarello G, et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group. New England Journal of Medicine 1999;340(6):409-17. [DOI: 10.1056/NEJM199902113400601] - DOI
    1. McIntyre L, Hébert PC, Wells G, Fergusson D, Marshall J, Yetisir E, et al, Canadian Critical Care Trials Group. Is a restrictive transfusion strategy safe for resuscitated and critically ill trauma patients? Journal of Trauma 2004;57(3):563-8. [DOI: 10.1097/01.ta.0000136158.93864.54] - DOI
Hoff 2011 (DAHANCA) {published data only}
    1. Hoff CM, Hansen HS, Overgaard M, Grau C, Johansen J, Bentzen O, et al. The importance of haemoglobin level and effect of transfusion in HNSCC patients treated with radiotherapy - results from the randomized DAHANCA 5 study. Radiotherapy and Oncology 2011;1998:28-33. [DOI: 10.1016/j.radonc.2010.09.024] - DOI
    1. Hoff CM, Lassen P, Eriksen JG, Hansen HS, Specht L, Overgaard M, et al. Does transfusion improve the outcome for HNSCC patients treated with radiotherapy? Results from the randomized DAHANCA 5 and 7 trials. Acta Oncologica 2011;50(7):1006-14.
    1. Overgaard J, Hansen HS, Overgaard M, Bastholt L, Berthelsen A, Specht L, et al. A randomized double-blind phase III study of nimorazole as a hypoxic radiosensitizer of primary radiotherapy in supraglottic larynx and pharynx carcinoma: results of the Danish Head and Neck Cancer Study (DAHANCA) Protocol 5-85. Radiotherapy and Oncology 1998;46:135-46.
    1. Overgaard J, Hansen HS, Specht L, Overgaard M, Grau C, Anderson E, et al. Five compared with six fractions per week of conventional radiotherapy of squamous-cell carcinoma of head and neck: DAHANCA 6 & 7 randomised controlled trial. Lancet 2003;362:933-40.
Holst 2014 (TRISS) {published and unpublished data}
    1. Holst LB, Haase N, Wetterslev J, Wernerman J, Guttormsen AB, Karlsson S, et al. Lower versus higher hemoglobin threshold for transfusion in septic shock. New England Journal of Medicine 2014;371(15):1381-91. [DOI: 10.1056/NEJMoa1406617] - DOI
    1. Rygård SL, Holst LB, Wetterslev J, Winkel P, Johansson PI, Wernerman J, et al, TRISS Trial Group, Scandinavian Critical Care Trials Group. Long-term outcomes in patients with septic shock transfused at a lower versus a higher haemoglobin threshold: the TRISS randomised, multicentre clinical trial. Intensive Care Medicine 2016;42(11):1685-94. [DOI: 10.1007/s00134-016-4437-x] - DOI
Jairath 2015 (TRIGGER) {published data only}ISRCTN85757829
    1. Campbell HE, Stokes EA, Bargo D, Logan RF, Mora A, Hodge R, et al. Costs and quality of life associated with acute upper gastrointestinal bleeding in the UK: cohort analysis of patients in a cluster randomised trial. BMJ Open 2015;5(4):e007230. [DOI: 10.1136/bmjopen-2014-007230] - DOI
    1. Jairath V, Kahan BC, Gray A, Doré CJ, Mora A, James MW, et al. Restrictive versus liberal blood transfusion for acute upper gastrointestinal bleeding (TRIGGER): a pragmatic, open-label, cluster randomised feasibility trial. Lancet 2015;386(9989):137-44. [DOI: 10.1016/S0140-6736(14)61999-1] [ISRCTN: ISRCTN85757829] - DOI
    1. Kahan BC, Li F, Blette B, Jairath V, Copas A, Harhay M. Informative cluster size in cluster-randomised trials: a case study from the TRIGGER trial. Clinical Trials 2023;20(6):661-9. [DOI: 10.1177/17407745231186094]]
Jansen 2020 (TEMPLE) {published data only}
    1. Jansen AJG, den Bosch J, Te Boekhorst PAW, Schipperus MR, Beckers EAM. Results of the prematurely terminated TEMPLE randomized controlled trial in patients with myelodysplastic syndrome: liberal versus restrictive red blood cell transfusion threshold [Letter to the Editor]. Transfusion 2020;60(4):879-81. [CLINICALTRIALS.GOV: NCT00202371] [DOI: 10.1111/trf.15708] [ISRCTN: ISRCTN43616311] - DOI
Johnson 1992 {published data only}
    1. Johnson RG, Thurer RL, Kruskall MS, Sirois C, Gervino EV, Critchlow J, et al. Comparison of two transfusion strategies after elective operations for myocardial revascularization. Journal of Thoracic and Cardiovascular Surgery 1992;104(2):307-14. [DOI: 10.1016/S0022-5223(19)34782-8] - DOI
Koch 2017 {published and unpublished data}
    1. Koch CG, Sessler DI, Mascha EJ, Sabik JF 3rd, Li L, Duncan AI, et al. A randomized clinical trial of red blood cell transfusion triggers in cardiac surgery. Annals of Thoracic Surgery 2017;104(4):1243-50.
Kola 2020 {published data only}JIP/IEC/2015/615
    1. Kola G, Sureshkumar S, Mohsina S, Sreenath GS, Kate V. Restrictive versus liberal transfusion strategy in upper gastrointestinal bleeding: a randomized controlled trial. Saudi Journal of Gastroenterology 2020;27(1):13-9. [DOI: 10.4103/sjg.SJG_152_20] - DOI
Lacroix 2007 (TRIPICU) {published data only}
    1. Flatman LK, Fergusson DA, Lacroix J, Ducruet T, Papenburg J, Fontela PS. Association between leukoreduced red blood cell transfusions and hospital-acquired infections in critically ill children: a secondary analysis of the TRIPICU study. Vox Sanguinis 2022;117(4):545-52. [DOI: 10.1111/vox.13224] - DOI
    1. Karam O, Tucci M, Ducruet T, Hume HA, Lacroix J, Gauvin F, for the Canadian Critical Care Trials Group and the PALISI Network. Red blood cell transfusion thresholds in pediatric patients with sepsis. Pediatric Critical Care Medicine 2011;12(5):512-8. [DOI: 10.1097/PCC.0b013e3181fe344b] - DOI
    1. Lacroix J, Hébert PC, Hutchison JS, Hume HA, Tucci M, Ducruet T, et al. Transfusion strategies for patients in pediatric intensive care units. New England Journal of Medicine 2007;356(16):1609-19. [DOI: 10.1056/NEJMoa066240] - DOI
    1. Rouette J, Trottier H, Ducruet T, Beaunoyer, Lacroix J, Tucci M, for the Canadian Critical Care Trials Group and the PALISI Network. Red blood cell transfusion threshold in postsurgical pediatric intensive care patients. Annals of Surgery 2010;251(3):421-7. [DOI: 10.1097/SLA.0b013e3181c5dc2e] - DOI
    1. Willems A, Harrington K, Lacroix J, Biarent D, Joffe AR, Wensley D et al, on behalf of the TRIPICU investigators, for the Canadian Critical Care Trials Group, and the PALISI Network. Comparison of two red-cell transfusion strategies after pediatric cardiac surgery: a subgroup analysis. Pediatric Critical Care 2010;38(2):649-56. [DOI: 10.1097/CCM.0b013e3181bc816c] - DOI
Laine 2018 {published data only}
    1. Laine A, Niemi T, Schramko Al. Transfusion threshold of hemoglobin 80g/L is comparable to 100g/L in terms of bleeding in cardiac surgery: a prospective randomized study. Journal of Cardiothoracic and Vascular Anesthesia 2018;32(1):131-9. [DOI: 10.1053/j.jvca.2017.08.039] - DOI
Leal‐Noval 2017 {published data only}
    1. Leal-Noval SR, Arellano-Orden V, Maestre-Romero A, Muñoz-Gómez M, Fernández-Cisneros V, Ferrándiz-Millón C, et al. Red blood cell transfusion guided by near infrared spectroscopy in neurocritically ill patients with moderate or severe anemia: a randomized, controlled trial. Journal of Neurotrauma 2017;34(17):2553-9. [CLINICALTRIALS.GOV: NCT00566709] [DOI: 10.1089/neu.2016.4794] - DOI
Liao 2015 {published data only}
    1. Liao R, Sun H-R, Liu J, Huai S-M, Zheng J. Safety and effectiveness of reduced red blood cells consumption in spine surgery under the guidance of West China Perioperative Transfusion Score (WCPTS): a prospective, randomized, controlled trial. Journal of Anesthesia and Perioperative Medicine 2015;2:117-25. [CLINICALTRIALS.GOV: NCT01345643] [DOI: 10.24015/JAPM.2015.0017] - DOI
    1. NCT01345643. Clinical Trial of West-China Perioperative Transfusion Score (WCPTS) for massive hemorrhagic surgery (WCPTS). https://classic.clinicaltrials.gov/ct2/show/NCT01345643 (first received 2 May 2011).
