Rationale and design of the Kronos Early Estrogen Prevention Study (KEEPS) and the KEEPS Cognitive and Affective sub study (KEEPS Cog).

This manuscript describes the study design and rationalle for the Kronos Early Estrogen Prevention Study (KEEPS) and the KEEPS Cognitive and Affective ancillary study (KEEPS Cog). KEEPS is a multicenter, randomized, double-blinded, placebo-controlled trial, designed to test the hypothesis that low-dose hormone therapy (HT) initiated in recently postmenopausal women will reduce the progression of subclinical atherosclerosis as measured by carotid artery intima-media thickness (CIMT) and coronary artery calcification (CAC) over four years. The KEEPS Cog ancillary study was designed to assess potential estrogenic treatment effects on cognition and mood. We present the KEEPS trial in the context of issues raised by the Women's Health Initiative (WHI) and the Women's Health Initiative Memory Study (WHIMS). Here we also describe the most recent results and ongoing HT-related research studies designed to address similar issues. This article is part of a Special Issue entitled Hormone Therapy.