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KEEPS Confusing

April 16, 2013

The Kronos Early Estrogen Prevention Study (KEEPS click here)

Why would a randomised double-blind trial, which completed recruitment in June 2008 and whose participants presumably reached the final primary outcome at four years in June 2012, suddenly publish an unblinded substudy before the main trial report?  KEEPS did this in February (click here).

Were Mayo clinic participants unblinded just so that the effect of estrogen on bone density could be reported?  That’s hardly a major discovery. Is KEEPS really double blind?  Are centres able to break the blinding when they want to?

I’m sorry to be suspicious but KEEPS was designed to test the timing hypothesis for the effect of estrogen on cardiovascular diseases, i.e. the idea that it is cardioprotective for women within 10 years of the menopause, despite being clearly harmful later. Its authors are well known advocates of the timing hypothesis and many have received grants and lecture fees from companies marketing HRT. If they show a favourable effect of HRT on surrogate markers of cardiovascular disease they will surely trumpet it from the rooftops. Sceptics will want to be confident that those markers were measured blind.

Note for those readers who think they have already read the KEEPS results. You have, many times.  Here are some KEEPS publications:

But as far as I’m aware all these were observational studies on the whole cohort.

Jim Thornton

4 Comments leave one →
  1. JR1981 permalink
    August 21, 2014 12:00 am

    Well Jim, did you see a couple weeks ago that KEEPS failed royally? No slowing of CAC accumulation or CIMT. Of course the reasons are many – 1. women weren’t followed long enough 2. women were TOO healthy and their arteries didn’t change enough to detect a difference 3. progesterone negates estrogen’s “benefits” for arterial health.

    Nevertheless, the timing hypothesis will not die with KEEPS. If it didn’t happen with WHI, HERS or any other secondary prevention trial, then this wont be the last hurrah. (As a personal interest, I am very eager to see what hormones did to brain structure in KEEPS participants. I don’t think it will be good, not by a long shot. I also think estradiol may be WORSE than Premarin, especially in terms of breast cancer risk, as it’s much more potent than estrone sulfate conjuagtes.)


  1. More KEEPS confusion |
  2. KEEPS disappearing |

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