Liao 2023 {published data only}NCT01597232
    1. Liao R, Liu J, Zhang W, Zheng H, Zhu Z, Sun H et al. Individualized red-cell transfusion strategy for non-cardiac surgery in adults: a randomized controlled trial. Chinese Medical Journal 2023;136(23):2857-66. [CLINICALTRIALS.GOV: NCT01597232] [DOI: 10.1097/CM9.0000000000002584] - DOI
    1. NCT01597232. Clinic Trial for West China Perioperative Transfusion Score (WCPTS). https://classic.clinicaltrials.gov/ct2/show/NCT01597232 (first received 11 May 2012).
Liu 2015 {published data only}
    1. CHiCTR-TRC-14004135. The effect and safety of the transfusion rating scheme scoring in emergency operation: a prospective, randomized, single-blind controlled clinical trial. https://www.chictr.org.cn/showproj.html?proj=5433 (first received 14 January 2014).
    1. Liu DX, Liu J, Zhang F, Zhang QY, Xie M, Zhu ZQ. Randomized controlled study on safety and feasibility of transfusion trigger score of emergency operations. Chinese Medical Journal 2015;128(13):1801-8. [DOI: 10.4103/0366-6999.159357] - DOI
Lotke 1999 {published data only}
    1. Lotke PA, Barth P, Garino JP, Cook EF. Predonated autologous blood transfusions after total knee arthroplasty: immediate versus delayed administration. Journal of Arthroplasty 1999;14(6):647-50. [DOI: 10.1016/s0883-5403(99)90216-4] - DOI
Lu 2022 {published data only}
    1. ChiCTR-INR-17014085. (POTTS) The individualized red cells transfusion strategy for the perioperative patients: a prospective randomized controlled multi-center clinical trial. http://www.chictr.org.cn/showproj.aspx?proj=18234 (first received 28 December 2017).
    1. Lu K, Huang Z, Liang S, Pan F, Zhang C, Wei J et al. Corrigendum. Transfusion Medicine 2023;33(1):98. [DOI: 10.1111/tme.12951] - DOI
    1. Lu K, Huang Z, Liang S, Pan F, Zhang C, Wei J, et al. A physiology-based trigger score to guide perioperative transfusion of allogeneic red blood cells: a multicentre randomised controlled trial. Transfusion Medicine 2022;32(5):375–82. [CHINESE CLINICAL TRIALS REGISTRY: ChiCTR-INR-17014085] [DOI: 10.1111/tme.12883] - DOI
Luo 2022 {published data only}
    1. ChiCTR-IPR-16007909. Clinical Trial of West-China Transfusion Score for Children (Safty [sic] and effectiveness of Pediatric Peri-Operative Transfusion Trigger Score: A Multi-Center, Randomized and Controled Research). http://www.chictr.org.cn/showproj.aspx?proj=13361 (first received 7 February 2016).
    1. Luo Z, Li Y, Li X, Liao R. An individualized red blood cell transfusion strategy using pediatric Perioperative-Transfusion-Trigger Score reduced perioperative blood exposure for children: a randomized controlled clinical trial. Therapeutics and Clinical Risk Management 2022;19:229–37. [CHINESE CLINICAL TRIALS REGISTER: ChiCTR-IPR-16007909] [DOI: 10.2147/TCRM.S388924] - DOI
Ma 2021 {published data only}
    1. ChiCTR1800016561. Clinical evaluation of appropriate technical standards for perioperative blood protection in patients with cardiovascular diseases. https://www.chictr.org.cn/showproj.html?proj=28145 (first received 8 June 2018).
    1. Ma HP, Zhang L, Chen CL, Li J, Ma ZT, Jiang QQ, et al. Evaluation of a novel cardiac Peri‑Operative Transfusion Trigger Scoring system in patients with coronary artery disease. BMC Cardiovascular Disorders 2021;21(40):1-11. [CHINESE CLINICAL TRIAL REGISTRY: chiCTR1800016561] [DOI: 10.1186/s12872-021-01854-5] - DOI
Maitland 2019 (TRACT) {published data only}
    1. Connon R, George EC, Olupot-Olupot P, Kiguli S, Chagaluka G, et al (group Tract trial). Incidence and predictors of hospital readmission in children presenting with severe anaemia in Uganda and Malawi: a secondary analysis of TRACT trial data. BMC Public Health 2021;21(1):1480. [DOI: 10.1186/s12889-021-11481-6] - DOI
    1. Maitland K, Kiguli S, Olupot-Olupot P, Opoka RO, Chimalizeni Y, Alaroker F, et al (group Tract Stakeholders meeting). Transfusion management of severe anaemia in African children: a consensus algorithm. British Journal of Haematology 2021;193(6):1247-59. [DOI: 10.1111/bjh.17429] - DOI
    1. Maitland K, Kiguli S, Olupot-Olupot, Engoru C, Mallewa M, Saramago Goncalves P, et al, the TRACT Group. Immediate transfusion in African children with uncomplicated severe anaemia. New England Journal of Medicine 2019;381(5):407-19. [DOI: 10.1056/NEJMoa1900105] [ISRCTN: ISRCTN84086586] - DOI
    1. Maitland K, Polupot-Olupot P, Kiguli S, Chagaluka G, Alaroker F, Opoka RO, et al, TRACT Group. Transfusion volume for children with severe anemia in Africa. New England Journal of Medicine 2019;381(5):420-31. [DOI: 10.1056/NEJMoa1900100] - DOI
    1. Uyoga S, Olupot-Olupot P, Connon R, Kiguli S, Opoka RO, Alaroker F et al. Sickle cell anaemia and severe Plasmodium falciparum malaria: a secondary analysis of the Transfusion and Treatment of African Children Trial (TRACT). The Lancet: Child & Adolescent Health 2022;6(9):606-13. [DOI: 10.1016/S2352-4642(22)00153-5] - DOI
Markatou 2012 {published data only}
    1. Markatou M, Theodoraki K, Rizos D, Fassoulaki A. Targeting perioperative hemoglobin in major abdominal surgery. Journal of Anesthesia & Clinical Research 2012;3(2):1-6. [DOI: 10.4172/2155-6148.1000190] - DOI
Mazer 2017 (TRICS III) {published data only}
    1. Galan J, Mateo E, Carmona P, Gajate L, Mazer CD, Martinez-Zapata MJ. Restrictive or liberal transfusion for cardiac surgery: Spanish TRICCS results of a randomized multicenter international parallel open-label clinical trial [Transfusión Restrictiva o liberal en cirugía cardiaca: Resultados españoles de un ensayo clínico aleatorizado, multicéntrico, internacional, paralelo y abierto]. Medicina Intensiva (English edition) 2020 Oct 1 [Epub ahead of print]. [DOI: 10.1016/j.medin.2020.07.011] - DOI
    1. Garg AX, Badner N, Bagshaw SM, Cuerden MS, Fergusson DA, Gregory AJ, et al, TRICS Investigators and Perioperative Anesthesia Clinical Trials Group. Safety of a restrictive versus liberal approach to red blood cell transfusion on the outcome of AKI in patients undergoing cardiac surgery: a randomized clinical trial. Journal of the American Society of Nephrology: JASN 2019;30(7):1294-304.
