Background/Purpose: Almost every organ system can be affected by primary immune-mediated diseases characterized by inflammation and therapeutic response to immune-suppressive or anti-inflammatory drugs. These diseases can be collectively referred to as immune-mediated inflammatory diseases (IMID). Many rheumatic diseases can be categorized as IMIDs. Since IMIDs are purported to have shared pathogenic mechanisms, it would be important to understand their burden of disease together. Our goals are to determine 1) the burden of IMID deaths relative to the leading causes of death published by the Centers for Disease Control and Prevention (CDC) and 2) the mortality trends of top 15 individual IMIDs.

Methods: We compiled 43 IMIDs with a reported prevalence of >1 per 100,000 population, and obtained death counts for each of them using the CDC-WONDER database. We then calculated their crude death rates, pooled death counts of the 15 IMIDs with the highest crude death rates, and ranked the pooled IMID death counts among the CDC’s official leading-causes-of-death ranklist for eleven age groups. Next, we calculated the annual age-standardized mortality rate (ASMR) for the top 15 individual IMIDs from 1999 to 2017. Lastly, we performed joinpoint trend analysis of the annual ASMRs for these 15 IMIDs.

Results: 371,154 deaths were attributed to the top 15 IMIDs in 5 years from 2013 to 2017. Of these deaths, IMIDs were recorded as the underlying cause in 202,430 deaths and as the contributing cause in 168,724 deaths. These IMID deaths (underlying + contributing) ranked 6th to 9th for all age groups among the leading causes of death. When only the underlying cause of death was considered, IMID ranked among the top 15 for all age groups and 7th to 9th in 15 to 64 year age groups. Among IMIDs, primary interstitial lung disease, multiple sclerosis, and type 1 diabetes had the highest ASMRs in 2017 followed by rheumatic diseases including rheumatoid arthritis, lupus, systemic sclerosis, and systemic vasculitis, which ranked in the top 10. Joinpoint trend analysis showed that annual mortality rates for most IMIDs including rheumatoid arthritis, lupus, systemic sclerosis, systemic vasculitis, type 1 diabetes, myocarditis, primary biliary cirrhosis, and idiopathic thrombocytopenic purpura have decreased from 1999 to 2017, but have increased or unchanged for a few IMIDs including primary interstitial lung disease, multiple sclerosis, and myasthenia gravis.

Conclusion: Ranking of IMID among the top ten leading causes of death emphasizes the high burden of diseases characterized by inflammation. These data further highlight that IMID is a major public health problem. Similar to various forms of cancer, various IMIDs should be considered as a collective disease entity. The recognition of IMID as a leading cause of death may influence healthcare prioritization and research funding, which may help to reduce their disease burden.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/immune-mediated-inflammatory-diseases-imid-collectively-rank-among-the-leading-causes-of-death/