The prevalence of rheumatoid arthritis in Western Australia

Abstract

Background Rheumatoid arthritis (RA) is the most common form of autoimmune arthritis, but the prevalence in Australia is unknown. We estimated RA period prevalence and identified factors associated with frequent RA hospitalisations, using linked administrative health and state-specific Australian Pharmaceutical Benefits Scheme (PBS) datasets in Western Australia (WA) from 1995 to 2014. Methods This was a longitudinal population-based cohort study using two independent datasets to identify prevalent RA patients. RA prevalence was calculated per 1000 hospital separations and biological therapy users. RA patients were identified in the WA linked health dataset using ICD codes 714.0–714.9 and M05.00–M06.99. Dispensing data on biological therapy for RA were obtained from PBS records and converted to defined daily doses /1000 population/day. Multivariable logistic regression was used to analyse factors associated with frequent RA hospitalisations (> 2/year), controlling for sex, age, and geographic locations. Potential interactions were assessed using logistic regression in a stepwise approach. Results A total of 17,125 RA patients had 50,353 hospital separations between 1995 and 2014, averaging three hospitalisations per patient over 20 years. The RA period prevalence was 3.4 per 1000 separations (0.34%; 95% CI 0.33–0.34), while the RA period prevalence based on biological therapy use was 0.36% (95% CI 0.35–0.37). The corrected RA prevalence based on biological therapy usage was 0.36% (95% CI 0.35–0.37) for the 2005–2009 and increased to 0.72% (95% CI 0.70–0.74) in 2010–2014 period. Associated factors for frequent RA hospitalisations were being female [1.21 (95% CI 1.15–1.26)], aged 60–69 years [4.45 (95% CI 3.74–5.30)], living in rural areas [1.12 (95% CI 1.02–1.24)]. The odd ratio of interaction between these associated factors was 1.34 (95% CI 1.16–1.55). Conclusion The minimal prevalence of RA in Western Australia is 0.34–0.36%, which falls within the literature range. Older female RA patients in rural were more likely to be hospitalised, suggesting unmet primary care for needs.

Comorbidities and extra-articular manifestations of Rheumatoid arthritis in sub-Saharian Africa

“…It is a disease that mainly affects women and a population of young adults in accordance with the results reported in the literature [24][25][26]. The lifestyle of patients was characterized by smoking in 2-13.6%.…”

Association of serum IL12 with clinical and biochemical parameters in a cohort of diagnosed rheumatoid arthritis patients on oral conventional synthetic disease modifying anti-rheumatic drugs

“…The prevalence of RA in Western Australia was observed to be 0.34-0.36% from 1995 till 2014. 2 The RA prevalence was reported to be 0.65% in Japan 3 and 0.69% in Spain 4 . The reported prevalence in Karachi, Pakistan, is 0.142% 5 .…”