Adherence to postmenopausal hormone therapy during the year after the initial prescription: A population-based study

OBJECTIVE: In randomized trials a higher proportion of women prescribed con tinuous combined hormone replacement therapy complete the full course of tr eatment compared with those prescribed sequential therapy. Me sought to det ermine adherence to hormone therapy ina less-selected population. STUDY DESIGN: Women enrolled in a prepaid health plan participated in a tel ephone interview 12 to 15 months after newly initiating use of hormone repl acement therapy. The interview elicited information on whether the women we re still taking the hormones as first prescribed and reasons for switching or discontinuation. A computerized pharmacy database was used to determine initial doses, prescription renewal, and dates of switching or discontinuat ion. RESULTS: The proportion continuing the originally prescribed hormone regime n at 1 year was higher among continuous combined therapy users (68.9%, 62/9 0) than among sequential therapy users (54.4%, 62/114). Women who initiated continuous combined therapy were less likely to have switched regimens (10 .0%) than were sequential users (20.2%; relative risk, 0.5; 95% confidence interval, 0.2-1.0) but only somewhat less likely to have discontinued use ( 21.2% vs 25.4%; relative risk, 0.7; 95% confidence interval, 0.4-1.3). Exam ined as a whole, women prescribed continuous combined therapy were less lik ely than those prescribed sequential therapy to quit or switch during the f irst year (relative risk, 0.6; 95% confidence interval, 0.4-1.0). CONCLUSION: Although adherence was higher among women prescribed continuous combined hormone replacement therapy than sequential therapy, the high lev el of nonadherence in both groups suggests room for improvement of menopaus al therapies so that women find them acceptable for sustained use.