Table 3.
Results of the weighted ANOVAs for the influence of methodological quality items on the effect sizes
| Quality item | k | r+ | 95% CI | ANOVA results | |
|---|---|---|---|---|---|
| rl | ru | ||||
| 1. Probabilistic sampling | QB(1) = 0.988, p = .320 | ||||
| Yes | 1 | .280 | .127 | .420 | R2 = .00 |
| No | 35 | .359 | .299 | .415 | QW(34) = 202.124, p < .001 |
| 2. Adequate target population | QB(1) = 1.118, p = .290 | ||||
| Yes | 24 | .380 | .310 | .446 | R2 = .01 |
| No | 12 | .316 | .215 | .411 | QW(34) = 191.814, p < .001 |
| 4. Reliability/validity MD measurement tool | QB(1) = 6.928, p = .008 | ||||
| Yes | 24 | .403 | .331 | .470 | R2 = .13 |
| No | 12 | .255 | .167 | .339 | QW(34) = 192.883, p < .001 |
| 5. Reliability/validity ED measurement tool | QB(1) = 26.172, p < .001 | ||||
| Yes | 24 | .416 | .349 | .479 | R2 = .31 |
| No | 12 | .196 | .147 | .244 | QW(34) = 159.323, p < .001 |
| 6. Absence of dichotomous DM and ED | QB(1) = 6.412, p = .011 | ||||
| Yes | 30 | .376 | .314 | .434 | R2 = .06 |
| No | 6 | .219 | .109 | .324 | QW(34) = 186.515, p < .001 |
| 8. Statistical test appropriate | QB(1) = 0.058, p = .810 | ||||
| Yes | 21 | .360 | .280 | .435 | R2 = .00 |
| No | 15 | .346 | .265 | .423 | QW(34) = 202.325, p < .001 |
| 9. Private financial support | QB(1) = 0.138, p = .711 | ||||
| Yes | 4 | .373 | .288 | .452 | R2 = .00 |
| No | 32 | .354 | .290 | .414 | QW(34) = 201.692, p < .001 |
| 10. Statistical power | QB(1) = 0.426, p = .514 | ||||
| Yes | 2 | .251 | −.101 | .548 | R2 = .00 |
| No | 34 | .361 | .302 | .418 | QW(34) = 202.397, p < .001 |
Note. Results for item 3 (dropouts were similar in socio-demographic characteristics to those of the final sample) and item 7 (absence of reporting bias) were not analyzed because all studies scored 0 and 1, respectively. k: number of studies; r+: mean effect size; rl and ru: 95% lower and upper confidence limits around r+; QB: between-categories Q statistic; QW: within-categories Q statistic; R2: proportion of variance accounted for by the moderator variable; ANOVA: analysis of variance; ED: eating disorder; MD: muscle dysmorphia.