Trends of autoimmune diseases in men and inequities in healthcare access and quality in young, working and postworking individuals: a global analysis of 32-year epidemiological study

Abstract

Introduction

Health issues regarding autoimmune diseases in men have been neglected. We here investigated temporal trends in burden of autoimmune diseases in men and assessed inequities in healthcare access and quality worldwide.

Methods

This ecological, descriptive time-series analysis using Global Burden of Disease estimates included men with autoimmune diseases at all ages covering 204 countries and territories from 1990 to 2021. Age-standardised rates of incidence, prevalence, mortality, disability-adjusted life-years (DALYs), years lived with disability (YLDs) and years of life lost (YLLs) and average annual percentage change were calculated. Global trends were stratified by age, sociodemographic index (SDI), region and country. Overall Quality of Care Index (QCI) and three selected age groups including young (aged 0–14 years), working (aged 15–64 years) and postworking (aged 65+ years) QCI were calculated globally, regionally and nationally.

Results

Globally, the burden of autoimmune diseases in men significantly decreased from 1990 to 2021. However, in high SDI countries, age-standardised incidence rate increased from 2005, and age-standardised prevalence and YLDs rates increased from 2015. In 2021, significant disparities in QCI scores persisted across SDI levels, with the overall QCI ranging from 74.97 in low–middle countries to 90.55 in high SDI countries. Remarkable ranges in QCI scores between low SDI countries and high SDI countries for the young, working and postworking groups were also detected, with estimates of 82.94 to 92.18, 74.76 to 89.59 and 68.18 to 85.78, respectively. Absolute convergence in QCI was estimated in all these three age groups, with the most prominent convergence in the young group.

Conclusions

Progress towards controlling autoimmune diseases in men varied widely, with substantially high mortality in low and low–middle SDI countries. Significant inequities in healthcare access and quality persisted across sociodemographic development levels and age groups. Healthcare systems need to improve healthcare access and quality for working and postworking populations while simultaneously maintaining performance among young individuals.

WHAT IS ALREADY KNOWN ON THIS TOPIC

• Autoimmune diseases are traditionally considered to be predominant in women, especially those of childbearing age.

• Global burden and secular trend of autoimmune diseases in men, and variations across different sociodemographic levels and geographic locations, have not been specifically investigated.

• Assessment on whether health systems provide access to quality healthcare for all ages in men with autoimmune diseases and its inequities is lacking, impeding universal health coverage.

WHAT THIS STUDY ADDS

• Burden of autoimmune disease in men significantly decreased from 1990 to 2021 globally; however, concomitant with clear upward trends in incidence (since 2005), prevalence (since 2015) and years lived with disability (since 2015) in countries with high sociodemographic index.

• Progress towards controlling autoimmunity varied widely across locations, with substantial mortality in countries with low and low–middle sociodemographic index.

• Prevailing inequities in healthcare access and quality persisted across sociodemographic levels, geographic locations and age groups, with encouraging prominent convergence in young group and concerning less convergence and lower performance for working and postworking populations.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• Autoimmune disease burden in men remains heavy. To achieve the universal health coverage of Targets of Sustainable Development Goal 3, it is necessary to give priority to improve healthcare access and quality among working and postworking populations, especially in low and low–middle sociodemographic development nations.

Introduction

Autoimmune diseases resulting from the failure of self-tolerance serve as a major global health concern. It is estimated that approximately 10% of the world’s population is affected by these conditions, and case number is predicted to continue rising.1,3 Most autoimmune diseases are considered as chronic disorders with a striking female predominance, especially in women of childbearing age, whereas are rarely seen in men.^{4 5} However, autoimmune diseases in men have become increasingly common, and increases in incidence of autoimmune diseases in men have been detected. For example, a systematic review covering literature from January 1988 to December 2005 found that the median gender-specific incidence rate of rheumatoid arthritis increased from 18 to 18.5 cases per 100 000 men.⁶

