LONG-TERM RISK OF HYSTERECTOMY AMONG 80,007 STERILIZED AND COMPARISON WOMEN AT KAISER PERMANENTE, 1971-1987

To study the long-term risk of hysterectomy after tubal sterilization, the authors analyzed historical hospital discharge data on 39,502 parous women sterilized during 1971-1984 and 40,505 comparison women matched on age, race, parity, and interval since last birth. Sterilized women were significantly more likely than were comparison women to undergo hysterectomy (relative risk (RR) = 1.35, 95% confidence interval (CI) 1.26-1.44), especially for diagnoses of menstrual dysfunction and pelvic pain (RR = 1.88, 95% CI 1.65-2.13). Higher relative risks were not associated with greater tissue-destructive methods of tubal occlusion. Relative risks were highest for women who were young on the reference date (RR = 2.45, 95% CI 1.79-3.36 for women aged 20-24 years), but declined steadily as age increased (RR = 0.96, 95% CI 0.72-1.28 for women aged 40-49 years). In all age groups, relative risks were significantly above 1.00 after 7 years of follow-up. Reasons for elevated risks may be related to a greater willingness of sterilized women to forgo their uteruses. The emergence of greater risk in all age groups, however, prevents the authors from ruling out a possible latent biologic effect of tubal sterilization.