Premium
Assessing the potential for bias in meta‐analysis due to selective reporting of subgroup analyses within studies
Author(s) -
Hahn Seokyung,
Williamson Paula R.,
Hutton Jane L.,
Garner Paul,
Flynn E. Victor
Publication year - 2000
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/1097-0258(20001230)19:24<3325::aid-sim827>3.0.co;2-d
Subject(s) - subgroup analysis , publication bias , meta analysis , missing data , medicine , econometrics , medline , statistics , computer science , mathematics , political science , law
Subgroup analysis is frequently used to investigate heterogeneity in meta‐analysis. Subgroup data are not always available, and researchers should record what data were available for each trial. If data were not available, and it is known that the subgroup data were collected, the potential for selective reporting should be considered. Bias due to selective publishing of reports is widely recognized in meta‐analysis. In contrast, selective reporting within studies is little discussed but potentially important. We explored this problem by evaluating the effect of potential bias in subgroup analysis due to within‐study selective reporting with an existing meta‐analysis. The review addressed malaria chemoprophylaxis in pregnancy. The conclusion in the original review, that benefit is limited to primigravidae, was based on subgroup analysis using the three trials out of five which reported on subgroups. We developed a method of sensitivity analysis that imputes data for the missing subgroups to assess the robustness of the results and the conclusions drawn. In this particular example, our analysis indicates that the estimate of effect reported in the review is most likely to overestimate the true effect and the conclusion that benefit is limited to primigravidae may be false. Copyright © 2000 John Wiley & Sons, Ltd.