It is reported that women account for approximately 80% of all autoimmune disease cases, a disparity potentially linked to a molecular coating on the X chromosome.⁷ Due to this female predominance, previous research has primarily focused on women, informing gender-specific health policies and resource allocation.^{8 9} For instance, the book ‘Women’s Health in Autoimmune Diseases’ provides a comprehensive summary of updated clinical guidelines for treating and managing autoimmune diseases in women, especially under special circumstances such as pregnancy.¹⁰ However, health issues regarding autoimmune diseases in men have long been neglected and attention to men with autoimmune diseases is severely insufficient. Clinical guidelines derived largely from female populations may not be appropriate for men, potentially leading to suboptimal prevention and treatment outcomes. Global efforts to further attenuate such health inequity in men with autoimmune disease demand urgent action based on the understanding of the incidence, prevalence and mortality at regional and national levels.

Studies have reported on the burden, trend and sociodemographic index (SDI)-related health disparities in autoimmune diseases from 1990 to 2019 for both sexes,^{2 11} with a special focus on the women of childbearing age.¹² However, no study has specifically examined the global burden and secular trend of autoimmune diseases in men, and the variations among different geographic regions and countries with different socioeconomic development levels. Furthermore, assessment on whether health systems provide access to quality healthcare for all ages in men with autoimmune diseases and its health inequities is lacking, restricting the suitable provision of acceptable quality of care to these patients and impeding universal health coverage.

In this study, we aimed to provide more valuable information on these issues by analysing data from the Global Burden of Disease, Injuries and Risk Factors Study (GBD) 2021. We described global epidemiological patterns of autoimmune diseases in men and further explored secular trends and variations by several factors (SDI, age, region and country) from 1990 to 2021. We also evaluated the inequities in healthcare access and quality provided by health systems to men with autoimmune diseases overall and for three selected age groups (young, aged 0–14 years; working, aged 15–64 years; postworking, aged 65+ years) in 204 locations over the last 32 years, with a special focus on how much does healthcare access and quality vary across age and to what extent healthcare access and quality converge over time by age.

Materials and methods

Data source

GBD 2021 provided comprehensive estimation on the burden of 371 diseases and injuries and 88 risk factors, including autoimmune diseases, across 21 regions and 204 countries and territories from 1990 to 2021.^{13 14} Annual case and rate of incidence, prevalence, mortality, disability-adjusted life years (DALYs), years lived with disability (YLDs) and years of life lost (YLLs) of autoimmune diseases in men from 1990 to 2021, by age groups (<5 years, 5–9 years, 10–14 years, 15–19 years, 20–24 years, 25–29 years, 30–34 years, 35–39 years, 40–44 years, 45–49 years, 50–54 years, 55–59 tears, 60–64 years, 65–69 years, 70–74 years, 75–79 years, 80–84 years, 85–89 years, 90–94 years, 95+ years) and cause (rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, diabetes mellitus type 1, asthma and psoriasis) at global, regional and national levels were extracted from the Global Health Data Exchange query tool.¹⁵ SDI reported by GBD 2021 was used (details in online supplemental file 1, eMethod 1). This study followed the Strengthening Reporting of Observational Studies in Epidemiology (STROBE) guidelines.

Statistical analysis

This study aimed to analyse epidemiological patterns and secular trends of autoimmune diseases using age-standardised rate (ASR) and case. Since there were no published uncertainty intervals (UIs) for estimates of autoimmune diseases, we calculated 95% CIs based on the corresponding SEs, obtained by the width of 95% UIs divided by 1.96×2.¹⁶ ASR was calculated by standardisation based on the world standard population reported in the GBD 2021.¹⁷ Age standardisation method was used with the following equation^{12 18}:

$${\displaystyle {\displaystyle {\displaystyle \mathrm{A}\mathrm{g}\mathrm{e}\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{a}\mathrm{r}\mathrm{d}\mathrm{i}\mathrm{z}\mathrm{e}\mathrm{d}\mathrm{r}\mathrm{a}\mathrm{t}\mathrm{e}=\frac{\sum _{i=1}^A{a}_i{w}_i}{\sum _{i=1}^A{w}_i}}}}$$

