To provide the level and trends of prevalence, incidence and disability adjusted life years (DALYs) for rheumatoid arthritis (RA) in 195 countries from 1990 to 2017 by age, sex, Socio-demographic Index (SDI; a composite of sociodemographic factors) and Healthcare Access and Quality (an indicator of health system performance) Index.
Data from the Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2017 were used. GBD 2017 modelled the burden of RA for 195 countries from 1990 to 2017, through a systematic analysis of mortality and morbidity data to estimate prevalence, incidence and DALYs. All estimates were presented as counts and age-standardised rates per 100 000 population, with uncertainty intervals (UIs).
Globally, the age-standardised point prevalence and annual incidence rates of RA were 246.6 (95% UI 222.4 to 270.8) and 14.9 (95% UI 13.3 to 16.4) in 2017, which increased by 7.4% (95% UI 5.3 to 9.4) and 8.2% (95% UI 5.9 to 10.5) from 1990, respectively. However, the age-standardised rate of RA DALYs per 100 000 population was 43.3 (95% UI 33.0 to 54.5) in 2017, which was a 3.6% (95% UI -9.7 to 0.3) decrease from the 1990 rate. The age-standardised prevalence and DALY rates increased with age and were higher in females; the rates peaked at 70-74 and 75-79 age groups for females and males, respectively. A non-linear association was found between age-standardised DALY rate and SDI. The global age-standardised DALY rate decreased from 1990 to 2012 but then increased and reached higher than expected levels in the following 5 years to 2017. The UK had the highest age-standardised prevalence rate (471.8 (95% UI 428.9 to 514.9)) and age-standardised incidence rate (27.5 (95% UI 24.7 to 30.0)) in 2017. Canada, Paraguay and Guatemala showed the largest increases in age-standardised prevalence rates (54.7% (95% UI 49.2 to 59.7), 41.8% (95% UI 35.0 to 48.6) and 37.0% (95% UI 30.9 to 43.9), respectively) and age-standardised incidence rates (48.2% (95% UI 41.5 to 55.1), 43.6% (95% UI 36.6 to 50.7) and 36.8% (95% UI 30.4 to 44.3), respectively) between 1990 and 2017.
RA is a major global public health challenge. The age-standardised prevalence and incidence rates are increasing, especially in countries such as Canada, Paraguay and Guatemala. Early identification and treatment of RA is vital especially among females, in order to reduce the ongoing burden of this condition. The quality of health data needs to be improved for better monitoring of disease burden.