The objective of this study was to evaluate persistence with denosumab among postmenopausal women with osteoporosis participating in the Canadian patient-support program (ProVital). Denosumab is an injectable therapeutic option for osteoporosis that is administered subcutaneously every 6 months.

ProVital, a support program in which patients voluntarily enroll, provides next injection reminder calls and educational material. A retrospective database analysis of patient self-reported data was conducted among osteoporotic women aged ≥50 who enrolled in the ProVital program and received their first denosumab injection between August 2010 and June 2011. To achieve 12 month persistence patients had to receive at least two denosumab injections, and to achieve 24 month persistence patients had to receive at least four denosumab injections, with consecutive injections no more than 6 months + 8 weeks apart. Logistic regression analysis was used to identify predictors of persistence.

A total of 1676 patients (mean age 74 years) were included. The 12 month persistence with denosumab was 81.6% (1367/1676 patients), and the 24 month persistence was 59.1% (991/1676 patients). Characteristics associated with both 12 and 24 month persistence were possession of private medication insurance and residence in Quebec. Additionally, age greater than 75, previous postmenopausal osteoporosis medication use, and fracture were associated with 24 month persistence.

Patient enrollment in the program was voluntary, so there may be selection bias for the patient population included in this study. Also, this study did not have a control group of patients who were not enrolled in a patient support program.

The persistence with denosumab among patients enrolled in the program was higher than historical persistence with oral bisphosphonates, and similar to persistence of patients in an education program taking teriparatide, patients taking bisphosphonates in a pharmaceutical care program, and two observational studies of denosumab.