where the ai is age-specific rate and the wi is weight in the same age subgroup of the chosen reference standard population and A is the upper age limit. To evaluate magnitude and direction of global temporal trends in incidence, prevalence, mortality, DALYs, YLDs and YLLs, average annual percentage change (AAPC) was calculated using the jointpoint regression model.¹⁹ Global trends were stratified by age and SDI subgroups. Regional and national trends were also investigated (details in online supplemental file 1, eMethod 2). Healthcare access and quality of men with autoimmune diseases were examined by calculating Quality of Care Index (QCI).²⁰ (Details in online supplemental file 1, eMethod 3.) According to the Organization for Economic Co-operation and Development (OECD) definition of the working age population (15–64 years),²¹ overall QCI was also grouped into young (aged 0–14 years), working (aged 15–64 years) and postworking (aged 65+ years) QCI. Groupings aimed to distinguish access to quality healthcare related to employment (for those aged 15–64 years), versus healthcare access and quality enabled by social health insurance coverage associated with ageing (for those aged 65 years and older) and from access to child healthcare and quality (for those aged 0–14 years).²² Joinpoint regression model was established in joinpoint regression programme (V.5.2.0), which was developed by the National Cancer Institute at the National Institutes of Health. Statistical analyses and visualisation were conducted in R software (V.4.2.1). Statistical significance was set at p<0.05 (two sided).

Patient and public involvement

The GBD, Injuries and Risk Factors Study is a collaborative scientific effort quantifying health loss across places and over time. Our present study utilised the secondary data from this collaborative work, and we did not have direct access to the participants. No patients were involved in setting research question, designing research protocols, implementing steps, analysing data, interpreting results or writing manuscript.

Results

Global distribution of autoimmune diseases in men in 2021

Globally, in 2021, age-standardised incidence, prevalence, mortality, DALYs, YLDs and YLLs rate per 100 000 were 605.66 (95% CI 382.36 to 916.95), 4179.74 (95% CI 3266.64 to 5363.69), 6.94 (95% CI 5.61 to 10.09), 402.13 (95% CI 304.24 to 559.84), 216.07 (95% CI 135.95 to 324.68) and 186.06 (95% CI 150.19 to 263.12), respectively. By SDI category, we found the highest age-standardised incidence, prevalence and YLDs rate in high SDI countries, and the highest DALYs and YLLs rate in low SDI countries. Countries with a low–middle SDI had the lowest incidence and prevalence rate but the highest mortality rate (figure 1, online supplemental file 2, eTable 1–6). Examination of age distribution indicated that older age groups (aged >65 years) generally had higher ASR in prevalence, mortality, DALYs, YLDs and YLLs, except in incidence where younger age groups (aged <14 years) had higher ASR. Moreover, for prevalence and YLDs, younger age groups also had high burden that were similar with older age groups (figure 2, online supplemental file 2, eTable 7–12).

Figure 1. Temporal trends of age standardised incidence, prevalence, mortality, DALYs, YLDs and YLLs rates for autoimmune diseases in men and their AAPC, globally and by SDI category from 1990 to 2021. The axes were displayed on a linear scale. AAPC, average annual percentage change; DALYs, disability-adjusted life-years; SDI, sociodemographic index; YLDs, years lived with disability; YLLs, years of life lost.

Figure 2. Global age-specific incidence, prevalence, mortality, DALYs, YLDs and YLLs rates for autoimmune diseases in men by age groups in 1990 and 2021, and their AAPC from 1990 to 2021. The axes were displayed on a linear scale. AAPC, average annual percentage change; DALYs, disability-adjusted life-years; YLDs, years lived with disability; YLLs, years of life lost.

