Table 2.
Number (%) of statistically significant Cochrane meta-analyses according to the DerSimonian-Laird and Hartung-Knapp-Sidik-Jonkman methods
| Outcome | Selected meta-analyses | N | DL test significant | HKSJ test significant | HKSJ test not significant, positive DL test |
|---|---|---|---|---|---|
| Continuous |
All |
255 |
130 (51.0) |
102 (40.0) |
31/130 (23.8) |
| |
Ratio > 5, < = 5 studies |
46 |
22 (47.8) |
13 (28.3) |
13/22 (59.1) |
| Dichotomous |
All |
434 |
185 (42.6) |
147 (33.9) |
48/185 (25.9) |
| Ratio > 5, < = 5 studies | 76 | 28 (36.8) | 15 (19.7) | 14/28 (50.0) |
All: all meta-analyses with a continuous or dichotomous outcome that fulfilled the following criteria: the first meta-analysis in a review in the Cochrane Database for Systematic Reviews Issues of 2012, based on at least three studies. Ratio >5, < = 5 studies: a selection of these meta-analyses based on at most five studies, where the ratio of the largest vs. the smallest trial size was > 5. DL: DerSimonian & Laird meta-analysis method. HKSJ: Hartung-Knapp-Sidik-Jonkman meta-analysis method. DL test significant: DL p-value <0.05; HKSJ test significant: HKSJ p-value < 0.05. Note that in a few cases the HKSJ test was significant when the DL test was not.