    1. Hu RT, Royse AG, Royse C, Scott DA, Bowyer A, Boggett S, et al. Health-related quality of life after restrictive versus liberal RBC transfusion for cardiac surgery: sub-study from a randomized clinical trial. Transfusion 2022;62(10):1973-83. [DOI: 10.1111/trf.17084] - DOI
    1. Mazer CD, Whitlock RP, Fergusson DA, Belley-Cote E, Connolly K, Khanykin B, et al, TRICS Investigators and Perioperative Anesthesia Clinical Trials Group. Restrictive or liberal red-cell transfusion for cardiac surgery. New England Journal of Medicine 2017;377(22):2133-44. [CLINICALTRIALS.GOV: NCT00202371 (pilot)] [CLINICALTRIALS.GOV: NCT02042898 (main)] [DOI: 10.1056/NEJMoa1711818] - DOI
    1. Mazer CD, Whitlock RP, Fergusson DA, Belley-Cote E, Connolly K, Khanykin B, TRICS Investigators and Perioperative Anesthesia Clinical Trials Group. Six-month outcomes after restrictive or liberal transfusion for cardiac surgery. New England Journal of Medicine 2018;379(13):1224-33.
Morton 2022 (REAL pilot) {published and unpublished data}ISRCTN96390716
    1. Dennis J, Stanworth S, Parsons J. Mortality in Morton. Email correspondence between Joseph Parsons and Simon Stanworth, and Simon Stanworth and Jane Dennis 2024 (9 to 17 May).
    1. Morton S, Sekhar M, Smethurst H, Mora A, Hodge RL, Hudson CL et al. Do liberal thresholds for red cell transfusion result in improved quality of life for patients undergoing intensive chemotherapy for acute myeloid leukemia? A randomized crossover feasibility study. Haematologica 2022;107(6):1474-8. [DOI: 10.3324/haematol.2021.279867] [ICTRP: ISRCTN 96390716] - DOI
    1. Morton S, Sekhar M, Smethurst H, Mora S, Hodge R, Hudson C, et al. Results for the REAL pilot randomised trial of red cell transfusion in acute myeloid leukaemia: is there sufficient evidence of equipoise to support a definitive study? British Journal of Haematology 2020;189 (Suppl 1):36-7. [ISRCTN: ISRCTN96390716]
Mullis 2023 (ORACL) {published data only}
    1. Mullis BH, Mullis LS, Kempton LB, Virkus W, Slaven JE, Bruggers J. Orthopaedic trauma and anemia: conservative versus liberal transfusion strategy: a prospective randomized study. Journal of Orthopedic Trauma 2023;38(1):18-28. [CLINICALTRIALS.GOV: NCT02972593] [DOI: 10.1097/BOT.0000000000002696] - DOI
    1. NCT02972593. ORthopaedic Trauma Anemia With Conservative Versus Liberal Transfusion (ORACL). https://classic.clinicaltrials.gov/ct2/show/NCT02972593 (first received 23 November 2016).
Murphy 2015 (TITRe2) {published data only}70923932
    1. Murphy GJ, Pike K, Rogers CA, Wordsworth S, Stokes EA, Angelini GD, et al. Liberal or restrictive transfusion after cardiac surgery. New England Journal of Medicine 2015;372:997-1008. [DOI: 10.1056/NEJMoa1403612] - DOI
    1. Stokes EA, Wordsworth S, Bargo D, Pike K, Rogers CA, Brierley RC, et al. Are lower levels of red blood cell transfusion more cost-effective than liberal levels after cardiac surgery? Findings from the TITRe2 randomised controlled trial. BMJ Open 2016;6(8):e011311. [DOI: 10.1136/bmjopen-2016-011311] - DOI
Møller 2019 {published data only}
    1. Møller A, Nielsen HB, Wetterslev J, Pedersen OB, Hellemann D, Winkel P, et al. Low vs high hemoglobin trigger for transfusion in vascular surgery: a randomized clinical feasibility trial. Blood 2019;133(25):2639-50. [DOI: 10.1182/blood-2018-10-877530] - DOI
    1. Møller A, Shahidi S, Wetterslev J, Helleman D, Pedersen OB, Marcussen KV, et al. Cardiac output in the transfusion triggers in vascular surgery trial. Acta Anaesthesiologica Scandinavica 2019;63:e12.
Naidech 2010 {published data only}
    1. Naidech AM, Shaibani A, Garg RK, Duran IM, Liebling SM, Bassin SL et al. Prospective, randomized trial of higher goal hemoglobin after subarachnoid hemorrhage. Neurocritical Care 2010;13(3):313-20. [DOI: 10.1007/s12028-010-9424-4] - DOI
New 2025 (RePAST) {unpublished data only}
    1. ISRCTN17438123. A small pilot feasibility study for a possible randomised control trial comparing clinical outcomes and quality of life following two different transfusion strategies in children undergoing allogeneic hematopoietic stem cell transplant (HSCT) [RePAST: Red cell transfusion in Paediatric Allogeneic HSCT - A feasibility randomised controlled trial comparing restrictive versus liberal red cell (RBC) transfusion strategies in children undergoing allogeneic haematopoietic stem cell transplant (HSCT)]. www.isrctn.com/ISRCTN17438123 (first received 23 May 2019). [ISRCTN: ISRCTN17438123]
    1. New HV, Sanderson E, Hopkins V, Thomas H, Gassas A, Adams M et al. How low can we go? Comparison of liberal and restrictive red cell transfusion thresholds in paediatric allogeneic haemopoetic stem cell transplantation: a randomised multicentre feasibility trial. British Journal of Haematology 2025 Apr 21 [Epub ahead of print]. [DOI: 10.1111/bjh.20051] - DOI
    1. Stanworth SJ, Dennis J. Re: Emily REPAST. Email correspondence between SJ Stanworth and J Dennis, J Dennis requested information from Emily Sanderson via Simon Stanworth re methods of sequence generation and allocation concealment 2025 (26 March).
Nielsen 2014 {published data only}
    1. Nielsen K, Johansson PI, Dahl B, Wagner M, Frausing B, Børglum J, et al. Perioperative transfusion threshold and ambulation after hip revision surgery - a randomized trial. BMC Anesthesiology 2014;14:89-98. [DOI: 10.1186/1471-2253-14-89] - DOI
Palmieri 2017 (TRIBE) {published data only}
    1. Palmieri TL, Holmes JH, Arnoldo B, Peck M, Cochran A, King BT, et al. Restrictive transfusion strategy is more effective in massive burns: results of the TRIBE multicenter prospective randomized trial. Military Medicine 2019;184 (Suppl 1):11-5. [DOI: 10.1093/milmed/usy279] - DOI
    1. Palmieri TL, Holmes JH, Arnoldo B, Peck M, Potenza B, Cochran A, et al. Transfusion requirement in burn care evaluation (TRIBE). A multicenter randomized prospective trial of blood transfusion in major burn injury. Annals of Surgery 2017;266:595-602. [DOI: 10.1097/SLA.0000000000002408] - DOI
    1. Sen S, Romanowski KS, Andre JA, Greenhalgh DG, Palmieri TL. Modified Frailty Index is an independent predictor of death in the burn population: a secondary analysis of the Transfusion Requirement in Burn Care Evaluation (TRIBE) study. Journal of Burn Care and Research 2023;44(2):257-61. [DOI: 10.1093/jbcr/irac164] - DOI
Parker 2013 {published data only}61328173
    1. Parker MJ. Randomised trial of blood transfusion versus a restrictive transfusion policy after hip fracture surgery. Injury 2013;44(12):1916-8. [DOI: 10.1016/j.injury.2013.04.033] - DOI
Prick 2014 (WOMB) {published data only}
    1. Prick BW, Duvekot JJ, Moer PE, Gemund N, Salm PC, Jansen AJ, et al. Cost-effectiveness of red blood cell transfusion vs. non-intervention in women with acute anaemia after postpartum haemorrhage. Vox Sanguinis 2014;107(4):381-8. [DOI: 10.1111/vox.12181] - DOI
    1. Prick BW, Jansen AJ, Steegers EA, Hop WC, Essink-Bot ML, Uyl-de Groot CA, et al. Transfusion policy after severe postpartum haemorrhage: a randomised non-inferiority trial. British Journal of Obstetrics and Gynaecology 2014;121(8):1005-14. [DOI: 10.1111/1471-0528.12531] - DOI
Robertson 2014 {published data only}
    1. Robertson CS, Hannay HJ, Yamal JM, Gopinath S, Goodman JC, Tilley BC, et al. Effect of erythropoietin and transfusion threshold on neurological recovery after traumatic brain injury: a randomized clinical trial. JAMA 2014;312(1):36-47.
