Persistence and compliance to osteoporosis therapy in a fracture liaison service: a prospective cohort study

Abstract

Persistence and compliance to osteoporosis medications aiming to prevent fragility fractures are essential for fracture prevention, but are suboptimal in the population. A Fracture Liaison Service with a systematic follow-up led to ongoing therapy and optimal drug compliance for more than half of treated patients over 2 years.

Purpose: Fracture Liaison Services (FLS) have the potential to improve persistence and compliance to osteoporosis therapy. We aimed to assess patterns of drug use in a high-level intervention FLS.

Methods: Women and men (> 40 years) with a fragility fracture were recruited in a FLS, where osteoporosis therapy was prescribed if appropriate. Based on claims data, patients who filled their prescription in the 3-month period following baseline were selected. The 1- and 2-year persistence rates were measured using survival analysis. In non-persistent subjects, 1-year treatment re-initiation was measured. The 1- and 2-year compliance levels were measured, using the proportion of days covered (PDC > 80% = compliant). Regression analyses were performed to identify predictors of non-persistence/compliance.

Results: Out of 332 subjects with complete drug insurance coverage, 297 (89.5%) were prescribed osteoporosis therapy by the FLS, and 275 (92.6%) were dispensed. Two hundred sixty participants (86.9% female; mean age 65.6 years) were selected for having filled a prescription inside 3 months after baseline. The 1- and 2-year persistence rates were 66.4% and 55.6%, respectively. Treatment re-initiation was observed in 56% of non-persistent patients. PDC was > 80% in 64.2% for 1 year and 62.5% for 2 years. Older and younger age, smoking, higher spine bone mineral density, lower major FRAX risk, and missing follow-up visits were predictors of non-persistence and/or non-compliance.

Conclusions: After 2 years in a high-level intervention FLS, more than half the treated participants were persistent and compliant to treatment. Comparative effectiveness studies must be undertaken to determine whether this intervention is an improvement over usual care.

Keywords: Compliance; Fracture liaison service; Fragility fracture; Osteoporosis; Persistence.