Risedronate versus Alendronate study

Apr 3 2007

The largest retrospective, observational study comparing two osteoporosis therapies on the basis of fracture reduction was presented  at the Seventh European Congress on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ECCEO) in Porto, Portugal.

Patients taking the osteoporosis treatment risedronate (Actonel, risedronate sodium) were almost half as likely to sustain a hip fracture as those taking alendronate in the first year of treatment, according to the REAL (Risedronate, Alendronate) study.

Only a few "head-to-head" observational studies, or comparative effectiveness studies, have been conducted in the field of osteoporosis. Beyond the safety and efficacy data provided by placebo-controlled randomized trials, healthcare professionals have increasingly expressed interest in more head-to-head data comparing therapies on the relevant clinical endpoint, fracture.

Today experts are highlighting that well-designed comparative effectiveness studies can help advance our clinical knowledge where little data exists. Dr. Olaf Klungel, Associate Professor, Division of Pharmacoepidemiology and Pharmacotherapy, University of Utrecht, Netherlands, is a leading expert in the field of comparative effectiveness study design.

"There is a wealth of data available from large healthcare databases that enable us to research important clinical questions," said Dr. Klungel, "Robust methodology exists for comparing different therapies through observational database analysis. We must advance physicians' understanding and evaluation of these studies so that they can confidently integrate the information into their clinical decisions, when appropriate."

Physicians want to know the impact of their clinical decisions on the disease outcomes that matter most to patients. In the cardiovascular area, observational methods have been applied to compare antihypertensive therapies on the relevant outcomes of heart attack and stroke.2,3 In osteoporosis, similar methods are now being applied to compare therapies on the basis of fracture.

REAL, a retrospective cohort study, included 33,830 women newly treated with once-weekly doses of either Actonel or alendronate in 'real-life' clinical practice. Results showed that at 12 months patients on Actonel had a 43% (p=0.01) lower incidence of hip fractures compared to patients on alendronate. At 6 months similar results were seen, with Actonel resulting in a 46% (p=0.02) greater reduction in risk of hip fracture versus alendronate. The two treatments were not compared on the basis of side effects in this study.

"In osteoporosis, it is unlikely that prospective, head-to-head clinical fracture trials will be conducted due to the large number of patients required to show a difference between two effective therapies," said Professor Delmas, REAL study author, Universit, Claude Bernard, Lyon. "Large, comparative, retrospective analyses, like the REAL study, are one way to fill the knowledge gap and should be considered in the total body of evidence for a drug to optimise treatment decisions and enhance patient care."