JOURNAL ARTICLE

Combined postmenopausal hormone therapy and cardiovascular disease: toward resolving the discrepancy between observational studies and the Women's Health Initiative clinical trial

Ross L Prentice, Robert Langer, Marcia L Stefanick, Barbara V Howard, Mary Pettinger, Garnet Anderson, David Barad, J David Curb, Jane Kotchen, Lewis Kuller, Marian Limacher, Jean Wactawski-Wende et al.
American Journal of Epidemiology 2005 September 1, 162 (5): 404-14
16033876
Observational research on postmenopausal hormone therapy suggests a 40-50% reduction in coronary heart disease incidence among women using these preparations. In contrast, the Women's Health Initiative clinical trial of estrogen plus progestin found an elevated incidence over a 5.6-year intervention period through July 7, 2002. Toward explaining this discrepancy, the authors analyzed data from this trial, which included 16,608 postmenopausal women aged 50-79 years, and corresponding data from 53,054 women in the Women's Health Initiative observational study, 33% of whom were estrogen-plus-progestin users at baseline. Estrogen-plus-progestin hazard ratio estimates for coronary heart disease, stroke, and venous thromboembolism in the observational study were 39-48% lower than those in the clinical trial following age adjustment. However, hazard ratios tended to decrease with increasing time from initiation of estrogen-plus-progestin use, and observational study hazard ratio estimates are heavily weighted by longer-term use while clinical trial hazard ratio estimates reflect shorter-term use. Following control for time from estrogen-plus-progestin initiation and confounding, hazard ratio estimates were rather similar for the two cohorts, although there was evidence of some remaining difference for stroke. These analyses have implications for both the design and the analysis of observational studies.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
16033876
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"