A novel metric of autoimmune disease burden and its estimated incidence across different stages in life cycle of women.

AIM: To produce a unique metric 'autoimmune disease (ADs)' based on various single autoimmune disorder and estimate its case number and age-standardized rate of incidence for each stage in life cycle of women from 1990 to 2019, and to further explore their temporal trends at global, regional, and national levels.

METHODS

A comprehensive classification for life cycle of women was proposed. The estimates and 95 % uncertainty intervals (UIs) for case number and rate of incidence for rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, psoriasis, and type 1 diabetes mellitus in all age groups (< 1, 1-4, 5-9, 10-14, 15-19, 20-24, 25-29, ……,80-84, 85-89, 90-94, 95+) were extracted from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. 'ADs' was defined by combining these five disorders. Age standardization by direct method was utilized to estimate the age-standardized rate (ASR) of incidence of 'ADs' for each stage in life cycle of women. Joinpoint regression analysis was adopted to investigate temporal trends of ASR from 1990 to 2019 by calculating annual percentage change (APC) and average APC (AAPC). Associations of incidence in 2019 and change in incidence from 1990 to 2019, with Socio-demographic Index (SDI) were also explored.

RESULTS

In 2019, global ASR of incidence of 'ADs' in childhood, adolescence, adulthood, senility, women of childbearing age, perimenopause, menopause, and sex mature adults at the best reproductive age were 45.46 (95 % CI: 36.40 to 55.09), 59.97(95 % CI:46.62 to 75.30), 104.45 (95 % CI: 84.55 to 127.79), 129.58 (95 % CI: 105.18 to 157.68), 89.51 (95 % CI: 71.94 to 110.35), 130.92 (95 % CI: 106.98 to 158.16), 132.94 (95 % CI: 108.76 to 160.90) and 85.78 (95 % CI: 68.72 to 106.37), respectively. Regionally, although ASR in eight life stages differed from distinct geographical areas, the top three highest ASR all occurred in Western Europe, Australasia, and High-income North America. From 1990 to 2019, global ASR in childhood (AAPC: -0.39, [95 % CI: -0.4 to -0.38], p < 0.001), adolescence (AAPC: -0.4, [95 % CI: -0.41 to -0.4], p < 0.001), adulthood (AAPC: -0.53, [95 % CI: -0.55 to -0.51], p < 0.001), senility (AAPC: -0.4, [95 % CI: -0.41 to -0.38], p < 0.001), women of childbearing age (AAPC: -0.53, [95 % CI: -0.55 to -0.5], p < 0.001), perimenopause (AAPC: -0.56, [95 % CI: -0.59 to -0.52], p < 0.001), menopause (AAPC: -0.56, [95 % CI: -0.59 to -0.53], p < 0.001), and sex mature adults at the best reproductive age (AAPC: -0.5, [95 % CI: -0.51 to -0.49], p < 0.001) all significantly decreased. Nationally, ASR and its temporal trends in eight life stages varied significantly across 204 countries and territories. Additionally, incidence in 2019 and change in incidence from 1990 to 2019 were positively correlated with SDI across nations.

CONCLUSIONS

Significant heterogeneities in incidence of autoimmune diseases across nations, with higher sociodemographic development level presenting higher burden, suggest that flexible health policy and targeted resource allocation tailored to sociodemographic status are crucial for each country.