Where have the KEEPS trial results gone?
The Kronos Early Estrogen Prevention Study (KEEPS) was an important investigator-led randomised trial funded by a charity, the Kronos Institute. The KEEPS researchers tested the controversial hypothesis that hormone therapy (HT*), started soon after the menopause, was cardioprotective. The trial was registered here. The primary endpoint, a surrogate for heart attacks and strokes, was the rate of change in carotid intimal medial thickness (CIMT) over the four years post-randomisation. 728 women were enrolled and the final four year data collected in May 2012. So far no publication, or electronic pre-publication has appeared.
This is a bit slow. The results were presented at the North American Menopause Society in October 2012. According to the abstract:
“The carotid ultrasound studies showed similar rates of progression of arterial wall thickness in all three treatment groups over the four years of study. These changes were generally small, limiting the statistical power to detect any differences among the groups.”
i.e. it appears the trial was negative. This would be important for those gynaecologists who encourage the taking of HT, some even in the absence of symptoms, in the early years after the menopause. But only if they can read the details.
The investigators have published many papers based on other bits of trial data (click here), as well as some randomised results based on a subset of 76 participants (click here)! But no results for the trial primary outcome in a peer reviewed journal.
The reason for concern is that some of the authors have potential conflicts of interest with HT manufacturers, and they’ve issued two press releases suggesting beneficial effects on other secondary outcomes and in trial subsets (here pr_100312_a and here pr_100312). These have been used by medical journalists e.g. here, here and here, and in many other publications, to imply that HT is beneficial for younger post menopausal women.
Surely independent academic researchers wouldn’t suppress the main trial results just because they failed to support their hypothesis! Would they?
*Hormone replacement therapy (HRT) changed to hormone therapy (HT) Jan 2016