Predictors of difficulty when discontinuing postmenopausal hormone therapy

OBJECTIVE: To describe the experiences of postmenopausal women who try to stop hormone therapy and to identify characteristics associated with inability to stop. METHODS: We conducted telephone interviews with 377 randomly selected female members of the Kaiser Foundation Health Plan, aged 50-69 years, who regularly used hormone therapy for at least 1 year before July 1, 2002 and had attempted to stop between July 2002 and March 2003. RESULTS: Of the 377 women, 280 (74%) successfully stopped and 97 (26%) resumed taking hormone therapy. The major predictor of resuming hormone therapy use was the development of troublesome withdrawal symptoms (odds ratio 8.8; 95% confidence interval 4.9, 16.0). Report of hysterectomy, hormone therapy prescribed by a nongynecologist, and perception of high risk of hip or spine fracture were independently associated with a higher likelihood of unsuccessful stopping. Women with a hysterectomy who had used hormone therapy for 10 or more years and who started hormone therapy mainly for reasons other than health promotion were more likely (P <.001) to be unsuccessful in quitting (44%) compared with those with one or two (25%) or none (9%) of these three characteristics. Most successful stoppers (71%) stopped hormone therapy abruptly, but 29% tapered off hormone therapy; there was no difference in the incidence of troublesome withdrawal symptoms or successful quitting between these two groups. CONCLUSION: Approximately one quarter of women who try to stop report that they are unable to discontinue postmenopausal hormone therapy, primarily because they develop troublesome withdrawal symptoms. Effective approaches to reducing hormone therapy withdrawal symptoms should be a priority for future research.