Regionally, the greatest burden of autoimmune diseases in men was observed in high-income North America and Oceania (online supplemental file 2, eTable 1–6); nationally, burden of autoimmune diseases in men varied significantly, with the highest age-standardised incidence, prevalence, mortality, DALYs, YLDs and YLLs rate in Madagascar, Grenada, Syrian Arab Republic, Central African Republic, United States of America and Lesotho, respectively (figure 3, online supplemental file 2, eFigure 1–5).

Figure 3. Age standardised prevalence rate for autoimmune diseases in men in 2021 and its AAPC from 1990 to 2021 across 204 countries and territories. AAPC, average annual percentage change.

Temporal trend of autoimmune diseases in men from 1990 to 2021

Globally, from 1990 to 2021, age-standardised incidence, prevalence, mortality, DALYs, YLDs and YLLs rate significantly decreased, with an AAPC of −1.02 (95% CI −1.11 to −0.92), −1.29 (95% CI −1.39 to −1.2), −2.15 (95% CI −2.24 to −2.05), −1.57 (95% CI −1.63 to −1.5), −0.98 (95% CI −1.04 to −0.93) and −2.13 (95% CI −2.19 to −2.07), respectively. By SDI category, the burden of autoimmune diseases in men significantly decreased in all five categories. We found the fastest decrease in age-standardised incidence, prevalence and YLDs rate in low–middle SDI countries, the fastest decrease in DALYs rate in low SDI countries and the fastest decrease in mortality and YLLs rate in high–middle SDI countries (figure 1, online supplemental file 2, eTable 1–6). Examination of age distribution indicated that the burden of autoimmune diseases in men significantly decreased in all age groups, with relatively slighter descent rates in adolescents and young adults (aged 15–44 years). We found the fastest decrease in age-standardised incidence rate in old adults aged 65–69 years, the fastest decrease in prevalence and YLDs rate in old adults aged 75–79 years, and the fastest decrease in mortality, DALYs and YLLs rate in children aged 0–4 years (figure 2, online supplemental file 2, eTable 7–12).

Regionally, burden of autoimmune diseases in men significantly decreased in nearly all regions, with the fastest decrease in high-income Asia Pacific. However, increasing trends in incidence in Central Europe and prevalence in high-income North America as well as stable trends in incidence, DALYs and YLDs in high-income North America were detected (online supplemental file 2, eTable 1–6). Nationally, temporal trend in burden of autoimmune diseases in men varied significantly. Age-standardised prevalence rate increased in 8 countries, kept stable in 4 countries and decreased in 192 countries, with the largest decrease in Japan, followed by New Zealand and Singapore (figure 3). Age-standardised DALYs rate showed upward trends in 2 countries, stable trends in 5 countries and downward trends in 197 countries, with the largest decrease in Republic of Korea, followed by Maldives and Equatorial Guinea (online supplemental file 2, eFigure 3).

Inequities in healthcare access and quality towards autoimmune diseases in men

Overall QCI increased or very slightly decreased from 1990 to 2021 globally and in five categories of SDI, with a value of 85.37, 90.55, 88.86, 85.04, 74.97 and 77.19 for global level, high SDI, high–middle SDI, middle SDI, low–middle SDI and low SDI in 2021, respectively. When stratified by age groups, trends in young, working and postworking QCI from 1990 to 2021 globally and in five SDI categories were similar with that in overall QCI (figure 4).

Figure 4. Trends in QCI score for men with autoimmune diseases and change in gap in QCI score between high SDI quintile and other quintiles, overall and by select age groups from 1990 to 2021. The axes were displayed on a linear scale. QCI, Quality of Care Index; SDI, sociodemographic index.

