Objective: To determine the incidence of subsequent leiomyoma surgery following myomectomy in a population-based cohort.
Methods: All women, ages 20-75 years, enrolled in a large HMO in Washington State, identified by CPT and ICD-9 codes as having a myomectomy between January 1, 1993, and December 31, 2002, were eligible for the study. The follow-up period was 0.1-11 years. Automated enrollment and inpatient, outpatient, pathology, and procedure data were linked. Age-adjusted hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazard models, age-specific Kaplan Meier estimates of cumulative risk, and incidence of uterine surgery after myomectomy were calculated.
Results: Among 628 eligible women, 127 (21.8%) had a second surgery, 95 (74.8%) of which were hysterectomies. The cumulative incidence of a second surgery was 23.5% at 5 years and 30% at 7 years. During 2766.5 woman-years of follow-up, the annual incidence of a subsequent myoma surgery was 4.6%. Compared with women aged 40-44, women >or=50 had a 50% decreased risk for subsequent surgery (HR = 0.5, 95% CI 0.3-0.9).
Conclusions: The incidence of subsequent surgery for leiomyomas following myomectomy is high, almost 5% per year.