Effect size assessment and recalculation of statistical significance in selected studies of STI intervention
| Study | Outcome | Control | Treatment | Effect size (%) | h Value | Cohen’s h classification | Untransformed | Transformed | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No | (%) | No | (%) | z test | Result | t test | Result | |||||
| Ford, 20026 | Syphilis | 6.8 (1489) | 3.6 (359) | 3.2 | 0.06 | small | 2.71 | Significant | 1.73 | NS | ||
| Trichomoniasis | 7.9 (1489) | 3.5 (359) | 4.4 | 0.09 | small | 3.68 | Significant | 2.36 | Significant | |||
| Gonorrhoea | 62.0 (1489) | 43.0 (359) | 19.0 | 0.45 | medium | 6.55 | Significant | 6.51 | Significant | |||
| Chlamydia | 43.0 (1489) | 41.0 (359) | 2.0 | 0.04 | small | 0.69 | NS | 0.69 | NS | |||
| Golden, 19967 | Gonorrhoea (men) | 8.3 (468) | 3.6 (400) | 4.7 | 0.09 | small | 2.98 | Significant | 2.05 | Marginal | ||
| Gonorrhoea (women) | 2.9 (140) | 6.0 (149) | −3.1 | −0.06 | small | −1.29 | NS | −0.83 | NS | |||
| Syphilis (men) | 1.7 (468) | 0.75 (400) | 0.95 | 0.02 | small | 1.29 | NS | 0.61 | NS | |||
| Syphilis (women) | 0.0 (140) | 0.67 (149) | −0.67 | −0.01 | small | −1.00 | NS | − | NS | |||
| O’Donnell, 19988 | New STD | 26.8 (794) | 22.5 (1210) | 4.3 | 0.09 | small | 2.17 | Significant | 2.02 | Marginal | ||