Robitaille 2013 {published data only}
    1. Robitaille N, Lacroix J, Alexandrov L, Clayton L, Cortier M, Schultz KR, et al. Excess of veno-occlusive disease in a randomized trial on a higher trigger for red cell transfusion after bone marrow transplantation: a Canadian blood and marrow transplant group trial. Biology of Blood and Marrow Transplantation 2013;19:468-73. [DOI: 10.1016/j.bbmt.2012.12.002] - DOI
Salehi 2021 {published data only}
    1. IRCT20190209042660N1. A clinical trial on comparing morbidity and mortality of restrictive blood transfusion strategy with a traditional strategy in patients with a thermal burn. https://en.irct.ir/trial/43402 (first received 15 June 2020).
    1. Salehi SH, Daniali M, Motahi P, Momeni M. The best strategy for red blood cell transfusion in severe burn patients, restrictive or liberal: a randomized controlled trial. Burns 2020;47:1038-44. [DOI: 10.1016/j.burns.2020.06.038] - DOI
Shehata 2012 {published data only}
    1. Shehata N, Burns LA, Nathan H, Hebert P, Hare GM, Fergusson D, et al. A randomized controlled pilot study of adherence to transfusion strategies in cardiac surgery. Transfusion 2012;52(1):91-9. [DOI: 10.1111/j.1537-2995.2011.03236.x] - DOI
Slight 2008 {published data only}
    1. Slight RD, O’Donohoe P, Fung KY, Alonzi C, McClelland DBL, Mankad PS. Rationalizing blood transfusion in cardiac surgery: the impact of a red cell volume-based guideline on blood usage and clinical outcome. Vox Sanguinis 2008;95:205-10. [DOI: 10.1111/j.1423-0410.2008.01083.x] - DOI
So‐Osman 2013 {published data only}
    1. So-Osman C, Nelissen R, Brand R, Faber F, Slaa RT, Stiggelbout A, et al. The impact of a restrictive transfusion trigger on post-operative complication rate and well-being following elective orthopaedic surgery: a post-hoc analysis of a randomised study. Blood Transfusion (Transfusione del Sangue) 2013;11(2):289-95. [DOI: 10.2450/2013.0172-12] - DOI
    1. So-Osman C, Nelissen R, Te Slaa R, Coene L, Brand R, Brand A. A randomized comparison of transfusion triggers in elective orthopaedic surgery using leucocyte-depleted red blood cells. Vox Sanguinis 2010;98(1):56-64. [DOI: 10.1111/j.1423-0410.2009.01225.x] - DOI
    1. So-Osman C. A restrictive transfusion trigger is a method for blood saving in elective orthopaedic surgery. Vox Sanguinis 2004;87(Suppl 3):52.
Stanworth 2020 (REDDS) {published data only}26088319
    1. ISRCTN26088319. Red cell transfusion and QoL in myelodysplastic syndromes [Red blood cell transfusion thresholds and quality of life in myelodysplastic syndromes: a pilot, feasibility study]. www.isrctn.com/ISRCTN26088319 (first received 13 November 2014).
    1. Stanworth SJ, Killick S, McQuilten ZK, Karakantza M, Weinkove R, Smethurst H, et al, REDDS Investigators. Red cell transfusion in outpatients with myelodysplastic syndromes: a feasibility and exploratory randomised trial. British Journal of Haematology 2020;189(2):279-90. [DOI: 10.1111/bjh.16347] [ISRCTN26088319] - DOI
Taccone 2024 (TRAIN) {published data only}
    1. NCT02968654. TRansfusion Strategies in Acute Brain INjured Patients. https://classic.clinicaltrials.gov/ct2/show/NCT02968654 (first received 18 November 2016).
    1. Taccone FS, Badenes R, Rynkowski CB, Bouzat P, Caricato A, Kurtz P, et al. Correction: TRansfusion strategies in Acute brain INjured patients (TRAIN): a prospective multicenter randomized interventional trial protocol. Trials 2024;25(1):410. [DOI: 10.1186/s13063-024-08282-8] - DOI
    1. Taccone FS, Badenes R, Rynkowski CB, Bouzat P, Caricato A, Kurtz P, et al. TRansfusion strategies in Acute brain INjured patients (TRAIN): a prospective multicenter randomized interventional trial protocol. Trials 2023;24(1):20. [DOI: 10.1186/s13063-022-07061-7] - DOI
    1. Taccone FS, Rynkowski Bittencourt C, Møller K, Lormans P, Quintana-Diaz M, Caricato A et al. Restrictive vs liberal transfusion strategy in patients with acute brain injury: the TRAIN randomized clinical trial. JAMA 2024;332(19):1623-33. [DOI: 10.1001/jama.2024.20424] - DOI
Tay 2020 (TRIST) {published data only}
    1. Tay J, Allan DS, Chatelain E, Coyle D, Elemary M, Fulford A, et al. Liberal versus restrictive red blood cell transfusion thresholds in hematopoietic cell transplantation: a randomized, open label, phase III, noninferiority trial. Journal of Clinical Oncology 2020;38(13):1463-73. [DOI: 10.1200/JCO.19.01836] - DOI
Topley 1956 {published data only}
    1. Fisher MR, Topley ET. The illness of trauma. British Journal of Clinical Practice 1956;10(11):770-6. [PMID: ] - PubMed
Turgeon 2024 (HEMOTION) {published and unpublished data}
    1. NCT03260478. HEMOglobin Transfusion Threshold in Traumatic Brain Injury OptimizatioN: The HEMOTION Trial (HEMOTION). clinicaltrials.gov/ct2/show/NCT03260478 (first received 24 August 2017).
    1. Turgeon AF, Fergusson DA, Clayton L, Patton MP, Neveu X, Walsh TS, et al (HEMOTION Trial Investigators on behalf of the Canadian Critical Care Trials Group, the Canadian Perioperative Anesthesia Clinical Trials Group, and the Canadian Traumatic Brain Injury Research Consortium). Liberal or restrictive transfusion strategy in patients with traumatic brain injury. New England Journal of Medicine 2024 Jun 13 [Epub ahead of print]. [DOI: 10.1056/NEJMoa2404360] [PMID: ] - DOI - PubMed
    1. Turgeon AF, Fergusson DA, Clayton L, Patton MP, Zarychanski R, English S, et al, for the HEMOTION Trial Team, the Canadian Critical Care Trials Group, the Canadian Perioperative Anesthesia Clinical Trials Group and the Canadian Traumatic Brain Injury Research Consortium. Haemoglobin transfusion threshold in traumatic brain injury optimisation (HEMOTION): a multicentre, randomised, clinical trial protocol. BMJ Open 2023;12:e067117. [CLINICALTRIALS.GOV: NCT03260478] [DOI: 10.1136/bmjopen-2022-067117] - DOI
Villanueva 2013 {published and unpublished data}
    1. Colomo A, Hernandez-Gea V, Muniz-Diaz E, Madoz P, Aracil C, Alvarez-Urturi C. Transfusion strategies in patients with cirrhosis and acute gastrointestinal bleeding. Hepatology 2008;48(4 Suppl):413A.