For both overall population and each age group, the gap in QCI score between high SDI quintile and other SDI quintiles narrowed in 2021 compared with that in 1990, with the most progress observed in low SDI and low–middle SDI. From 1990 to 2021, the gap between high SDI and low SDI for overall, young and postworking QCI declined 4.63, 7.68 and 5.98, respectively, and the gap between high SDI and low–middle SDI for working QCI declined 6.76 (figure 4, online supplemental file 2, eTable 13). Among different age groups, young QCI was always higher than working QCI, which was always higher than postworking QCI, globally and in five SDI categories from 1990 to 2021 (figure 4). Moreover, cross-SDI inequities in QCI, that is, the difference between the highest QCI and the lowest QCI among five SDI quintiles in a given year, exacerbated with age and attenuated over time. From 1990 to 2021, cross-SDI inequity in young QCI decreased from 16.92 to 9.24, in working QCI decreased from 21.57 to 14.83, and in postworking QCI decreased from 23.59 to 17.60 (figure 5, online supplemental file 2, eTable 14).

Figure 5. Difference between the highest QCI score and the lowest QCI score across five SDI quintiles, overall and by select age groups from 1990 to 2021. QCI, Quality of Care Index; SDI, sociodemographic index.

Regionally, in 2021, Australasia (93.46) followed by Western Europe (93.13) and Southern Latin America (91.25) were the three regions with the highest overall QCI, whereas Oceania (60.13), Southern Sub-Saharan Africa (65.75) and South Asia (72.21) were on the other side of this spectrum. For the select age groups, Australasia, Western Europe and Southern Latin America were three regions with the highest values, whereas Oceania, Southern Sub-Saharan Africa and Central Sub-Saharan Africa were on the other side (online supplemental file 2, eTable 15). Nationally, in 2021, Portugal (96.19) was the best condition for overall QCI followed by Netherlands (95.98) and Luxembourg (95.92), whereas Lesotho (19.58), Zimbabwe (37.05) and Fiji (42.08) were countries with the poorest conditions. For young QCI, Netherlands, Australia and Ireland had the best conditions, whereas Lesotho, Niue and Tokelau had the poorest conditions. For working QCI, Portugal, Luxembourg and Australia were countries with the highest values, whereas Lesotho, Zimbabwe and Mali were countries with the lowest values. For postworking QCI, Monaco, Luxembourg and Portugal had the best conditions whereas Lesotho, Zimbabwe and Fiji were on the other side (online supplemental file 2, eTable 16).

Discussion

Principal findings

Our study revealed a global decline in the autoimmune disease burden among men from 1990 to 2021. However, high SDI countries exhibited upward trends in incidence (since 2005), prevalence (since 2015) and YLDs (since 2015). High SDI countries had the highest incidence and prevalence yet very low mortality, whereas low–middle SDI countries recorded the highest mortality despite the lowest incidence and prevalence. A ‘dumbbell-shaped’ age distribution emerged, with both older (>65 years) and younger men (<14 years) shouldering disproportionately higher disease burden. Although healthcare access and quality for men with autoimmune diseases in overall and selected age groups improved in most countries between 1990 and 2021, significant inequities across social and economic development levels, different locations and age groups persisted. Countries with lower SDI accessed poorer quality healthcare in overall and three selected age groups. Encouragingly, a convergence in healthcare access and quality was detected in all three age groups, most prominently among young individuals, who also demonstrated a better overall healthcare performance. In the context of global population structure transition, especially population ageing, less convergence and lower performance in healthcare access and quality in working and postworking populations suggested that alterations in healthcare systems lagged epidemiological changes and could have broader adverse social and economic consequences, including impaired benefit from demographic dividend, decreased national tax revenue, additional mortality among the elderly and exacerbated gender inequity in care-taking duties, etc.

