TY - JOUR
T1 - Why methods matter in a meta-analysis
T2 - a reappraisal showed inconclusive injury preventive effect of Nordic hamstring exercise
AU - Impellizzeri, Franco M.
AU - McCall, Alan
AU - van Smeden, Maarten
N1 - Funding Information:
We would like to thank the authors of previous original studies and meta-analysis that kindly provided us all the additional information and clarifications: Árni Árnason, John H.M. Brooks, Nick van der Horst, Rok Vatovec and Nejc Šarabon. We also thank Aaron J. Coutts for the comments provided regarding a preliminary version of this manuscript. Financial support: none. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Publisher Copyright:
© 2021
PY - 2021/12
Y1 - 2021/12
N2 - Objectives: The Nordic hamstring exercise (NHE) has been strongly recommended to reduce hamstring injuries in previous meta-analyses (50% reduction in risk of injury). To underline the importance and impact of adopting appropriate methodology for evidence synthesis, we revisited the study selection, reanalyzed and updated the findings of the most recent meta-analysis. Study Design and Setting: Only randomized control trials (RCT) using NHE as one of the prevention arms were selected. Summary effects for risk ratios (RR) for original studies included in the earlier meta-analysis, and new studies identified (update), were re-estimated under the random-effects model and presented with 95% confidence intervals (CI) and prediction intervals (PI). Tentative recommendations were provided according to the Grading of Recommendations Assessment, Development and Evaluation. Results: Only five RCTs out of the 15 studies included in the earlier meta-analysis randomized to NHE. Our update revealed one additional RCT. The point estimate (RR) for the five RCTs previously considered RCTs was 0.56 (95% CI, 0.20–1.52; 95% PI, 0.06–5.14, parametric, and 0.13–1.80, nonparametric). After the update, the RR was 0.59 (95% CI, 0.27–1.29; 95% PI 0.10–3.29, parametric, and 0.17–1.52, nonparametric). Conclusion: Contrary to the conclusions of a recent meta-analysis, as well as earlier meta-analyses, by using more appropriate methodology, the evidence underpinning the protective effect of NHE so far remains inconclusive and mostly derived from high risk of bias RCTs. At best, only conditional recommendation can be provided (for soccer) and future RCTs are warranted.
AB - Objectives: The Nordic hamstring exercise (NHE) has been strongly recommended to reduce hamstring injuries in previous meta-analyses (50% reduction in risk of injury). To underline the importance and impact of adopting appropriate methodology for evidence synthesis, we revisited the study selection, reanalyzed and updated the findings of the most recent meta-analysis. Study Design and Setting: Only randomized control trials (RCT) using NHE as one of the prevention arms were selected. Summary effects for risk ratios (RR) for original studies included in the earlier meta-analysis, and new studies identified (update), were re-estimated under the random-effects model and presented with 95% confidence intervals (CI) and prediction intervals (PI). Tentative recommendations were provided according to the Grading of Recommendations Assessment, Development and Evaluation. Results: Only five RCTs out of the 15 studies included in the earlier meta-analysis randomized to NHE. Our update revealed one additional RCT. The point estimate (RR) for the five RCTs previously considered RCTs was 0.56 (95% CI, 0.20–1.52; 95% PI, 0.06–5.14, parametric, and 0.13–1.80, nonparametric). After the update, the RR was 0.59 (95% CI, 0.27–1.29; 95% PI 0.10–3.29, parametric, and 0.17–1.52, nonparametric). Conclusion: Contrary to the conclusions of a recent meta-analysis, as well as earlier meta-analyses, by using more appropriate methodology, the evidence underpinning the protective effect of NHE so far remains inconclusive and mostly derived from high risk of bias RCTs. At best, only conditional recommendation can be provided (for soccer) and future RCTs are warranted.
KW - Bias
KW - Heterogeneity
KW - Injury
KW - Meta-analysis
KW - Prevention
KW - Research synthesis
KW - Sports medicine
UR - http://www.scopus.com/inward/record.url?scp=85116544226&partnerID=8YFLogxK
U2 - 10.1016/j.jclinepi.2021.09.007
DO - 10.1016/j.jclinepi.2021.09.007
M3 - Review article
C2 - 34520846
AN - SCOPUS:85116544226
SN - 0895-4356
VL - 140
SP - 111
EP - 124
JO - Journal of Clinical Epidemiology
JF - Journal of Clinical Epidemiology
ER -