    1. Villanueva C, Colomo A, Bosch A, Concepción M, Hernandez-Gea V, Aracil C, et al. Transfusion strategies for acute upper gastrointestinal bleeding. New England Journal of Medicine 2013;368(1):11-21. [DOI: 10.1056/NEJMoa1211801] - DOI
Villarejo 1999 {published data only}
    1. Villarejo F, Rizzolo M, Lópéz E, Domeniconi G, Arto G, Apezteguia C. Acute anemia in high digestive hemorrhage. Margins of security for their handling without transfusion of red globules [Anemia aguda en la hemorragia digestiva alta. Márgenes de suguridad para su manejo sin transfusiones de glóulos rojos]. Acta Gastroenterologica Latinoamericana 1999;29(4):261-70. [PMID: ] - PubMed
Walsh 2013 (RELIEVE) {published data only}
    1. Walsh TS, Boyd JA, Watson D, Hope D, Lewis S, Krishan A, et al. Restrictive versus liberal transfusion strategies for older mechanically ventilated critically ill patients: a randomized pilot trial. Critical Care Medicine 2013;41(10):2354-63. [DOI: 10.1097/CCM.0b013e318291cce4] - DOI
Webert 2008 {published and unpublished data}
    1. Webert KE, Cook RJ, Couban S, Carruthers J, Lee KA, Blajchman MA, et al. A multicenter pilot-randomized controlled trial of the feasibility of an augmented red blood cell transfusion strategy for patients treated with induction chemotherapy for acute leukemia or stem cell transplantation. Transfusion 2008;48(1):81-91. [DOI: 10.1111/j.1537-2995.2007.01485.x] - DOI
Yakymenko 2018 {published data only}
    1. Yakymenko D, Frandsen KB, Christensen IJ, Norgaard A, Johansson PI, Daugaard G, et al. Randomised feasibility study of a more liberal haemoglobin trigger for red blood cell transfusion compared to standard practice in anaemic cancer patients treated with chemotherapy. Transfusion Medicine 2018;28(3):208-15. [DOI: 10.1111/tme.12439] - DOI
Zeroual 2021 (ReTSEACS) {published data only}
    1. NCT02761564. SvO2 Trigger in Transfusion Strategy After Cardiac Surgery (ReTSEACS). https://clinicaltrials.gov/study/NCT02761564 (first received 4 May 2016).
    1. Zeroual N, Blin C, Saour M, David H, Aouinti S, Picot M-C et al. Restrictive transfusion strategy after cardiac surgery: role of central venous oxygen saturation trigger: a randomized controlled trial. Perioperative Medicine 2021;134(3):370-80. [CLINICALTRIALS.GOV: NCT02761564] [DOI: 10.1097/ALN.0000000000003682] - DOI

References to studies excluded from this review

ACTRN12606000167561 {unpublished data only}
    1. ACTRN12606000167561. A phase III feasibility study to evaluate the difference in average weekly haemoglobin concentrations between experimental and control groups and the impact of red cell concentrate transfusion of maintaining haemoglobin levels above 120g/l versus above 100g/l in anaemic patients with carcinoma of the cervix receiving concurrent cisplatin and radiation therapy. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=1260... (first received 1 May 2006).
Atilla 2017 {published data only}
    1. Atilla E, Toprak SK, Civriz Bozdag S, Topcuoglu P, Arslan O. A randomized comparison of hemoglobin content-based versus standard (unit-based) red blood cell transfusion policy. Turkish Journal of Haematology 2017;34(244):244-9.
Baron‐Stefaniak 2019 {published data only}
    1. Baron-Stefaniak J, Leitner GC, Kuntzel NKI, Meyer EL, Hiesmayr MJ, Ullrich R, et al. Transfusion of standard-issue packed red blood cells induces pulmonary vasoconstriction in critically ill patients after cardiac surgery - a randomized,double-blinded, clinical trial. PLOS One 2019;14(3):e0213000.
Bayliss 2021 {published data only}
    1. Bayliss CD, Maier R, Kasim A, Hancock H, Akowuah E. Does blood transfusion have an effect on outcomes after aortic valve replacement surgery? Heart, Lung & Circulation 2021;30(6):909-16.
Chantepie 2023 {published data only}
    1. Chantepie SP, Mear JB, Briant AR, Vilque JP, Gac AC, Cheze S, et al. Effect of single-unit transfusion in patients treated for haematological disease including acute leukemia: a multicenter randomized controlled clinical trial. Leukemia Research 2023;129:1-6. [CLINICALTRIALS.GOV: NCT02461264] [DOI: 10.1016/j.leukres.2023.107058] - DOI
    1. NCT02461264. Transfusion strategy in hematological intensive care unit (1VERSUS2CGR). https://classic.clinicaltrials.gov/ct2/show/NCT02461264 (first received 3 June 2015).
de Bruin 2019 {published data only}
    1. Bruin S, Scheeren TW, Bakker J, Bruggen R, Vlaar AP, Cardiovascular Dynamics Section and Transfusion Guideline Task Force of the ESICM. Cardiovascular Dynamics Section and Transfusion Guideline Task Force of the ESICM. Transfusion practice in the non-bleeding critically ill: an international online survey - the TRACE survey. Critical Care 2019;23:309. [DOI: 10.1186/s13054-019-2591-6] - DOI
Elshinawy 2020 {published data only}
    1. Elshinawy M, Al Marhoobi N, Al Abri R, Nazir HF, Khater D, Maktoom M, et al. Preoperative transfusion versus no transfusion policy in sickle cell disease patients: a randomized trial. Transfusion 2020;60(Suppl 1):S22-7.
Fogagnolo 2020 {published data only}
    1. Fogagnolo A, Taccone FS, Vincent JL, Benetto G, Cavalcante E, Marangoni E, et al. Using arterial-venous oxygen difference to guide red blood cell transfusion strategy. Critical Care 2020;24:160.
Fortune 1987 {published data only}
    1. Fortune JB, Feustel PJ, Saifi J, Stratton HH, Newell JC, Shah DM. Influence of hematocrit on cardiopulmonary function after acute hemorrhage. Journal of Trauma 1987;27(3):243-9.
Franz 2020 {published data only}
    1. Franz AR, Engel C, Bassler D, Rüdiger M, Thome UH, Maier RF, et al, the ETTNO Investigators. Effects of liberal vs restrictive transfusion thresholds on survival and neurocognitive outcomes in extremely low-birth-weight infants: the ETTNO randomized clinical trial. JAMA 2020;324:560-70. [CTG: ] [EUCTR: EUCTR2010-021576-28-DE]
Haensig 2019 {published data only}
    1. Haensig M, Kempfert J, Kempfert PM, Girdauskas E, Borger MA, Lehmann S. Thrombelastometry guided blood-component therapy after cardiac surgery: a randomized study. BMC Anesthesiology 2019;19(1):201. [DOI: 10.1186/s12871-019-0875-7] - DOI
Hamm 2020 {published data only}
    1. Hamm RF, Perelman S, Wang EY, Levine LD, Srinivas SK. 261: SMaRTBlood: randomized, controlled trial of Single- versus Multiple-unit Red cell Transfusion for non-acute postpartum anemia. In: American Journal of Obstetrics and Gynecology. Vol. 222 (Suppl 1). 2020:S179. [DOI: 10.1016/j.ajog.2019.11.277] - DOI
    1. Hamm RF, Perelman S, Wang EY, Levine LD, Srinivas SK. Single-unit vs multiple-unit transfusion in hemodynamically stable postpartum anemia: a pragmatic randomized controlled trial. American Journal of Obstetrics & Gynecology 2021;224(84):e1-84.e7. [CLINICALTRIALS.GOV: NCT03419780]
Ivkin 2023 {published data only}
    1. Ivkin AA, Grigoriev E, Sinitskaya AV. Refraining from packed red blood cells in cardiopulmonary bypass priming as a method of neuroprotection in pediatric cardiac surgery. Journal of Clinical Medicine 2023;12(4):1465 (article number).