Sociodemographic disparities

Disease burden and health outcome are tightly associated with the sociodemographic development status.^{13 17} Our findings also revealed substantial disparities in burden of autoimmune diseases among men across different SDI categories. In 2021, high SDI countries exhibited the highest incidence and prevalence rate, yet remarkably low mortality. This aligned with previous studies, which proposed that improved sociodemographic and economic status, leading to progressive depletion of microbes and parasites and reduction in infections could directly contribute to an increase in autoimmune diseases.^{23 24} Fortunately, patients in these countries often have better access to quality medical services including advanced therapy strategy and timely disease surveillance,²⁵ which likely helps reduce mortality. In contrast, low-middle SDI countries recorded the highest mortality despite having the lowest incidence and prevalence. This may be attributed to poorer quality of basic autoimmune disease care, including less access to effective medications in these countries.²⁶ Additionally, universal health coverage for non-communicable diseases including autoimmune diseases remains substantially underdeveloped compared with that for communicable and nutritional diseases in low–middle SDI countries,²⁷ indicating that health system reforms have not kept pace with epidemiological shifts. This misalignment may further exacerbate mortality. Notably, it is reported that socioeconomic change has been faster in countries with a lower SDI,²⁸ as a result, these countries may face similar conditions to high SDI countries in the coming decades. It is, therefore, crucial for countries undergoing rapid socioeconomic transition to proactively adapt their health systems by enhancing the availability, accessibility and affordability of efficient prevention, management and treatment programmes to meet evolving disease burden.

Age disparities

The burden of autoimmune diseases in men significantly decreased acorss all age subgroups from 1990 to 2021. This decline may be related to improved accessibility and coverage of medical healthcare services as well as achievements in economic growth, poverty reduction and social protection.²⁹ Although the most notable decreases occurred in the older and younger age groups from 1990 to 2021, these populations still carried a higher burden in 2021, indicating a ‘dumbbell-shaped’ distribution of disease burden. On the one hand, population ageing is accelerating globally, and the proportion of global population over 60 years would nearly double from 12% to 22% between 2015 and 2050, as reported by the WHO.³⁰ Autoimmune diseases in the elderly have unique clinical manifestations, and insidious and atypical symptoms may pose great challenges for the physician.³¹ On the other hand, health and well-being of children serve as an important engine driving positive changes in creating a more sustainable society, and investments into health management of children may bring not only benefits for themselves now but also for their future older adult lives. WHO has launched the Global Strategy for Women’s, Children’s and Adolescents’ Health (2016–2030) and established the Child Health and Development Unit to strengthen primary healthcare and achieve universal health coverage for all children.^{32 33} For children with autoimmune diseases, healthcare efforts should prioritise continuous monitoring of disease progression. Children with one autoimmune disease are more likely to develop another autoimmune disease and a host of other serious conditions, such as diabetes. Even low-grade inflammation during childhood can lead to significant health complications in adulthood.^{34 35}

Inequities in healthcare access and quality

The varying burden of autoimmune diseases in men underscores the urgent need for timely, adequate and efficient healthcare. Our results demonstrated improvements in overall and selected age group QCI for men with autoimmune diseases in most countries between 1990 and 2021, which was essential for the achievement of universal health coverage. However, substantial geographic disparities in QCI scores persisted. Countries with higher SDI performed better in QCI, with approximately 9–24 points separating the lowest and highest QCI scores among five SDI quintiles for overall and three selected age groups. High level of social and economic development could improve healthcare access and quality by enhancing the ability of health systems through a series of measures, including integrating more resources for health insurance, pooling more funds for health research, purchasing more advanced technology and equipment for health practice, and improving quality of medical staff, etc.²²

From a longitudinal perspective (1990–2021), for three selected age groups, gap in QCI scores with high SDI quintile narrowed or at least remained stable for all SDI levels, and countries with the poorest QCI performance have made progress in closing disparities with the highest QCI scores, together suggesting a convergence in QCI for these three groups over time, with the most prominent convergence in the young QCI. From a horizontal perspective (cross-sectional comparison among different groups), young QCI consistently exceeded working-age QCI, which in turn was higher than postworking QCI, both globally and within each SDI category. Moreover, the gap between the poorest QCI performance and the best QCI performance among five SDI quintiles in any given year widened with age. These findings collectively support the young QCI with a better performance and a higher convergence, relative to other age groups between 1990 and 2021, suggesting that the medical investments, clinical healthcare practice and policy priority focused on the young population are yielding success. In contrast, the absence of healthcare access and quality for working age group may reduce labour force and decrease productivity, undermining potential demographic dividends in countries undergoing demographic transition,³⁶ with adverse effects on household income, socioeconomic development and national tax revenue, etc. Lack of access to quality healthcare for postworking age group may not only cause additional mortality among the elderly but also further increase caregiving responsibilities borne by women, as women are usually thought to predominantly provide informal care for elderly family members with chronic disorders,³⁷ exacerbating gender inequity in care-taking duties. Therefore, health systems should adopt a life-course approach to health provision, emphasising continuous monitoring of disease progression and holistic health management rather than focusing solely on isolated life stages.

