Hospital Admissions for Patients with Rheumatoid Arthritis in Western Australia Hospitals Have Declined Significantly Over Time (1995-2014)

Abstract

Introduction
Rheumatoid arthritis (RA) imposes a considerable burden on society in terms of morbidity, long-term disability, and costs. RA prevalence is poorly described in Australia, and linked health datasets can provide a more meaningful picture for RA epidemiology in the Australian population.

Objectives and Approach
We extracted data on all patients identified in the WA Hospital Morbidity Data Collection between 1995 and 2014, with the International Classification of Diseases (ICD) codes for RA (ICD 10 M05.00–M06.99, and the corresponding ICD 9 codes). We estimated RA point- and period prevalence rates per 1000 hospital separations and annual average percentage changes, with the total number of hospital separations each year obtained from the Australian Institute of Health and Welfare, which served as the denominator.

Results
A total of 17,125 patients were admitted to WA hospitals with a diagnostic code for RA over the study period (1995-2014). The total number of hospital separations for RA patients was 50,353, indicating an average of three hospital separations per patient over twenty years. The RA prevalence was 3.4 per 1000 separations over the study period, with a -2.89% annual average decrease since 1995.The RA point prevalence remained constant in the early part of the study period, at 7.9 per 1000 separations, then decreased in the later years, from 3 per 1000 separations in 2009 to 1.9 per 1000 separations in 2014.

Conclusion / Implications
These data demonstrate that hospitalisation for RA has decreased considerably in WA over the last two decades. As this decrease roughly coincides with the introduction of biological drug treatment for RA, the reduced need for hospital admission is likely due to improvements in RA management.