Jain 2019 {published data only}
    1. Jain A, Raja A, Marwaha N, Trehan A. Comparison of efficacy of packed red blood cell transfusion based on its hemoglobin content versus the routine transfusion practice in thalassemia major patients. Vox Sanguinis 2019;114:213.
    1. Raja A, Jain A, Marwaha N, Trehan A. Comparison of efficacy of packed red blood cell transfusion based on its hemoglobin content versus the standard transfusion practice in thalassemia major patients (HEMOCON study). Transfusion and Apheresis Science 2020;59:6 (Article ID: 102736). [DOI: 10.1016/j.transci.2020.102736] - DOI
Kirpalani 2020 {published data only}
    1. Kirpalani H, Bell EF, Hintz SR, Tan S, Schmidt B, Chaudhary AS, et al. Higher or lower hemoglobin transfusion thresholds for preterm infants. New England Journal of Medicine 2020;383(27):2639-51.
Koster 2016 {published data only}
    1. Koster A, Zittermann A, Borgermann J, Knabbe C, Diekmann J, Schirmer U, et al. Transfusion of 1 and 2 units of red blood cells does not increase mortality and organ failure in patients undergoing isolated coronary artery bypass grafting. European Journal of Cardio-thoracic Surgery 2016;49:931-6.
Kumar 2019 {published data only}
    1. Kumar M, Ahmad J, Maiwall R, Choudhury A, Bajpai M, Mitra LG, et al. Thromboelastography-guided blood component use in patients with cirrhosis with nonvariceal bleeding: a randomized controlled trial. Hepatology 2019;71(1):235-46.
Mazza 2015 {published data only}
    1. Mazza BF, Freitas FGR, Barros MMO, Azevedo LCP, Machada FR. Blood transfusions in septic shock: is 7.0g/dL really the appropriate threshold? [Transfusões de sangue no choque séptico: 7,0g/dL é mesmo o limite adequado?]. Revista Brasileira de Terapia Intensiva 2015;27(1):37-46. [CLINICALTRIALS.GOV: NCT01611753] [DOI: 10.5935/0103-507X.20150007] - DOI
    1. NCT01611753. Red blood cell transfusion improves perfusion parameters in septic shock patients with hypoperfusion. https://classic.clinicaltrials.gov/ct2/show/NCT01611753 (first received 5 June 2012).
NCT01341002 {published and unpublished data}
    1. NCT01341002. Red blood cells (RBC) transfusion related to central venous O2 saturation (ScvO2) measurement. https://classic.clinicaltrials.gov/ct2/show/NCT01341002 (first received 25 April 2011).
    1. Vallet B, Dennis J. Re: Étude SAMU. Email correspondence between PI Benoit Vallet and Jane Dennis concerning the conduct/fate of NCT01341002 2024 (1 to 7 May).
NCT01402739 {published data only}
    1. NCT01402739. Algorithm-guided transfusions in cardiac surgery patients for reduction of drainage blood losses (HEART-PoC). https://classic.clinicaltrials.gov/ct2/show/NCT01402739 (first received 26 July 2011).
NCT01435746 {unpublished data only}
    1. NCT01435746. Transfusion Requirements After Orthotopic Liver Transplantation (TROLL). https://classic.clinicaltrials.gov/ct2/show/NCT01435746 (first received 16 September 2011).
NCT01452581 {unpublished data only}
    1. NCT01452581. Liberal versus restrictive transfusion during symptomatic moderate anemia after hip arthroplasty. https://classic.clinicaltrials.gov/ct2/show/NCT01452581 (first received 17 October 2011).
NCT02535208 {unpublished data only}
    1. NCT02535208. Combining restrictive guidelines and a NIRS SCORE to decrease RBC transfusions. https://classic.clinicaltrials.gov/ct2/show/NCT02535208 (first received 28 August 2015).
NCT03433508 {published data only}
    1. NCT03433508. Restrictive versus liberal red blood cell transfusion in patients of cirrhosis with septic shock. https://classic.clinicaltrials.gov/ct2/show/NCT03433508 (first received 14 February 2018).
NCT03643042 {published data only}
    1. NCT03643042. Impact of 2 transfusion strategies on quality of life of multitransfused patients with low-risk myelodysplastic syndrome (SMD-transfu). https://classic.clinicaltrials.gov/ct2/show/NCT03643042 (first received 22 August 2018).
Nielsen 2012 {published data only}
    1. NCT00967109. Establishment of optimal transfusion threshold during spine surgery. https://classic.clinicaltrials.gov/ct2/show/NCT00967109 (first received 27 August 2009).
    1. Nielsen K, Dahl B, Johansson PI, Hennberg SW, Rasmussen LS. Intraoperative transfusion threshold and tissue oxygenation: a randomised trial. Transfusion Medicine 2012;22:418-25. [CLINICALTRIALS.GOV: NCT00967109] [DOI: 10.1111/j.1365-3148.2012.01196.x] - DOI
NL Trial 45656 {published data only}
    1. NL Trial 45656. Preterm oxygenation of the cerebrum: key for erythrocyte-transfusion threshold. https://onderzoekmetmensen.nl/en/trial/45656 (first received 3 March 2017).
Olupot‐Olupot 2014 {published data only}
    1. Olupot-Olupot P, Engoru C, Thompson J, Nteziyareme J, Chebet M, Ssenyondo T, et al. Phase II trial of standard versus increased transfusion volume in Ugandan children with acute severe anemia. BMC Medicine 2014;12(67):1-11.
Osawa 2016 {published data only}
    1. Osawa EA, Rhodes A, Landoni G, Galas FR, Fukushima JT, Park CH, et al. Effect of perioperative goal-directed hemodynamic resuscitation therapy on outcomes following cardiac surgery: a randomized clinical trial and systematic review. Critical Care Medicine 2016;44(4):724-33. [DOI: 10.1097/CCM.0000000000001479] - DOI
Steffen 2023 {published data only}
    1. Steffen KM, Tucci M, Doctor A, Reeder R, Caro JJ, Muszynski JA, et al, Pediatric Critical Care Blood Research Network (BloodNet) subgroup of the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network. The impact of restrictive transfusion practices on hemodynamically stable critically ill children without heart disease: a secondary analysis of the age of blood in children in the PICU trial. Pediatric Critical Care Medicine 2023;24(2):84-92. [DOI: 10.1097/PCC.0000000000003128] - DOI
Vichinsky 1995 {published data only}
    1. Vichinsky EP, Haberkern CM, Neumayr L, Earles AN, Black D, Koshy M, et al. A comparison of conservative and aggressive transfusion regimens in the perioperative management of sickle cell disease. The Preoperative Transfusion in Sickle Cell Disease Study Group. New England Journal of Medicine 1995;333(4):206-13.
Voorn 2017 {published data only}
    1. Voorn VM, Marang-van de Mheen PJ, Hout A, Hofstede SN, So-Osman C, den Akker-van Marle ME, et al. The effectiveness of a de-implementation strategy to reduce low-value blood management techniques in primary hip and knee arthroplasty: a pragmatic cluster-randomized controlled trial. Implementation Science 2017;12(1):72. [DOI: 10.1186/s13012-017-0601-0] - DOI
Yamada 2020 {published data only}
    1. Yamada C, Takeshita A, Ohto H, Ishimaru K, Kawabata K, Nomaguchi Y, et al. A Japanese multi-institutional collaborative study of antigen-positive red blood cell (RBC) transfusions in patients with corresponding RBC antibodies. Vox Sanguinis 2020;115(5):456-65.
