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Wednesday, May 28, 2003Hormone replacement therapy for post-menopausal women took a hit on Tuesday -- the second one in 10 months. Women who begin taking combined estrogen-progestin compounds after the age of 65 double their risk of developing dementia, according to the just-released results of a large federal study. Most of the dementia was classified as Alzheimer's disease. While the number of women who developed symptoms of dementia while on hormones was twice the number of those on a placebo, the numbers were small -- 45 women in 10,000 on the hormones compared to 22 out of the 10,000 on a placebo. So, the incidence of Alzheimer’s in hormone replacement users was 0.0045%. The incidence in non-users, 0.0022%. Hardly a dramatic difference. Yet, the authors framed the difference in much more dramatic terms in their abstract: Overall, 61 women were diagnosed with probable dementia, 40 (66%) in the estrogen plus progestin group compared with 21 (34%) in the placebo group. Perspective is everything. Too bad the researchers responsible for the WHIMS have such a tendency to hysteria. They indulge in even more hysteria in two other studies in this week’s JAMA. In one, they compared hormone replacement users’ with non-users’ performance on a mental status examination, called the Modified Mini-Mental State Exam: The Modified Mini-Mental State Examination mean total scores in both groups increased slightly over time (mean follow-up of 4.2 years). Women in the estrogen plus progestin group had smaller average increases in total scores compared with women receiving placebo (P = .03), but these differences were not clinically important. Removing women by censoring them after adjudicated dementia, mild cognitive impairment, or stroke, and nonadherence to study protocol, did not alter the findings. Prior hormone therapy use and duration of prior use did not affect the interpretation of the results, nor did timing of prior hormone therapy initiation with respect to the final menstrual period. More women in the estrogen plus progestin group had a substantial and clinically important decline (2 SDs) in Modified Mini-Mental State Examination total score (6.7%) compared with the placebo group (4.8%) (P = .008). In other words, the actual scores weren’t all that different between the two groups. And, in fact, their raw data show that mean scores were essentially the same. But, they managed to find a difference by converting the scores to “mean rates of change,” thus exaggerating a very small, clinically insignificant difference into a more ominous sounding, but equally clinically insignificant, difference. Their conclusion that there is a “small increased risk of clinically meaningful cognitive decline” in hormone replacement users is disingenous at best. The other study claims an increased risk of stroke in hormone replacement users (also found in last years attention-grabbing study.) The researchers begin the comment section of the paper with this obesrvation: In this clinical trial involving 16,608 postmenopausal women, those taking estrogen plus progestin had an approximate 31% increase in total stroke risk compared with those taking placebo. But here’s the actual data: One hundred fifty-one patients (1.8%) in the estrogen plus progestin and 107 (1.3%) in the placebo groups had strokes. I think the media is catching on, however. Here’s the Wichita Eagles’ take on the study: In the journal articles today, the researchers said women taking the hormone combination had twice the risk of developing dementia as women taking the placebo. They also said the women on hormones had an increased risk of cognitive decline. And, they said, the women had a 31 percent increased risk of stroke, confirming study results from a year ago. Those numbers are scary, Grainger said, but they should be looked at in terms of "relative risk" and "absolute risk." For example, 1.8 percent of the women taking the hormones had strokes, compared with 1.3 percent of those taking the placebo. That means those taking the hormones were 31 percent more likely to have a stroke, he said. That's the relative risk. But the absolute risk of stroke in both groups was low -- 151 patients among 8,506 in the hormone group and 107 among the 8,102 in the placebo group had strokes. Now, all we have to do is get them to stop reporting the hyped up “relative risks” and “relative rate of increase” numbers and just give the public the straight dope. posted by Sydney on 5/28/2003 09:10:00 AM 0 comments 0 Comments: |
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