Clinical and public implications

For men with autoimmune diseases and their families, the favourable decline in mortality and DALYs related to this condition is encouraging. For public policymakers, health resource should be reallocated according to the evolving disease distribution, with a special focus on the older and younger men. Flexible health policies and targeted preventive strategies should be implemented in different countries and territories to reduce varying mortality. For health system managers, preparedness for healthcare system adjustment is needed to cope with the transition of disease pattern, especially in countries with a low and low–middle SDI experiencing rapid social and economic development. For clinical practice, improving access to and quality of healthcare for the working and postworking populations, while simultaneously maintaining healthcare access and quality to continue realise benefits among the young individuals is important to reduce health inequities, thereby effectively preserving reserve force for social sustainable development, promoting healthy workforce and ensuring fiscal stability as the global population ages. Professional training is required for both doctors to achieve accurate and timely diagnosis of autoimmune diseases in older and young men and caregivers to achieve healthcare across the life course. For future research, interventions that proved to be effective among women with autoimmune diseases should be examined for men too, with evidence-based prevention, management and treatment programmes. More studies focusing on promoting active ageing and decreasing child development loss in men with autoimmune diseases as well as providing cost-effective healthcare access and quality across the life course are needed.

Limitations

Several limitations should be noted. First, considering the uncertainty in GBD estimates arising from Bayesian hierarchical modelling rather than classical sampling errors, the calculation of CIs in this study may not reflect true uncertainty and cause a potential underestimation. Further high-quality real-world studies are needed to verify these results. Second, potential misdiagnosis and missed diagnosis and poor data registry system due to underdeveloped medical capacity may result in an underestimation of burden in countries with low socioeconomic development and in areas experiencing conflict. Third, our results may be affected by the methodological defects of GBD 2021. The raw data from different locations entered GBD had huge heterogeneities, which derived from the differences in autoimmune disease diagnosis, quality of death registration systems, epidemiological surveys, etc among distinct countries. To overcome these heterogeneities, GBD applied data cleaning, correction and massive advanced statistical modelling methods. However, this may cause that the findings rely heavily on the modelled data, especially in countries lacking actual data.¹³ Also, considering that the current estimates were calculated using the past-trends and covariates, the hysteresis property of GBD data should be noted. Fourth, the definition of autoimmune diseases in GBD may differ in scope from other clinical definitions, indicating that sufficient caution should be implemented when comparing our results with clinical data.

Conclusions

In summary, although the global burden of autoimmune diseases in men declined globally over the last few decades, progress in controlling these conditions has been highly uneven across regions. High mortality rates in low and low–middle SDI countries remain a major challenge to achieving universal health coverage. Significant inequities in healthcare access and quality for men with autoimmune diseases persisted across sociodemographic development levels, with lower SDI locations accessing poorer healthcare. Less convergence between best health systems and other health systems and lower performance for working and postworking populations is an issue of concern as the demographic transition is looming. To achieve the universal health coverage of Targets of Sustainable Development Goal 3, healthcare systems need to improve access to and quality of healthcare for working and postworking populations while simultaneously maintaining performance among young individuals to preserve reserve force for social development, promote healthy workforce and ensure fiscal stability in the context of global population ageing.

Data availability statement

Data are available in a public, open access repository.