Mortality and causes of death in inflammatory arthritis patients in Hong Kong 1997-2016

Abstract

Introduction: Inflammatory arthritis patients have a higher mortality than the general population due to increased risks of cardiovascular diseases, infection, and cancer. Survival of these patients has improved significantly over the past decades due to improvement in treatment and complications. However, it is unknown if the survival of these patients in Hong Kong has also improved. Methods: Patients with a diagnosis of rheumatoid arthritis (RA), psoriatic arthritis (PsA), or ankylosing spondylitis (AS) from 1997 to 2016 were identified in the Clinical Data Analysis and Reporting System (CDARS). Patient demographics and causes of death were obtained from CDARS. Results were analysed using R version 3.4.3 with package 'epitools' version 0.5-10. Mortality rate and standardised mortality ratio (SMR) were estimated every 5 years. Age and sex adjustment was conducted using census statistics from the Census and Statistics Department. A linear Poisson regression analysis was performed to evaluate the change in SMR over time. Results: In all, 15 445, 2165 and 4488 patients with RA, PsA and AS were included in this analysis, respectively. The SMR of RA, PsA and AS dropped significantly over 20 years. There was a significant decrease in cardiovascular death in patients with RA and AS (P<0.001). However, infection remained the leading cause of death in the last 20 years. Conclusion: Mortality in patients with inflammatory arthritis in Hong Kong has decreased significantly over the past 20 years.