To estimate the population-based prevalence and healthcare use for osteoarthritis (OA) by First Nations (FN) and non-First Nations (non-FN) in Alberta, Canada.
A cohort of adults with OA (≥ 2 physician claims in 2 yrs or 1 hospitalization with ICD-9-Clinical Modification code 715x or ICD-10-Canadian Adaptation code M15-19, 1993-2010) was defined with FN determination by premium payer status. Prevalence rates (2007/8) were estimated from the cohort and the population registered with the Alberta Health Care Insurance Plan. Rates of outpatient primary care and specialist visits (orthopedics, rheumatology, internal medicine), arthroplasty (hip and knee), and all-cause hospitalization were estimated.
OA prevalence in FN was twice that of the non-FN population [16.1 vs 7.8 cases/100 population, standardized rate ratio (SRR) adjusted for age and sex 2.06, 95% CI 2.00-2.12]. The SRR (adjusted for age, sex, and location of residence) for primary care visits for OA was nearly double in FN compared with non-FN (SRR 1.88, 95% CI 1.87-1.89), and internal medicine visits were increased (SRR 1.25, 95% CI 1.25-1.26). Visit rates with an orthopedic surgeon (SRR 0.49, 95% CI 0.48-0.50) or rheumatologist (SRR 0.62, 95% CI 0.62-0.63) were substantially lower in FN with OA. Hip and knee arthroplasties were performed less frequently in FN with OA (SRR 0.48, 95% CI 0.47-0.49), but all-cause hospitalization rates were higher (SRR 1.59, 95% CI 1.58-1.60).
We estimate a 2-fold higher prevalence of OA in the FN population with differential healthcare use. Reasons for higher use of primary care and lower use of specialty services and arthroplasty compared with the general population are not yet understood.