Geographic variation in incidence and prevalence rates for rheumatoid arthritis in Saskatchewan, Canada 2001-2014

To estimate and compare incidence/prevalence of rheumatoid arthritis (RA) in different geographic health regions and between urban/rural locations of residence within the province of Saskatchewan.

Saskatchewan Provincial Administrative Health Databases (2001-2014) were utilized as data sources. Two RA case-definitions were employed: (1) three physician billing diagnoses, at least one of which was submitted by a specialist (rheumatologist, general internist, or orthopedic surgeon) within 2 years; (2) one hospitalization diagnosis (ICD-9-CM code-714 and ICD-10-CA codes-M05, M06). Data from these definitions were combined to estimate annual RA incidence and prevalence. Annual incidence and prevalence rates across geographic regions and between rural and urban residences were examined.

An increasing RA prevalence gradient was observed in a south to north direction within the province. In the 2014-2015 Fiscal Year, the southern region of Sun Country had a 0.57% RA prevalence and the Northern Health Regions a prevalence of 1.15%. Incidence rates fluctuated over time in all regions but tended to be higher in Northern Health Regions. A higher RA prevalence trend was observed in rural residents over the study period.

Higher prevalence rates were observed for RA in Northern Health Regions than elsewhere in the province. Rural prevalence rates were higher than for urban residents. Healthcare delivery strategic planning will need to ensure appropriate access for RA patients throughout the province.