OBJECTIVES: For use in a cost-effectiveness model, synthesize available data to derive estimates of efficacy for several classes of treatments for heavy menstrual bleeding (HMB). METHODS: A systematic review identified randomized controlled trials that reported data on menstrual blood loss (MBL) at baseline and one or more follow-up times.  The primary measure of efficacy was the proportion of women who achieved MBL <80mL per cycle (month), as measured by the alkaline hematin method.  Complicating the analysis, some trials reported various summary statistics for MBL, and others used scores from pictorial blood-loss assessment charts (PBAC).  Estimation of the primary measure from those diverse data took advantage of the approximately lognormal distributions of MBL and PBAC scores.  Also, reported follow-up times varied substantially.  Estimates of efficacy by treatment class and time were obtained from a Bayesian mixed treatment comparison (MTC) model.  The model also included effects for treatment class, study, and the combination of treatment class and study and an adjustment for baseline mean MBL. RESULTS: The evidence network comprised eight treatment classes and 34 randomized clinical trials (RCTs), with follow-up times from 1 to 36 months.  Efficacy at three months of follow-up (estimated as the posterior median) ranged from 87.5% for the levonorgestrel-releasing intrauterine system (LNG-IUS) to 14.2% for progestogens administered for less than two weeks out of four in the menstrual cycle.  The 95% credible intervals for most estimates were quite wide, mainly because of the limited evidence for many combinations of treatment class and follow-up time and the uncertainty from estimating %MBL<80mL from other outcome data. CONCLUSIONS: LNG-IUS and endometrial ablation have high efficacy for HMB.  The study yielded useful insights on MTC in sparse evidence networks.  Diversity of outcome measures and follow-up times in the HMB literature presented considerable challenges.  The Bayesian credible intervals reflected the various sources of uncertainty.