SummaryThis study estimated the direct medical costs of osteoporotic fractures from a large claim database in Japan. We further identified several comorbidities which drove the treatment costs. The results would contribute to health economic analysis as well as understanding of individual financial burden in Japan.IntroductionThe purposes of this study were to estimate treatment costs of osteoporotic fractures and to investigate the cost drivers.MethodsMale and female patients aged 50 years and older with a hip, vertebral, or non-hip/non-vert (NHNV) fracture between April 2008 and December 2016 were analyzed from claim database. Two types of costs were estimated. The incremental yearly costs of fractures and comorbidity treatments (total medical costs) were calculated by subtracting pre-fracture costs from post-fracture costs. The costs exclusive for fracture treatments (fracture treatment costs) were estimated by summing up the costs of fracture treatments within 1 year after fracture. The associations between comorbidities and costs were examined with a generalized linear model.ResultsTotal 12,898 patients were identified (83% was female). The total medical costs of fractures were $14,592 for male-hip, $15,691 for female-hip, $4268 for male-vertebral, $3819 for female-vertebral, $3790 for male-NHNV, and $4259 for female-NHNV. The fracture treatment costs were $4506 for male-hip, $5427 for female-hip, $1022 for male-vertebral, $1044 for female-vertebral, $1035 for male-NHNV, and $1408 for female NHNV. Three comorbidities were associated with increasing fracture treatment costs whereas four comorbidities were associated with decreasing fracture treatment costs. Five comorbidities were associated with increasing total medical costs whereas one comorbidity was associated with decreasing total medical costs.ConclusionsYearly treatment costs were increased considerably after fracture. Several comorbidities were considered to be cost drivers for osteoporotic fracture treatment. The cost estimates with different patient profile would support conducting health economic analysis in the future.