Background/Purpose: Self-reported survey data and a single provincial administrative data source have previously indicated that the First Nations (FN) population in Canada has a 1.5 fold higher prevalence of osteoarthritis (OA), but the health services use by this population is unknown. Our objective was to determine whether OA prevalence and healthcare use in Alberta, Canada varies by FN status.

Methods: Using population-based healthcare administrative data (years 1993 to 2010), we defined a cohort of patients with OA (2 physician claims within 2 years or 1 hospitalization with diagnosis code ICD9 715x, or ICD10 M15-19). FN patients were identified based on premium payer status and represent 3.8% of the Alberta population. OA prevalence (fiscal year 2007/2008) and outpatient visits for OA to primary care physicians, specialists (orthopedic surgeons and rheumatologists), and arthroplasty (hip or knee) are reported for FN and non-FN populations.

Results: The age and sex standardized OA prevalence in FN Albertans is twice that of the non-FN population (161.0 vs 78.2 cases/1,000 population, standardized rate ratio 2.06; 95%CI 2.00-2.12). Prevalence is highest in people residing in rural locations and in females (Table 1).

Per year, FN persons had a mean of 3.4 primary care outpatient visits specifically for OA (20.3% of FN total primary care contacts) compared to 1.6 visits per year for non-FN persons (14.4% of non-FN total primary care contacts) (p<0.001). Contact with specialists was significantly lower for FN persons, with one-third fewer outpatient visits to orthopedics and rheumatology compared to non-FN persons (Table 2).

FN with OA were two-thirds less likely to have arthroplasty of the hip or knee. This did not appear to be driven by the presence of other medical comorbidities (Table 3).

Conclusion: We demonstrate disparities in OA care in FN persons given an estimated 2-fold higher disease prevalence from administrative data sources. While this finding may be driven in part by an increased probability of diagnosis through frequent primary care contact, it is unlikely to account for the large gap in use of specialty services and arthroplasty in FN compared to non-FN persons. This care gap may be due to access barriers for FN patients.