The Impact of Study Size on Meta-analyses: Examination of Underpowered Studies in Cochrane Reviews

PLoS ONE

Volumn 8, Issue 3, 2013, Pages

  Turner, Rebecca M ^a   Bird, Sheila M ^a   Higgins, Julian P T ^b,c  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^b UNIVERSITY OF BRISTOL   (United Kingdom)

^c UNIVERSITY OF YORK   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ANALYTICAL ERROR; ARTICLE; COCHRANE LIBRARY; INFORMATION SYSTEM; META ANALYSIS (TOPIC); POWER ANALYSIS; RISK REDUCTION; SAMPLE SIZE; STUDY DESIGN;

HUMANS; META-ANALYSIS AS TOPIC; ODDS RATIO; REVIEW LITERATURE AS TOPIC; RISK REDUCTION BEHAVIOR; SAMPLE SIZE;

EID: 84875424429     PISSN: None     EISSN: 19326203     Source Type: Journal    
DOI: 10.1371/journal.pone.0059202     Document Type: Article

References (25)

1. Sterne JAC, Gavaghan D, Egger M, (2000) Publication and related bias in meta-analysis: power of statistical tests and prevalence in the literature. Journal of Clinical Epidemiology 53: 1119-29.
2. Nygard O, Vollset SE, Refsum H, Stensvold I, Tverdal A, et al. (1995) Total plasma homocysteine and cardiovascular risk profile. JAMA 274: 1526-33.
3. Kjaergard LL, Villumsen J, Gluud C, (2001) Reported methodologic quality and discrepancies between large and small randomized trials in meta-analyses. Annals of Internal Medicine 135: 982-9.
4. Stanley TD, Jarrell SB, Doucouliagos H, (2010) Could it be better to discard 90% of the data? A statistical paradox. The American Statistician 64: 70-7.
5. Kraemer HC, Gardner C, Brooks III JO, Yesavage JA, (1998) Advantages of excluding underpowered studies in meta-analysis: inclusionist versus exclusionist viewpoints. Psychological Methods 3: 23-31.
6. Merrall ELC, Kariminia A, Binswanger IA, Hobbs MS, Farrell M, et al. (2010) Meta-analysis of drug-related deaths soon after release from prison. Addiction 105: 1545-54.
7. Halpern SD, Karlawish JHT, Berlin JA, (2002) The continuing unethical conduct of underpowered clinical trials. JAMA 288: 358-62.
8. Edwards SJL, Lilford RJ, Braunholtz D, Jackson J, (1997) Why "underpowered" trials are not necessarily unethical. The Lancet 350: 804-7.
9. Guyatt GH, Mills EJ, Elbourne D, (2008) In the era of systematic reviews, does the size of an individual trial still matter? PLoS Medicine 5(1): e4.
10. Altman DG, (1994) The scandal of poor medical research. BMJ 308: 283.
11. Turner RM, Spiegelhalter DJ, Smith GCS, Thompson SG, (2009) Bias modelling in evidence synthesis. Journal of the Royal Statistical Society, Series A 172: 21-47.
12. Shrier I, Platt RW, Steele RJ, (2007) Mega-trials vs. meta-analysis: precision vs. heterogeneity? Contemporary Clinical Trials 28: 324-8.
13. Borm GF, Lemmers O, Fransen J, Donders R, (2009) The evidence provided by a single trial is less reliable than its statistical analysis suggests. Journal of Clinical Epidemiology 62: 711-5.
14. Moreno SG, Sutton AJ, Ades AE, Stanley TD, Abrams KR, et al. (2009) Assessment of regression-based methods to adjust for publication bias through a comprehensive simulation study. BMC Medical Research Methodology 9(2).
15. Rucker G, Carpenter JR, Schwarzer G, (2011) Detecting and adjusting for small-study effects in meta-analysis. Biometrical Journal 53: 351-68.
16. Davey J, Turner RM, Clarke MJ, Higgins JPT, (2011) Characteristics of meta-analyses and their component studies in the Cochrane Database of Systematic Reviews: a cross-sectional, descriptive analysis. BMC Medical Research Methodology 11: 160.
17. DerSimonian R, Laird N, (1986) Meta-analysis in clinical trials. Controlled Clinical Trials 7: 177-88.
18. Hedges LV, Pigott TD, (2001) The power of statistical tests in meta-analysis. Psychological Methods 6: 203-17.
19. Wetterslev JTK, Brok J, Gluud C, (2008) Trial sequential analysis may establish when firm evidence is reached in cumulative meta-analysis. Journal of Clinical Epidemiology 61: 64-75.
20. Brok J, Thorlund K, Gluud C, Wetterslev J, (2008) Trial sequential analysis reveals insufficient information size and potentially false positive results in many meta-analyses. Journal of Clinical Epidemiology 61: 763-9.
21. Thorlund K, Imberger G, Walsh M, Chu R, Gluud C, et al. (2011) The number of patients and events required to limit the risk of overestimation of intervention effects in meta-analysis- a simulation study. PLoS ONE 6(10): e25491.
22. Charles P, Giraudeau B, Dechartres A, Baron G, Ravaud P, (2009) Reporting of sample size calculation in randomised controlled trials: review. BMJ 338: b1732.
23. Nuesch E, Trelle S, Reichenbach S, Rutjes AWS, Tschannen B, et al. (2010) Small study effects in meta-analyses of osteoarthritis trials: meta-epidemiological study. BMJ 341: c3515.
24. Sterne JAC, Sutton AJ, Ioannidis JPA, Terrin N, Jones DR, et al. (2011) Recommendations for examining and interpreting funnel plot asymmetry in meta-analyses of randomised controlled trials. BMJ 343: d4002.
25. Watt A, Cameron A, Sturm L, Lathlean T, Babidge W, et al. (2008) Rapid reviews versus full systematic reviews: an inventory of current methods and practice in health technology assessment. International Journal of Technology Assessment in Health Care 24: 133-9.