Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2024 Nov 30;13(1):113.
doi: 10.1186/s13741-024-00471-y.

Preoperative cognitive training for the prevention of postoperative delirium and cognitive dysfunction: a systematic review and meta-analysis

Ka To Lau  1 , Lok Ching Sandra Chiu  2 , Janet Shuk Yan Fong  3 , Albert Kam Ming Chan  4 , Kwok Ming Ho  2 , Anna Lee  5
Affiliations
Review

Preoperative cognitive training for the prevention of postoperative delirium and cognitive dysfunction: a systematic review and meta-analysis

Ka To Lau et al. Perioper Med (Lond). .

Abstract

Background: Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are associated with major morbidity and mortality after surgery. This systematic review and meta-analysis determined whether preoperative cognitive training could reduce POD and POCD in patients undergoing elective surgery.

Methods: Eligible randomized controlled trials were identified from CENTRAL, MEDLINE, EMBASE, Scopus, Web of Science, and CINAHL databases from inception to April 30, 2024. Two independent reviewers extracted data on trial characteristics and risk of bias for each trial. We rated the quality of reporting of cognitive training interventions using the template for intervention description and replication (TIDieR) and evaluated the overall certainty (quality) of evidence using The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Random-effects models were used to summarize the treatment effect of cognitive training. Post hoc trial sequential analyses (TSA) were performed for POD and POCD to differentiate between "no evidence of effect" and "evidence of no effect."

Results: Seven trials (four high risk and three unclear risk of bias) involving 864 participants (mean or median age between 66 and 73 years old) were considered eligible and subject to meta-analysis. The quality of reporting cognitive training interventions was fair to moderate. Most cognitive prehabilitation programs were home-based, unsupervised, computerized interventions requiring 2.3-10 h over 1-4 weeks before surgery. Cognitive prehabilitation did not reduce POD (risk ratio [RR] 0.82, 95% confidence interval [CI] 0.57-1.18; I2 = 30%; low certainty of evidence in five trials) or early POCD after surgery (RR 0.93, 95% CI 0.58-1.49; I2 = 67%; very low certainty of evidence in four trials) compared to usual care. Nonetheless, TSA suggested that the sample sizes were insufficient to exclude the effectiveness of preoperative cognitive training in reducing POD or POCD. The participants' compliance rate was either not reported or mostly below 70%.

Conclusions: Current evidence is insufficient to determine the beneficial effect of preoperative cognitive training on POD or POCD. Given the well-established benefits of long-term cognitive training on cognition in the elderly, the design of future cognitive prehabilitation trials should be adequately powered and incorporated with strategies to improve patient compliance.

Keywords: Cognitive dysfunction; Cognitive rehabilitation; Confusion; Delayed neurocognitive recovery; Delirium; Neurocognitive disorders; Neuropsychological tests; Postoperative cognitive complications; Preoperative care.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: All authors, except the last and corresponding author, declare that they have no conflict of interest. AL is a content editor for both Cochrane Anaesthesia and Cochrane Emergency and Critical Care Review Groups, and a member on the Perioperative Medicine Editorial Board.

Figures

Fig. 1
Fig. 1
PRISMA flow diagram
Fig. 2
Fig. 2
Risk of bias items for each trial
Fig. 3
Fig. 3
Forest plot of the effect of preoperative cognition training on the risk of postoperative delirium
Fig. 4
Fig. 4
Forest plot of the effect of preoperative cognitive training on risk of early postoperative cognitive dysfunction
See this image and copyright information in PMC

References

    1. Borson S, Scanlan JM, Chen P, Ganguli M. The Mini-Cog as a screen for dementia: validation in a population-based sample. J Am Geriatr Soc. 2003;51(10):1451–4. - DOI - PubMed
    1. Breitbart W, Rosenfeld B, Roth A, Smith MJ, Cohen K, Passik S. The memorial delirium assessment scale. J Pain Symptom Manage. 1997;13(3):128–37. - DOI - PubMed
    1. Brown CH 4th, Laflam A, Max L, Lymar D, Neufeld KJ, Tian J, et al. The impact of delirium after cardiac surgical procedures on postoperative resource use. Ann Thorac Surg. 2016;101(5):1663–9. - DOI - PMC - PubMed
    1. Butz M, Meyer R, Gerriets T, Sammer G, Doerr JM, El-Shazly J, et al. Increasing preoperative cognitive reserve to prevent postoperative delirium and postoperative cognitive decline in cardiac surgical patients (INCORE): study protocol for a randomized clinical trial on cognitive training. Front Neurol. 2022;13: 1040733. - DOI - PMC - PubMed
    1. Chen CC, Li HC, Liang JT, Lai IR, Purnomo JDT, Yang YT, et al. Effect of a modified hospital elder life program on delirium and length of hospital stay in patients undergoing abdominal surgery: a cluster randomized clinical trial. JAMA Surg. 2017;152(9):827–34. - DOI - PMC - PubMed

LinkOut - more resources