Pharmaceutical companies push a number of drugs to treat pre-osteoporosis or "osteopenia," but are they really necessary?

New research published in the British Medical Journal suggests millions of low risk women are being encouraged to seek treatment and take drugs they don't need.

The authors don't mince words, calling it "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, led by Pablo Alonso-Coello of Hospital de Sant Pau in Barcelona, argue the move raises serious questions about the benefit-risk ratio for low risk individuals, and about the costs of medicalizing and potentially treating an enormous group of healthy people.

"These re-analyses tend to exaggerate the benefits of drug therapy," the researchers write. "For example, the authors of one reanalysis cite a 75 percent relative risk reduction, though this translates into only a 0.9 percent 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 re-analyses also play down the risks 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, the authors write. "For instance, all of the original drug trials being re-analyzed were funded by industry and, in three out of four cases, drug company employees were part of the team conducting the reanalyses."

The World Health Organization is currently developing guidance on how to deal with women categorized as having osteopenia.

"We need to ask whether the coming wave of marketing targeting those women with pre-osteoporosis will result in the sound effective prevention of fractures or the unnecessary and wasteful treatment of millions more healthy women," the authors conclude.