A Cochrane systematic review and meta-analysis «Schroll JB, Black AY, Farquhar C, et al. Combined ...»1 compared combined oral contraceptive pills with placebo, with other OCPs and NSAIDs in the treatment of primary dysmenorrhoea.
Pooled data suggested a moderate impact on dysmenorrhea related pain (SMD −0.58, 95% CI −0.74 to −0.41; I² = 28%; 6 RCTs, n=588). The impact translates to an improvement of 0.8 points on the Total Dysmenorrhoea Score (0-6).
OCPs increased the risk of any adverse events (RR 1.31, 95% CI 1.20 to 1.43; I² = 79%; 7 RCTs, n=1025). Of specific single adverse effects OCPs increased the risk of irregular bleeding (absolute risk difference [ARD] 24 %), headaches (ARD 0.14), nausea (ARD 0.07), and weight gain (ARD 0.06).
The evidence certainty was downgraded one time due to risk of bias and imprecision.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis | |||||
| «Schroll JB, Black AY, Farquhar C, et al. Combined ...»1 | SR/MA of RCTs | Women with primary dysmenorrhoea in outpatient settings | Combined oral contraceptive pills vs placebo | Post-treatment pain and adverse events | Moderate |
| Reference | Comments |
|---|---|
| «Schroll JB, Black AY, Farquhar C, et al. Combined ...»1 | Some risk of bias due to unclear study protocols on randomization and blinding in some of the studies and apparent lack of proper protocols in one old study. Most studies were sponsored by pharma industry. |
Results
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (%) I | Absolute number of events (%) C | SMD (95% CI) |
|---|---|---|---|---|---|
| Level of evidence: moderate The evidence was downgraded due to study limitations. I= intervention; C=comparison; CI=confidence interval |
|||||
| «Schroll JB, Black AY, Farquhar C, et al. Combined ...»1 | 6 studies, 588 patients (328/260) | 3-4 months | N/A | N/A | -0.58 (-0.74,-0.41) |
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (%) I | Absolute number of events (%) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| Level of evidence: moderate The evidence was downgraded due to study limitations I= intervention; C=comparison; CI=confidence interval |
|||||
| «Schroll JB, Black AY, Farquhar C, et al. Combined ...»1 | 8 studies, 1025 patients (652/373) | 3-4 months | 536 (82%) | 220 (59%) | 1.31 [1.20,1.43] |