Sources of heterogeneities in estimating the prevalence of endometriosis in infertile and previously fertile women

ObjectiveTo identify possible sources of heterogeneity in estimates of the prevalence of endometriosis in previously fertile women and in women with infertility.DesignA pooled analysis of previously published studies reporting prevalence estimates.SettingAcademic.PatientsNone.InterventionsNone.Main Outcome MeasuresNone.ResultsThere were tremendous heterogeneities in prevalence estimates for both the fertile and infertile groups. In addition, the prevalence estimates increased with the year of publication, but decreased with sample size. For previously fertile women, the heterogeneity in prevalence estimates was no longer significant after the effects of sample size and year of publication on estimates were taken into account. In the infertile group, however, there was still a sizeable heterogeneity unaccounted for after both sample size and year of publication were taken into account.ConclusionsA single prevalence estimate for the entire fertile or infertile group may be too simplistic at best. More precise prevalence estimates, likely to be age-dependent, await carefully designed and executed studies that will also record covariates such as age at surgery and referral patterns.