Ethnicity‐based differences in the incident risk of allergic diseases and autoimmune disorders: A UK‐based retrospective cohort study of 4.4 million participants

The burden of allergic diseases (ADs) such as asthma and rhinitis and autoimmune disorders (AIDs) such as rheumatoid arthritis (RA) are relatively low/moderate in low and low-middle income countries1,2 and there is some evidence regarding higher incidence rates of these conditions amongst immigrant population settled in high income countries3,4 . The burden of ADs are particularly high in high income countries such as UK, Republic of Ireland and New Zealand1 . Studies in immigrants have been limited by several factors including relatively small sample size, shorter duration, and methodological issues such as selection bias, survey or questionnaire-based data, focus on a single or limited number of ADs or AIDs, and some not accounting for important disease confounders such as smoking history.