OBJECTIVES: Oral antiresorptive therapies (OART) can reduce the incidence of fragility fractures. However, half the patients discontinue OART after one year and adherence is poor. A Fracture Liaison Service (FLS) could optimize these parameters. We aimed to describe persistence and adherence to OART after 24 months in a FLS.

METHODS: A multidisciplinary FLS cohort study was conducted in two hospitals in Montreal, Canada. Fragility fracture patients (men and women) ≥40 years old were prospectively recruited. Patients were investigated for bone fragility and OART was prescribed if applicable. Patients were followed over two years. The date of cohort entry was a few days after the fracture (following consent). Using pharmacy claims data, persistence rate was defined by allowing a 30-day lag period for renewal and censoring switch to non-oral ART, hospitalizations, deaths and end of insurance coverage. The cumulative persistence rate was estimated using a Kaplan-Meier analysis. Drug adherence was measured by calculating the medication possession ratio (MPR).

RESULTS: Of 535 enrolled patients, 85.6% were women. Mean age was 63.4±11.2 years. One hundred thirty-nine patients (26%) had at least one prescription for an anti-osteoporosis medication delivered before cohort entry. The cumulative persistence rates after one and two years were 77.8% and 65.9%, respectively. The difference between the cumulative persistence rates of experienced and new users was not significant (71.0% vs 63.2%, p=0.144). Median MPR after two years was 53.9% (22.6-85.7%), where 31.5% had a MPR>80%. The median MPR over the year before the fracture was 36.5% (0.3-74%). Median MPR in persistent and non-persistent patients were 69.4% (33.7-91.0%) and 28.2% (9.7-60.7%), respectively (p<0.001).

CONCLUSIONS: Our intervention led to an increase in persistence to treatment compared to usual care. Despite adherence remaining suboptimal, it was improved in persistent patients. Adjusted analyses will follow to identify determinants of OART persistence and adherence in our cohort.