Effect of monitoring bone turnover markers on persistence with risedronate treatment of postmenopausal osteoporosis.

Abstract

Persistence with osteoporosis treatment is poor but is important for maximum benefit. The objective of the study was to assess the impact of physician reinforcement using bone turnover markers (BTMs) on persistence with risedronate treatment. This was a 1-yr multinational prospective, open-label, blinded study in 171 osteoporosis centers in 21 countries. A total of 2382 postmenopausal women (65-80 yr old) with spine/hip T-score -2.5 or less or T-score -1.0 or less with a low-trauma fracture. Intervention included calcium 500 mg/d, vitamin D 400 IU/d, and risedronate 5 mg/d for 1 yr. Centers were randomized to reinforcement (RE+) or no reinforcement (RE-). At 13 and 25 wk, reinforcement based on urinary N-telopeptide of type I collagen change from baseline was provided to the RE+ patients using the following response categories: good (>30% decrease), stable (-30% to +30% change), or poor (>30% increase). Persistence assessed with electronic drug monitors was measured. In the overall efficacy population (n=2302), persistence was unexpectedly high and was similar for both groups (RE-, 77%; RE+, 80%; P=0.160). A significant relationship between the type of message and persistence was observed (P=0.017). Compared with RE-, intervention based on a good BTM response was associated with a significant improvement in persistence [hazard ratio (HR) 0.71; 95% confidence interval (CI) 0.53-0.95]. Persistence was unchanged (HR 1.02; 95% CI 0.74-1.40) or lower (HR 2.22; 95% CI 1.27-3.89) when reinforcement was based on a stable or poor BTM response, respectively. Reinforcement was associated with a lower incidence of new radiologically determined vertebral fractures (odds ratio 0.4; 95% CI, 0.2-1.0). Reinforcement using BTMs influences persistence with treatment in postmenopausal women with osteoporosis, depending on the BTM response observed.