Rates and reasons for lack of persistence with anti-osteoporotic drugs: analysis of the Campania Region Database

Osteoporosis treatment involves several therapeutic tools, including long-term drug therapy. Subjects with chronic disorders are more likely to be non-adherent and/or non-persistent to treatment than those with other diseases. Adherence is the extent to which patients take medication as prescribed by their physicians, whereas persistence is the time from treatment initiation to discontinuation. Lack of persistence is common among subjects using oral anti-osteoporotic drugs, and leads to increased risk of fragility fracture. The aim of our study is to analyze the rates and reasons for discontinuation of anti-osteoporotic drugs in the Campania Region.The study was designed as a retrospective cohort study. Subjects aged over 40 years were included if they receive at least one prescription for any anti-osteoporotic drugs in 2009. Data were obtained from an administrative database of regional data on outpatient drug prescriptions reimbursed by the National Health Service (NHS). Patients were followed until the discontinuation of anti-osteoporotic therapy or until the end of the observation period (31st December 2010). A total of 30 048 were incident users of anti-osteoporotic drugs: 1731 (5.8%) males and 28???317 (94.2%) females. The mean age (S.D.) of the cohort was 69.0 (10.0) years. Weekly bisphosphonate (BP) (51.1%), was the most commonly prescribed drug. In the overall population, persistence rates were 34.8% after 6 months, 13.4% at 1 year. A multivariate Cox proportional hazard analysis showed that daily regimen (HR 1.9) treatments remained at a higher risk of early discontinuation compared to weekly regimen therapies. Patients who started treatment with a co-prescription with calcium and vitamin D had a lower risk of early discontinuation (HR 0.7). Our data showed that the persistence to osteoporosis therapy is significantly worse than reported in literature. A better osteoporosis management should include drugs with less frequent dosing, to obtain both an increase in rate of persistence and a reduction in side-effect.