A Cochrane review included 7 studies with a total of 14 049 women. Risk estimates for primary prevention were available only for vertebral and non vertebral fractures and showed no statistically significant effect of risedronate on fractures. For secondary prevention, a significant reduction in vertebral fractures (RR 0.61, 95% CI 0.50 to 0.76) with 5% absolute risk reduction (ARR) was found. There were significant reductions also for non-vertebral (RR 0.80, 95% CI 0.72 to 0.90; ARR 2%) and for hip fractures (RR 0.74, 95% CI 0.59 to 0.94; ARR 1%). When primary and secondary prevention studies were combined, the reduction in fractures remained statistically significant for both vertebral (RR 0.63, 0.51 to 0.77) and non vertebral fractures (RR 0.80, 0.72 to 0.90)
For adverse events, no statistically significant differences were found in any of the included studies. However, observational data has led to concerns regarding the potential risk for upper gastrointestinal injury and, less commonly, osteonecrosis of the jaw.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment and more than 20% loss to follow up).
The following decision support rules contain links to this evidence summary: