[Analysis and prediction of the age-period-cohort model of disease burden of rheumatoid arthritis in China from 1990 to 2019].

Using the Global Burden of Disease Study 2019 (GBD 2019) database, the Joinpoint regression model was used to analyze the trend of rheumatoid arthritis (RA) incidence and the standardized disability-adjusted life years (DALY) rate in China. The age, period, and cohort effects were discussed based on the age-period-cohort model. The grey prediction model GM (1, 1) was used to fit the trend of incidence and the standardized DALY rate of RA and predict the incidence and standardized DALY rate of RA in China from 2020 to 2034. From 1990 to 2019, the incidence, standardized incidence, and standardized DALY rate of RA showed a gradual upward trend, with an average annual increase of 1.41% (95% 1.32%-1.44%, <0.001); 0.10% (95% 0.01%-0.14%, <0.001); and 1.91% (95% 1.82%-2.12%, <0.001). The results of the age-period-cohort model showed that the longitudinal age curve of the incidence of RA from 1990 to 2019 showed a trend of increasing first and then decreasing, reaching a peak in the 60-64 years age group. The longitudinal age curve of the standardized DALY rate showed a gradual upward trend, reaching the peak in the 85-89 years age group. The results of period effect showed that the risk of RA increased first and then decreased from 1990 to 2019, with the highest risk from 2010 to 2014, and the risk of incidence was =1.03 (95% 1.00-1.06). The risk of DALY showed a fluctuating change, with a trend of decreasing first, then increasing, and then decreasing again. The highest risk of DALY in 2005-2009 period was =1.03 (95% 1.02-1.05). The results of the cohort effect showed that the later the birth, the higher the risk of morbidity and DALY. From 2020 to 2034, the projected incidence and standardized DALY rate of RA in China showed an upward trend. RA remains a major public health challenge. From 1990 to 2019, the incidence, standardized incidence, and standardized DALY rate of RA in China showed an increasing trend, which were affected by age, period effect, and cohort effect to varying degrees. Although the burden of RA in China is lower than the global average, it is still essential to take active preventive measures to reduce the burden of RA and identify and treat RA early.