OBJECTIVES: Osteoporosis patients face significant burden of illness due to subsequent fracture, but real-world studies are scarce. Thus, we aimed to assess the economic burden of subsequent fracture in South Korea.

METHODS: We conducted retrospective cohort analysis of national health insurance claims data. Study subjects included male and female osteoporosis patients of age ≥50 with incident fracture between 7/1/2014 and 7/1/2015. Subsequent fracture was defined as a fracture occurring within two years from incident fracture at a different site or at the same site after 6-months of the washout period. We evaluated fracture-related 1-year healthcare cost after incident fracture for patients with and without subsequent fracture. Per-patient-per-month (PPPM) cost was calculated by dividing each patient’s 1-year cost with time-to-subsequent-fracture. For the patients without subsequent fracture, PPPM cost equaled to 1-year monthly cost. We conducted generalized linear model (GLM) to estimate the ratio of increase and its 95% confidence interval (CI) in healthcare cost to assess the impact of subsequent fracture on healthcare cost.

RESULTS: A total of 73,717 osteoporosis patients with incident fracture were identified, consisting 38,401 (52.1%) vertebrae, 1,383 (1.9%) hip, and 33,933 (46.0%) non-vertebrae-non-hip (NVNH) fractures. Subsequent fracture occurred in 17.9% patients (35.9% vertebrae, 3.9% hip, 60.2% NVNH), with average time-to-subsequent-fracture of 256 days. The patients with subsequent fracture had significantly higher 1-year healthcare cost after incident fracture than the patients without subsequent fracture ($4,307 vs. $1,721) and the difference was greater in PPPM cost ($930 vs. $141). The GLM analysis showed that having subsequent fracture increased both 1-year healthcare cost after incident fracture and PPPM cost by 1.91-fold (95% CI 1.87-1.95) and 6.14-fold (95% CI 5.99-6.28), respectively.

CONCLUSIONS: Subsequent fracture imposes a substantial burden on osteoporosis patients with two-fold annual and six-fold PPPM increase of healthcare cost. More efforts are needed for preventing subsequent fracture among osteoporosis patients.