Economic burden of osteoarthritis - multi-country estimates of direct and indirect costs from the BISCUITS study.

Data from 'BISCUITS', a large Nordic cohort study linking several registries, were used to estimate differences in average direct and indirect costs between patients with osteoarthritis and controls (matched 1:1 based on birth year and sex) from the general population in Sweden, Norway, Finland and Denmark for 2017. Patients ≥18 years with ≥1 diagnosis of osteoarthritis (ICD-10: M15-M19) recorded in specialty or primary care (the latter available for a subset of patients in Sweden and for all patients in Finland) during 2011-2017 were included. Patients with a cancer diagnosis (ICD-10: C00-C43/C45-C97) were excluded. Productivity loss (sick leave and disability pension) and associated indirect costs were estimated among working-age adults (18-66 years). In 2017, average annual incremental direct costs among adults with osteoarthritis (n=1,157,236) in specialty care relative to controls ranged between €1,259 and €1,693 (p<0.001) per patient across all countries. Total average annual incremental costs were €3,224-€4,969 (p<0.001) per patient. Healthcare cost differences were mainly explained by osteoarthritis patients having more surgeries. However, among patients with both primary and secondary care data, primary care costs exceeded the costs of surgery. Primary care constituted 41 and 29 % of the difference in direct costs in Sweden and Finland, respectively. From a societal perspective, the total economic burden of osteoarthritis is substantial, and the incremental cost was estimated to €1.1-€1.3 billion yearly for patients in specialty care across the Nordic countries. When including patients in primary care, incremental costs rose to €3 billion in Sweden and €1.8 billion in Finland. Given the large economic impact, finding cost-effective and safe therapeutic strategies for these patients will be important.