Association Between Endometriosis/Uterine Fibroids and Premature Mortality: Findings from the NHANES 1999–2006 Data

Previous research on endometriosis and uterine fibroids has primarily focused on single-disease analyses and specific health outcomes. This investigation examined potential links between both conditions and early mortality. The analysis was based on the NHANES data in a prospective cohort design, with 5402 female participants grouped based on self-reported medical histories. Standardized interview questionnaires were used to gather baseline demographic characteristics and disease-related covariates. We conducted weighted Cox proportional hazards analyses, performing both unadjusted and adjusted regression models. Further stratification was conducted to examine potential variations across subgroups. A total of 273 premature deaths were recorded. Endometriosis was significantly associated with premature mortality in the unadjusted model (hazard ratio [HR] = 2.15, 95% confidence interval (CI) 1.35–3.42), with persistent significance after demographic adjustment (HR = 1.68, 95% CI 1.08–2.60) and full adjustment (HR = 1.77, 95% CI 1.15–2.75). Uterine fibroids showed initial significance (unadjusted HR = 1.77, 95% CI 1.18–2.68) but were weakened after demographic adjustment (adjusted HR = 1.07, 95% CI 0.69–1.66). Subgroup analysis results indicated that the risk of premature mortality in patients with endometriosis varied significantly across different populations. The significance was elevated in individuals with less than a high school education (HR = 2.99, 95% CI 1.53–5.84) and nondrinkers (HR = 2.45, 95% CI 1.27–4.73) in the stratified analysis of uterine fibroids. No other significant interactions were observed. Our study demonstrated that endometriosis independently contributes to heightened premature death risk. The link between uterine fibroids and premature mortality presents risk patterns specific to subgroups.