| Ref ID | 332 |
| First Author | L. Furuya-Kanamori |
| Journal | JOURNAL OF CLINICAL EPIDEMIOLOGY |
| Year Of Publishing | 2020 |
| URL | https://www.jclinepi.com/article/S0895-4356(19)30381-6/fulltext |
| Keywords |
• General medical • Publication bias |
| Problem(s) |
• Poor consideration of publication bias • Weaknesses identified in some Cochrane reviews |
| Article Type | Empirical |
| Article Subtype | Cross-sectional survey/Methodological systematic review |
| First Author Country | Australia |
| Aim | To assess the effect of number of studies in a meta-analysis on the detection of publication bias using P value-driven methods in Cochrane reviews published 2003-2018. |
| Level of Investigation | Descriptive |
| Summary of Findings | The proportion of meta-analyses detected as asymmetrical via Egger’s, Harbord’s, Peters’, and Begg’s tests decreased by 42.6%, 41.1%, 29.3%, and 28.3%, respectively, when the median number of studies in the meta-analysis decreased from 87 to 14. P values decreased as the number of studies increased in the meta-analysis, despite the level of symmetry remaining constant. The simulation study confirmed that when publication bias is present, P value tests underestimate the presence of publication bias, particularly when study numbers are small. |
| Number of systematic reviews included | 5014 |
| Number of eligible systematic reviews assessed | 18229 |
| Treatment impacted | No |
| Treatment impacted description | |
| Interpretation impacted | Not Applicable |
| Interpretation impacted description |