Zygun 2009 {published data only}
    1. Zygun DA, Nortje J, Hutchinson PJ, Timofeev I, Menon DK, Gupta AK. The effect of red blood cell transfusion on cerebral oxygenation and metabolism after severe traumatic brain injury. Critical Care Medicine 2009;37(3):1074-8.

References to studies awaiting assessment

ChiCTR2300071739 {published data only}
    1. ChiCTR2300071739. Effects of perioperative transfusion trigger score guided blood transfusion strategy on prognosis in elderly surgical patients: a multicenter, randomized controlled trial. https://www.chictr.org.cn/showproj.html?proj=197731 (first received 24 May 2023).
Chkhaidze 2014 {published data only}
    1. Chkhaidze M, Meterveli I, Tsintsadize A. Comparison of two RBC transfusion strategies in pediatric cardiac surgery patients. In: European Journal of Anaesthesiology. Vol. 20. 2014:94 (6AP2-94 (6A3)).
    1. Dennis JA. Comparison of two RBC transfusion strategies in pediatric cardiac surgery patients. Email to Jo Ann Hospital, Tbilisi 24 January 2023.
CTRI/2017/01/007726 {unpublished data only}
    1. CTRI/2017/01/007726. A clinical trial to compare lower(hemoglobin threshold for PRBC transfusion 7 gm/dl) vs higher hemoglobin threshold (hemoglobin threshold for PRBC transfusion 9 gm/dl) for transfusion in children with acute respiratory distress syndrome / A pilot randomized controlled trial comparing a lower versus higher hemoglobin threshold for transfusion in children with acute respiratory distress syndrome - TRICARDS. https://trialsearch.who.int/Trial2.aspx?TrialID=CTRI/2017/01/007726 (first received 9 November 2015).
    1. Muralidharan J, Dennis JA. Re: The TRICARDS study (CTRI/2017/01/007726). Personal correspondence 9 to 23 January 2023.
NCT00318227 {published data only}
    1. NCT00318227. Randomized trial of a liberal versus a restrictive transfusion strategy in elderly cardiac surgery patients. https://classic.clinicaltrials.gov/ct2/show/NCT00318227 (first received 26 April 2006).
Zhang 2020 {published data only}
    1. Zhang F, Zheng ZB, Zhu ZQ, Liu DX, Liu J. Application of perioperative transfusion trigger score in patients undergoing surgical treatment of malignant tumor. Indian Journal of Hematology and Blood Transfusion 2020;36(1):156-63. [CLINICALTRIALS.GOV: NCT01597232] [DOI: 10.1007/s12288-019-01180-z] - DOI

References to ongoing studies

ChiCTR2200057740 {unpublished data only}
    1. ChiCTR2200057740. A series of studies on central venous oxygen saturation as blood transfusion threshold in liver transplantation. https://www.chictr.org.cn/showproj.html?proj=162687 (first received 16 March 2022).
ChiCTR2200062976 {unpublished data only}
    1. ChiCTR2200062976. Effects of Perioperative Transfusion Trigger Score guided blood transfusion strategy on prognosis and cerebral oxygen metabolism and other mechanisms in elderly surgical patients. https://www.chictr.org.cn/showproj.html?proj=176857 (first received 25 August 2022).
ChiCTR2400083713 {unpublished data only}
    1. ChiCTR2400083713. Effect of different red blood cells transfusion strategies on the outcome of neurocritical patients: a randomized controlled study. https://www.chictr.org.cn/hvshowproject.html?id=251267&v=1.0 (first registered 30 April 2024).
ChiCTR2400088565 {unpublished data only}
    1. ChiCTR2400088565. The impact of strict and relaxed red blood cell infusion strategies on chemotherapy related serious adverse reactions in children with acute leukemia - a multicenter crossover design randomized controlled trial. https://www.chictr.org.cn/showproj.html?proj=239935 (first registered 21 August 2024):1.
ChiCTR‐INR‐16009434 {unpublished data only}
    1. ChiCTR-INR-16009434. The effect and safety of the transfusion rating scheme scoring in plateau patients with elective surgery operation: a prospective, randomized, single-blind controlled clinical trial. https://www.chictr.org.cn/showprojEN.html?proj=14796 (first received 15 October 2016).
ChiCTR‐IOR‐15007018 {unpublished data only}
    1. ChiCTR-IOR-15007018. Safety and feasibility of improved peri-operative transfusion trigger score for emergency hemorrhage patients randomized control trial. https://www.chictr.org.cn/showproj.html?proj=11818 (first received 5 September 2015).
ChiCTR‐TRC‐10000822 {unpublished data only}
    1. ChiCTR-TRC-10000822. Clinical research of restrictive transfusion in elderly patients undergoing orthopedic surgery. https://www.chictr.org.cn/showproj.html?proj=8714 (first received 4 January 2010).
ChiCTR‐TRC‐14004478 {unpublished data only}
    1. ChiCTR-TRC-14004478. A randomized-control multi-centres study on the safety & effectiveness of peri-operative transfusion trigger score (POTTS). https://www.chictr.org.cn/showprojEN.html?proj=5092 (first received 10 April 2014).
ISRCTN28818784; NIHR 130875 {unpublished data only}
    1. ISRCTN28818784. A randomised trial to investigate whether giving more blood transfusions to people undergoing surgery for hip fracture improves their outcomes. https://www.isrctn.com/ISRCTN28818784 (first registered 3 May 2022).
Kougias 2023 {published and unpublished data}
    1. Kougias P, Mi Z, Zhan M, Carson JL, Dosluoglu H, Nelson P, et al. Transfusion trigger after operations in high cardiac risk patients (TOP) trial protocol. Protocol for a multicenter randomized controlled transfusion strategy trial. Contemporary Clinical Trials 2023 Jan 20 [Epub ahead of print]. [DOI: 10.1016/j.cct.2023.107095] - DOI
    1. NCT03229941. Transfusion trigger after operations in high cardiac risk patients (TOP) [CSP #599 - Transfusion trigger after operations in high cardiac risk patients (TOP)]. clinicaltrials.gov/ct2/show/NCT03229941 (first received 26 July 2017). [CTG: ]
Meybohm 2019 {published and unpublished data}
    1. Meybohm P, Lindau S, Treskatsch S, Francis R, Spies C, Velten M, et al, LIBERAL Collaboration Group. Liberal transfusion strategy to prevent mortality and anaemia-associated, ischaemic events in elderly non-cardiac surgical patients - The study design of the LIBERAL-Trial. Trials 2019;20(1):101. [CTG: ] [DOI: 10.1186/s13063-019-3200-3] - DOI
    1. Schlesinger T, Studiengruppe Liberal. Liberal transfusion strategy for prevention of mortality and anemia-associated ischemic events in older noncardiac surgery patients-LIBERAL study [Liberale Transfusionsstrategie zur Prävention von Sterblichkeit und anämieassoziierten, ischämischen Ereignissen bei älteren, nicht-herzchirurgischen Patienten – LIBERAL-Studie]. Der Anaesthesist 2020;69(7):518-20. [DOI: 10.1007/s00101-020-00752-3] - DOI
Mo 2024 {published and unpublished data}
    1. ACTRN12619001053112. Red blood cell transfusion schedule in myelodysplastic syndromes: study 2 (REDDS-2) [A randomised feasibility n-of-1 trial of weekly-interval red cell transfusion myelodysplastic syndromes]. www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377401&isRe... (first received 4 June 2019). [ACTRN: ACTRN12619001053112]
    1. Mo A, Wood E, Shortt J, Charlton A, Evers D, Hoeks M et al. Rethinking the transfusion pathway in myelodysplastic syndromes: study protocol for a novel randomized feasibility n-of-1 trial of weekly-interval red cell transfusion in myelodysplastic syndromes: study protocol for a novel randomized feasibility n-of-1 trial of weekly-interval red cell transfusion in myelodysplastic syndromes. Transfusion 2024;64(2):236-47.
