Build better bones with exercise (B3E pilot trial): results of a feasibility study of a multicenter randomized controlled trial of 12 months of home exercise in older women with vertebral fracture

This is a post-peer-review, pre-copyedit version of an article published in Osteoporosis International. The final authenticated version is available online at: https://doi.org/10.1007/s00198-018-4652-0 Summary We pilot-tested a trial of home exercise on individuals with osteoporosis and spine fracture. Our target enrollment was met, though it took longer than expected. Participants stayed in the study and completed the exercise program with no safety concerns. Future trials should expand the inclusion criteria and consider other changes. Purpose Osteoporotic fragility fractures create a substantial human and economic burden. There have been calls for a large randomized controlled trial examining the effect of exercise on fracture incidence. The B3E pilot trial was designed to evaluate the feasibility of a large trial examining the effects of home exercise on individuals at high risk of fracture. Methods Community-dwelling women ≥ 65 years with radiographically confirmed vertebral compression fractures were recruited at seven sites in Canada and Australia. We randomized participants in a 1:1 ratio to a 12-month home exercise program or equal attention control group, both delivered by a physiotherapist (PT). Participants received six PT home visits in addition to monthly phone calls from the PT and a blinded research assistant. The primary feasibility outcomes of the study were recruitment rate (20 per site in 1 year), retention rate (75% completion), and intervention adherence rate (60% of weeks meeting exercise goals). Secondary outcomes included falls, fractures and adverse events. Results One hundred forty-one participants were recruited; an average of 20 per site, though most sites took longer than anticipated. Retention and adherence met the criteria for success: 92% of participants completed the study; average adherence was 66%. The intervention group did not differ significantly in the number of falls (IRR 0.97, 95% CI 0.58 to 1.63) or fragility fractures (OR 1.11, 95% CI 0.60 to 2.05) compared to the control group. There were 18 serious adverse events in the intervention group and 12 in the control group. Conclusion An RCT of home exercise in women with vertebral fractures is feasible but recruitment was a challenge. Suggestions are made for the conduct of future trials. The research was funded by a CIHR Operating grant (MOP: 123445). Dr. Giangregorio received funding from an Ontario Ministry of Health Research and Innovation- Early Researcher Award