Poor adherence to chronic medications is common and compromises medication effectiveness. We sought to describe longitudinal patterns of osteoporosis medication use.
This was a retrospective observational cohort study using 2005–2009 data from a large, commercially insured population.
Patients were women aged ≥55 years initiating osteoporosis therapy who had a ≥12-month (baseline) period with no osteoporosis therapy claims preceding initiation, and ≥24 months follow-up after therapy initiation. Discontinuation was defined as a gap >60 days (varied in sensitivity analyses) in prescription claims. Reinitiation was defined as a prescription claim for the same or different osteoporosis therapy following the therapy gap. Discontinuation and reinitiation patterns were described using Kaplan–Meier analysis. Multivariable Cox regression assessed the impact of baseline factors on reinitiation.
Of the 92,839 patients, 45%, 58%, and 70% discontinued therapy at 6, 12, and 24 months, respectively, following initiation. Of the discontinuers, 46% reinitiated therapy, with the majority doing so within 6 months of discontinuation. Women were less likely to reinitiate therapy if they were older (P < 0.0001) or were hospitalized during baseline (P = 0.0007). Women who discontinued treatment early (<6 months) following initiation were less likely to reinitiate (P < 0.0001) and remained on therapy for shorter periods following reinitiation. Depending on the available observation time, the median time on therapy following reinitiation was 58–193 days. Study findings did not change appreciably in sensitivity analyses.
Many patients stop and restart treatment for osteoporosis. A better understanding of determinants of treatment stopping and restarting could inform adherence improvement efforts.