The authors of this week‘s BMJ paper believe that this represents a classic case of disease-mongering: a risk factor being transformed into a medical disease in order to sell tests and drugs to relatively healthy people.
Osteopenia or pre-osteoporosis is said to affect around half of all older women and, in at least one country, drug companies have already begun to market their drugs to women with osteopenia, based on re-analyses of four osteoporosis drug trials.
But the authors argue that this move raises serious questions about the benefit-risk ratio for low risk individuals, and about the costs of medicalising and potentially treating an enormous group of healthy people. These reanalyses tend to exaggerate the benefits of drug therapy, they say. For example, the authors of one reanalysis cite a 75% relative risk reduction, though this translates into only a 0.9% reduction in absolute risk.
In other words, up to 270 women with pre-osteoporosis might need to be treated with drugs for three years so that one of them could avoid a single vertebral fracture.
Most of the reanalyses also play down the harms of drug therapy, they add. For example, the reanalysis of data for the drug raloxifene focuses solely on the potential benefits, with no mention of an increased risk of blood clots.
Finally, like much of the published literature on osteoporosis, these analyses have potential conflicts of interest, they write. For instance, all of the original drug trials being re-analysed were funded by industry and, in three out of four cases, drug company employees were part of the team conducting the reanalyses.
MEDICA.de; Source: BMJ-British Medical Journal