To estimate prevalence of rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic disease (PsD), and crystal-related arthritis and health care use for inflammatory arthritis in First Nations and non-First Nations patients in Alberta, Canada.
Population-based cohorts of adults with RA, AS, PsD, and crystal-related arthritis were defined, with First Nations determination by premium payer status, to estimate prevalence rates. Rates of outpatient primary care, specialist visits, and hospitalizations (all-cause, inflammatory-arthritis specific) were estimated.
RA affected 3 times as many First Nations residents compared to non-First Nations residents (standardized rate ratio [SRR] 3.2, 95% confidence interval [95% CI] 2.9-3.4). AS and PsD were more prevalent in First Nations (AS 0.6 per 100 residents; SRR 2.7, 95% CI 2.3-3.2 and PsD 0.3 per 100 residents; SRR 1.5, 95% CI 1.3-1.9), whereas crystal-related arthritis was less prevalent (SRR 0.7, 95% CI 0.6-0.7). First Nations patients were more likely to have primary care visits (SRR 1.7, 95% CI 1.6-1.8) and less likely to have specialist visits (SRR 0.6, 95% CI 0.6-0.7) for RA relative to non-First Nations individuals. In PsD and crystal-related arthritis, First Nations people had higher rates of cause-specific hospitalizations.
The estimated prevalence of RA, AS, and PsD was higher in the First Nations population, while crystal-related arthritis was less prevalent compared to the non-First Nations population. First Nations people were more likely to see primary care physicians and were less likely to see specialists for inflammatory arthritis care.