This study estimated the status of early rheumatoid arthritis(RA) and gout in China, Japan, South Korea, North Korea and Mongolia from 1990 to 2021 and analyzed the disparities.

We calculated the numbers and age-standardized rates(ASRs) of prevalence, incidence and disability-adjusted life years(DALYs). Age-period-cohort(APC) analysis and time series models were employed to measure the burden trends of diseases. Frontier analysis were used to discuss differences in health potential among countries. Eight machine learning time series models were employed to forecast the future burden trends.

China had the highest burden numbers of diseases among five countries in 2021 (e.g. gout prevalence cases reaching 1,434,359.2, incidence cases of 363,759.3 and DALYs cases of 48,394.2). From 1990 to 2021, North Korea’s ASRs for gout (e.g., ASPR of 283.1 per 100,000 in 2021) and China’s ASRs for RA (e.g., ASDR of 20.9 per 100,000 in 2021) had consistently topped. There was an absolute predominance of male ASRs in the gout population of the same age group, while the opposite was true for RA. APC analysis revealed that ASRs of both diseases increased with age and later birth cohorts. Machine learning forecasts indicated fluctuating rises by 2050, for instance, Prophet model predicted China’s gout ASDR would rise to 9.3 per 100,000 (95% UI: 8.8–9.7) by 2025, while ARIMA model suggested China’s RA ASPR would peak at 131.9 per 100,000 (95% UI: 128.1–135.8). ARIMA model was the best solution for predicting ASPR in China and ASIR in Japan, while Prophet was more appropriate for the rest indicators.

In conclusion, our study demonstrated that early disease burdens of AA (RA and gout) were on the rising trends in the five East Asian countries and increased with age. The differences between men and women were in line with previous epidemiologic consensus. Trends and progression of rheumatic diseases in East Asia will become more prevalent in the next 30 years or so. East Asian region is ethnically homogeneous and faces the same pressures for diseases prevention and control, requiring the establishment of effective co-management measures.