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
. 2023;1(2):11.
doi: 10.1007/s44254-023-00006-6. Epub 2023 Apr 24.

Statistical fragility of reporting hemidiaphragmatic paralysis after brachial plexus blocks in randomized controlled trials: a systematic review

Quehua Luo #  1 , Yang Liu #  2 , Yi Zhu  1 , Zhipeng Wang  1 , Junyi Zheng  3 , Weifeng Yao  4
Affiliations
Review

Statistical fragility of reporting hemidiaphragmatic paralysis after brachial plexus blocks in randomized controlled trials: a systematic review

Quehua Luo et al. Anesthesiol Perioper Sci. 2023.

Abstract

To characterize the fragility index (FI) of statistically significant results reported in randomized controlled trials (RCTs) investigating the incidence of hemidiaphragmatic paralysis (HDP) after brachial plexus blocks. A systematic review of RCTs retrieved from the PubMed-Medline, Embase, and Web of Science electronic databases was conducted. All alternative RCTs published between January 2012 and October 2022 were identified. Only RCTs with two parallel arms designs, and reporting HDP as the primary outcome, statistical significance, and superiority results were selected. The FI was calculated according to Fisher's exact test using previously described methods. In addition, the risk of bias was evaluated using the Cochrane Risk-of-Bias tool for randomized trials. The 23 RCTs that fulfilled the inclusion criteria had a median FI of 4 (interquartile range [IQR]2-8) and a median Fragility Quotient of 0.077 (IQR 0.038- 0.129). However, in 13 (56.5%) trials, the calculated FI value was ≤ 4. In 3/23 (13.0%) trials, the number of patients who dropped-out exceeded the FI value. Most trials (91.3%) had an overall low risk of bias. This systematic review revealed that the statistical results of RCTs investing HDP after brachial plexus blocks have tended to be fragile in the past decade. The FI should be an important aid in the interpretation of clinical results in combination with the P-value, particularly when statistically significant results are dependent on a small number of events. Future RCTs with larger sample sizes are needed to obtain more robust results in this field.

Keywords: Brachial plexus block; Fragility index; Hemidiaphragmatic paralysis; Randomized controlled trials.

PubMed Disclaimer

Conflict of interest statement

Competing interestsThe authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Flowchart of the systematic search. RCTs, randomized controlled trials; HDP, hemidiaphragmatic paralysis
Fig. 2
Fig. 2
Distribution of FI, the number of patients Drop-out, and FI minus the number of patients Drop-out. When a trial’s P-value became non-significant without “converting” a patient from a non-event to an event, the FI is reported as “0”. FI, Fragility Index
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Tignanelli CJ, Napolitano LM. The Fragility Index in Randomized Clinical Trials as a Means of Optimizing Patient Care. JAMA Surg. 2019;154(1):74–9. 10.1001/jamasurg.2018.4318. - PubMed
    1. Wacholder S, Chanock S, Garcia-Closas M, El Ghormli L, Rothman N. Assessing the probability that a positive report is false: an approach for molecular epidemiology studies. J Natl Cancer Inst. 2004;96(6):434–42. 10.1093/jnci/djh075. - PMC - PubMed
    1. Walsh M, Srinathan SK, McAuley DF, Mrkobrada M, Levine O, Ribic C, et al. The statistical significance of randomized controlled trial results is frequently fragile: a case for a Fragility Index. J Clin Epidemiol. 2014;67(6):622–8. 10.1016/j.jclinepi.2013.10.019. - PubMed
    1. Feigl GC, Litz RJ, Marhofer P. Anatomy of the brachial plexus and its implications for daily clinical practice: regional anesthesia is applied anatomy. Reg Anesth Pain Med. 2020;45(8):620–7. 10.1136/rapm-2020-101435. - PubMed
    1. Cubillos J, Giron-Arango L, Munoz-Leyva F. Diaphragm-sparing brachial plexus blocks: a focused review of current evidence and their role during the COVID-19 pandemic. Curr Opin Anaesthesiol. 2020;33(5):685–91. 10.1097/ACO.0000000000000911. - PubMed

LinkOut - more resources