Prevalence of and factors associated with adult-onset asthma in different ethnic groups: The HELIUS study.

Little is known about adult-onset asthma in different ethnic groups. The aim of this study was to examine ethnic differences in the prevalence of adult-onset asthma and factors associated with this phenotype. Cross-sectional data of 23,356 participants of the HELIUS study were used, including Dutch, South-Asian Surinamese, African Surinamese, Moroccan, Turkish and Ghanaian origin participants. Adult-onset asthma was defined as: self-reported asthma symptoms or start of asthma-medication at age ≥18 years combined with a smoking history <10 pack years. The prevalence of adult-onset asthma and its association with potential risk factors were assessed by logistic regression analyses. The adjusted prevalence of adult-onset asthma was higher in the Turkish, Moroccan and South-Asian Surinamese groups (4.9-6.0%) compared to the Dutch, Ghanaian and African Surinamese origin groups (2.4-2.6%). In addition to ethnicity, age, female sex, BMI, and doctors' diagnosis of nasal allergy/hay fever and chronic sinusitis/polyps were independently associated with adult-onset asthma. There are significant differences in the adjusted prevalence of adult-onset asthma among six ethnic groups.