what they said (Hover the mouse cursor over underlined words for more info)

A drug that needs to be injected only once a year can sharply reduce fractures in women suffering from the bone-weakening disease osteoporosis, according to a new study.
Annual treatment with zoledronic acid produced impressive results in a large clinical trial, including:
* A 70-per-cent reduction in spine fractures;
* A 41-per-cent drop in broken hips;
* A 25-per-cent reduction in other fractures, such as broken wrists.

The original article can be found at: http://www.theglobeandmail.com/servlet/story/RTGAM.20070503.wxlosteo03/BNStory/specialScienceandHealth/home

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what we said (Hover the mouse cursor over underlined words for more info)

The most significant failing of what is an otherwise good report is the use of misleading relative risk reductions when discussing the use of zoledronic acid. Such statistics exaggerate benefits and, when not put alongside the absolute risks of the treatment, are not helpful for readers. The story fails to mention the larger context and the somewhat checkered history of bisphosphonate drugs, especially in the recent evidence around the links of these drugs to osteonecrosis of the jaw.
While it reports that this intravenous, once yearly drug can produce a "70-per-cent reduction in spine fractures; a 41-per-cent drop in broken hips and a 25-per-cent reduction in other fractures, such as broken wrists, " the reader never learns what the actual risks are to start with, so these figures are, for the most part unhelpful. The press release unfortunately did not deliver these details, either, but a quick web search revealed what was published in the New England Journal, primarily: "Zoledronic acid treatment reduces the risk of morphometric vertebral fractures by an absolute 7.6% over three years, compared with placebo (3.3% in the zoledronic-acid group versus 10.9% in the placebo group; The risk of hip fracture was reduced by 1.1% (1.4% in the zoledronic group versus 2.5% in the placebo. "
In other words, instead of leaving the reader with the impression that 40 out of 100 women would benefit from taking the drug and avoiding a hip fracture (the most crucial worry about osteoporosis) that number should be closer to one out of 100.
Another misleading aspect of this article is the impressive "70% reduction in vertebral fractures" which sounds exciting but are less so when we consider that these are 'morphometric' vertebral fractures, the type only visible on x-ray and asymptomatic. Patients don't feel them.
Non-drug alternatives in the prevention of hip fractures (better eyeglasses, exercise, yoga, etc) could have been mentioned as there is some very strong evidence as to the benefits of these alternative therapies.

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