Summary of findings for the main comparison.
| Prophylactic chemotherapy compared with no prophylactic chemotherapy for hydatidiform mole | ||||||
|
Patient or population: women with a molar pregnancy Settings: inpatient Intervention: methotrexate or dactinomycin Comparison: placebo or no prophylaxis | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| No prophylaxis | P‐Chem | |||||
|
Incidence of GTN (including low‐quality studies) |
Mixed‐risk population | RR 0.37 (0.24 to 0.57) | 550 women (3 studies) | ⊕⊕⊝⊝ low | The NNTB to prevent 1 woman developing GTN after evacuation of HM was 6 (95% CI 5 to 10). We downgraded this evidence because this meta‐analysis included 2 studies that we considered to be of poor methodological quality | |
| 254 per 1000 | 94 per 1000 (61 to 145) | |||||
| High‐risk population |
RR 0.29 (0.14 to 0.60) |
99 women (2 studies) |
⊕⊕⊝⊝ low | The NNTB for women with high‐risk HM was 3 (95% CI 2 to 5). We downgraded this evidence because the meta‐analysis included 2 small studies, 1 of which was of a poor methodological quality | ||
| 490 per 1000 | 142 per 1000 (69 to 294) | |||||
|
Incidence of GTN (excluding low‐quality studies) |
High‐risk population | RR 0.28 (0.10 to 0.73) | 59 women (1 study) |
⊕⊕⊝⊝ low | The NNTB to prevent 1 woman developing GTN after evacuation of high‐risk HM was 3 (95% CI 2 to 20). We downgraded this evidence because only 1 small study (Limpongsanurak 2001) contributed data, giving an imprecise result | |
| 500 per 1000 | 140 per 1000 (50 to 365) | |||||
|
Time to GTN diagnosis (days) |
The mean time to GTN diagnosis ranged across control groups from 35.7 days to 59.5 days | The mean time to GTN diagnosis in the intervention groups was 65.5 days to 81.8 days (higher) | MD 28.72 (13.19 to 44.24) | 33 women (2 studies) | ⊕⊕⊝⊝ low | We downgraded this evidence because the meta‐analysis included 1 study of poor methodological quality (Kim 1986). When this study was excluded, the results of the remaining study (Limpongsanurak 2001; 19 women) were: MD 22.30; 95% CI ‐9.05 to 53.65 |
| Number of courses of chemotherapy to cure | The mean number of courses of chemotherapy required to cure subsequent GTN was 1.4 courses (10 women) | The mean number of courses of chemotherapy required to cure subsequent GTN was 2.5 courses (4 women) |
MD 1.10 (0.52 to 1.68) |
14 women (1 study) | ⊕⊝⊝⊝ very low | This analysis only included 1 study (Kim 1986) that we considered to be of a poor methodological quality |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; HM: hydatidiform mole; NNTB: number needed to treat for an additional beneficial outcome; RR: risk ratio; MD: mean difference; GTN: gestational trophoblastic neoplasia. | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
The assumed risk for the mixed‐risk population was calculated by using the weighted mean risk across the control group for this outcome. The assumed risk for the high‐risk population was based on the control group of Limpongsanurak 2001, which was the only study to evaluate a high‐risk population only.