Abstract
In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if a body of evidence is associated with a high risk of publication bias. Even when individual studies included in best-evidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. Publication bias is likely frequent, and caution in the face of early results, particularly with small sample size and number of events, is warranted.
Original language | English (US) |
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Pages (from-to) | 1277-1282 |
Number of pages | 6 |
Journal | Journal of Clinical Epidemiology |
Volume | 64 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2011 |
Keywords
- Conflict of interest
- Funnel plot
- GRADE
- Pharmaceutical industry
- Publication bias
- Quality of evidence
ASJC Scopus subject areas
- Epidemiology