Osteoporosis guidelines

In most respects, the guidelines for the diagnosis and management of osteoporosis, developed by the Osteoporosis Society of Canada,¹ are excellent. However, they suffer from 2 serious deficiencies.

First, all descriptions of the benefits of therapy are provided as relative risk reductions, with no mention of absolute risk reductions or numbers needed to treat (although, interestingly, the small increase in venous thrombosis associated with use of raloxifene is described as an absolute risk).¹ From a clinical point of view, absolute benefits and risks markedly influence therapeutic decisions. This is particularly important in the prevention and treatment of osteoporosis, because the risk of fracture without therapy varies so much with the patient's characteristics. Groups such as the American College of Physicians Journal Club mandate that both absolute and relative risk reductions be provided when describing the benefits of a therapy.² I am surprised that CMAJ does not have a similar policy.

Second, the guidelines make no mention of cost-effectiveness. I believe that cost-effectiveness should be mentioned for any guidelines that could affect the medical management of a large number of Canadians. In my experience, these guidelines are now being used by clinicians and pharmaceutical companies to convince those who pay for osteoporosis drugs to loosen their restrictions on reimbursement. Because most payers consider cost-effectiveness as well as medical effectiveness, the guidelines would be more influential if they provided good evidence of cost-effectiveness.

Andreas Laupacis President and Chief Executive Officer Institute for Clinical Evaluative Sciences Toronto, Ont.