NCT01256645 {unpublished data only}
    1. NCT01256645. Transfusion strategies in weaning patients (WTT). https://classic.clinicaltrials.gov/ct2/show/record/NCT01256645 (first received 8 December 2010).
NCT01491308 {unpublished data only}
    1. NCT01491308. Restrictive versus liberal red cell transfusion strategy in orthopedic-oncology patients undergoing surgery - a randomized controlled study. https://classic.clinicaltrials.gov/ct2/show/NCT01491308 (first received 13 December 2013).
NCT02139995 {unpublished data only}
    1. NCT02139995. West-China Transfusion Score for critically-ill patients. https://classic.clinicaltrials.gov/ct2/show/NCT02139995 (first received 16 May 2014).
NCT02951013 {unpublished data only}
    1. NCT02951013. Transfusion strategies for pediatric liver transplantation. https://clinicaltrials.gov/study/NCT02951013 (first received 1 November 2016). [CLINICALTRIALS.GOV: NCT02951013] [LOCAL: PLT20161023]
NCT03837171 {unpublished data only}
    1. NCT03837171. TRANSfusion in Patients With Onco-hematological Malignancies ResusciTated From Septic Shock (TRANSPORT). https://classic.clinicaltrials.gov/ct2/show/NCT03837171 (first received 12 February 2019).
NCT03871244 {unpublished data only}
    1. NCT03871244. Pilot Optimizing Transfusion Thresholds in Critically-ill Children with Anaemia (P-OpTTICCA) [Pilot Optimizing Transfusion Thresholds in Critically-ill Children with Anaemia (P-OpTTICCA): a pilot trial for a large pragmatic international parallel open-label non-inferiority randomised controlled trial]. clinicaltrials.gov/ct2/show/NCT03871244 (first received 12 March 2019). [CTG: ]
    1. Tucci M, Du Pont-Thibodeau G, Leteurtre S, Sarfatti A, Ray S, Stanworth S, et al. A pilot randomized controlled trial to organize OpTTICCA, which will be a large international trial on the efficacy and safety of a low hemoglobin threshold to guide red blood cell transfusions in almost all anemic critically ill children. Annals of Intensive Care. Conference: French Intensive Care Society International Congress 2023;13:S1. [PMID: 10.1186/s13613-023-01131-y] - DOI
NCT04155489 {unpublished data only}
    1. NCT04155489. The impact of perioperative transfusion on postoperative cognitive dysfunction. https://classic.clinicaltrials.gov/ct2/show/NCT04155489 (first received 7 November 2019).
NCT04591574 {unpublished data only}
    1. NCT04591574. ABC - a post intensive care anaemia management trial [Anaemia management with red blood cell transfusion to improve post-intensive care disability: a randomised controlled trial (the ABC post-intensive care trial)]. https://clinicaltrials.gov/ct2/show/NCT04591574 (first received 19 October 2020).
NCT04754022 {unpublished data only}
    1. NCT04754022. Transfusion requirements in younger patients undergoing cardiac surgery (TRICS-IV) [An international, multi-centre, randomized controlled trial to assess transfusion thresholds in younger patients undergoing cardiac surgery]. www.clinicaltrials.gov/ct2/show/NCT04754022 (first received 15 February 2021). [CTG: ]
NCT04859855 {unpublished data only}
    1. NCT04859855. Transfusional trigger in post-operative oncologic patients in critical care. https://classic.clinicaltrials.gov/ct2/show/NCT04859855 (first received 26 April 2021).
NCT04920045 {unpublished data only}
    1. NCT04920045. A trial to assess the effect of transfusion strategies on fatigability levels after hospital discharge (EToF). https://classic.clinicaltrials.gov/ct2/show/NCT04920045 (first received 9 June 2021).
NCT05405426 {unpublished data only}
    1. NCT05405426. Trial of indication-based transfusion of red blood cells in ECMO (TITRE). https://classic.clinicaltrials.gov/ct2/show/NCT05405426 (first received 6 June 2022).
    1. Sleeper LA, Alexander P, Kelly DP, Bembea MM, Bellinger DC, Sadhwani A, et al. (1120) Chasing the dream (of equipoise): design and execution challenges of the multicenter TITRE trial of indication-based red blood cell transfusion in pediatric ECMO. Journal of Heart and Lung Transplantation/ISHLT 43rd Annual Meeting and Scientific Sessions 19–22 April 2023; Colorado Convention Center Denver, CO USA 2023;42(4 Suppl):S481. [DOI: 10.1016/j.healun.2023.02.1331] - DOI
    1. Sleeper LA, Alexander P, Kelly DP, Bembea MM, Bellinger DC, Sadhwani A, et al. Chasing the dream (of equipoise): design and execution challenges of the multicenter TITRE trial of indication-based red blood cell transfusion in pediatric ECMO. Perfusion 2023;38 (Suppl):20230527. [DOI: 10.1177/02676591231162023] - DOI
NCT05607940 {unpublished data only}
    1. NCT05607940. Effect of indication based blood product transfusion in patients undergoing major oncological surgery. https://clinicaltrials.gov/study/NCT05607940 (first received 7 November 2022).
NCT05699005 {unpublished data only}
    1. NCT05699005. Individualized or conventional transfusion strategies during peripheral VA-ECMO. https://clinicaltrials.gov/study/NCT05699005 (first received 26 January 2023).
NCT05740059 {unpublished data only}
    1. NCT05740059. Restrictive Transfusion StratEgy Adjusted by SvO2 During Cardiac Surgery (RETSEACSII). https://clinicaltrials.gov/study/NCT05740059 (first received 22 February 2023).
NCT05814094 {unpublished data only}
    1. NCT05814094. Red blood cell transfusion in ECMO - a feasibility trial (ROSETTA). https://clinicaltrials.gov/study/NCT05814094 (first received 14 April 2023).
NCT05841706 {unpublished data only}
    1. NCT05841706. Red blood cell transfusion thresholds for improved quality of life for patients undergoing a pancreatectomy for pancreatic cancer standard. https://clinicaltrials.gov/study/NCT05841706 (first received 3 May 2023).
NCT06102590 {unpublished data only}
    1. NCT06102590. Oxygen extraction-guided transfusion strategy in critically ill patients. A randomized controlled trial [Oxygen extraction-guided transfusion (OXYTRIP)]. https://clinicaltrials.gov/search?term=NCT06102590 (first received 26 October 2023).
NCT06332547 {unpublished data only}
    1. NCT06332547. A multicenter prospective, randomized controlled study of different transfusion thresholds in cardiac valve surgery. https://clinicaltrials.gov/study/NCT06332547 2024 (first received 27 March 2024).
NCT06526533 {unpublished data only}
    1. NCT06526533. Reducing major complications to improve the safety and efficacy of ECMO in severe cardiac and respiratory failure (RECOMMEND). https://clinicaltrials.gov/study/NCT06526533 (first received 30 July 2024).
NCT06560164 {unpublished data only}
    1. NCT06560164. Restrictive versus liberal thresholds for red blood cell transfusion in extracorporeal membrane oxygenation - the TREC study. https://clinicaltrials.gov/study/NCT06560164 (first received 19 August 2024).
NL‐OMON32131 {unpublished data only}
    1. NL-OMON32131. Effect of increasing low serum hemoglobin level on functional recovery after hip fracture surgery in the elderly. A prospective randomized clinical trial. https://onderzoekmetmensen.nl/en/trial/32131 (first received 7 July 2008).

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