Importance: It is uncertain whether hormone therapy should be used for the primary prevention of chronic conditions such as heart disease, osteoporosis, or some types of cancers.
Objective: To update evidence for the US Preventive Services Task Force on the benefits and harms of hormone therapy in reducing risks for chronic conditions.
Data sources: PubMed/MEDLINE, Cochrane Library, EMBASE, and trial registries from January 1, 2016, through October 12, 2021; surveillance through July 2022.
Study selection: English-language randomized clinical trials and prospective cohort studies of fair or good quality.
Data extraction and synthesis: Dual review of abstracts, full-text articles, and study quality; meta-analyses when at least 3 similar studies were available.
Main outcomes and measures: Morbidity and mortality related to chronic conditions; health-related quality of life.
Results: Twenty trials (N = 39 145) and 3 cohort studies (N = 1 155 410) were included. Participants using estrogen only compared with placebo had significantly lower risks for diabetes over 7.1 years (1050 vs 903 cases; 134 fewer [95% CI, 18-237]) and fractures over 7.2 years (1024 vs 1413 cases; 388 fewer [95% CI, 277-489]) per 10 000 persons. Risks per 10 000 persons were statistically significantly increased for gallbladder disease over 7.1 years (1113 vs 737 cases; 377 more [95% CI, 234-540]), stroke over 7.2 years (318 vs 239 cases; 79 more [95% CI, 15-159]), venous thromboembolism over 7.2 years (258 vs 181 cases; 77 more [95% CI, 19-153]), and urinary incontinence over 1 year (2331 vs 1446 cases; 885 more [95% CI, 659-1135]). Participants using estrogen plus progestin compared with placebo experienced significantly lower risks, per 10 000 persons, for colorectal cancer over 5.6 years (59 vs 93 cases; 34 fewer [95% CI, 9-51]), diabetes over 5.6 years (403 vs 482 cases; 78 fewer [95% CI, 15-133]), and fractures over 5 years (864 vs 1094 cases; 230 fewer [95% CI, 66-372]). Risks, per 10 000 persons, were significantly increased for invasive breast cancer (242 vs 191 cases; 51 more [95% CI, 6-106]), gallbladder disease (723 vs 463 cases; 260 more [95% CI, 169-364]), stroke (187 vs 135 cases; 52 more [95% CI, 12-104]), and venous thromboembolism (246 vs 126 cases; 120 more [95% CI, 68-185]) over 5.6 years; probable dementia (179 vs 91 cases; 88 more [95% CI, 15-212]) over 4.0 years; and urinary incontinence (1707 vs 1145 cases; 562 more [95% CI, 412-726]) over 1 year.
Conclusions and relevance: Use of hormone therapy in postmenopausal persons for the primary prevention of chronic conditions was associated with some benefits but also with an increased risk of harms.