Treatment pattern in postmenopausal women with osteoporosis: a population-based cohort study in South Korea

Introduction: The treatment landscape of postmenopausal osteoporosis (OP) in an Asian population is yet to be explored. Materials and methods: We conducted a retrospective cohort study to explore treatment patterns and characteristics associated with treatment interruption in postmenopausal women diagnosed with OP between 2008 and 2014. Treatment pattern assessment included the initial distribution of OP medications and treatment interruption rate according to the treatment groups during a 3-year follow-up period. We used multivariate logistic regression to estimate odds ratio (OR) and 95% confidence interval (CI) to identify factors associated with treatment interruption. Results: Of 21,813 patients, 87.9% initiated oral bisphosphonates (BP), followed by ibandronate intravenous (IV; 5.4%), selective estrogen receptor modulators (SERMs; 5.2%), pamidronate IV (1.4%) and zoledronic acid (0.06%). Treatment interruption was most notable in the first year of treatment, with cumulative treatment interruption rates highest for oral BP (76.3%) and lowest for pamidronate IV (50.5%). Compared to oral BP users, users of ibandronate IV (OR 0.34, 95% CI 0.30–0.39), pamidronate IV (0.49, 0.39–0.63), zoledronic acid (0.26, 0.09–0.77), and SERMs (0.50, 0.44–0.57) were less likely to interrupt treatment. Of characteristics assessed, presence of rheumatoid arthritis increased the odds of treatment interruption in ibandronate IV group (3.94, 2.12–7.33), and concomitant use of glucocorticoids for oral BP (1.11, 1.03–1.19) and pamidronate IV (2.04, 1.06–3.93) groups, respectively. Conclusion: Given the frequent treatment interruptions across all OP medications, our findings on the factors associated with treatment interruption will serve to implement targeted interventions in reinforcing persistence to OP treatment.