Background: It remains unclear to what extent asthma in adults is linked to allergic rhinitis (AR), gastroesophageal reflux disease (GERD), and acetylsalicylic acid exacerbated respiratory disease (AERD), and how these comorbidities may affect asthma outcomes in the general population. We therefore aimed to assess the prevalence of these major comorbidities among adults with asthma and examine their impact on asthma exacerbations requiring hospital care.
Methods: A total of 22,050 adults 18 years and older were surveyed in the German National Health Telephone Interview Survey (GEDA) 2010 using a highly standardized computer-assisted interview technique. The study population comprised participants with self-reported physician-diagnosed asthma, among which the current (last 12 months) prevalence of AR and GERD-like symptoms (GERS), and life-time prevalence of AERD was estimated. Weighted bivariate analyses and logistic regression models were applied to assess the association of each comorbid condition with the asthma outcome (any self-reported asthma-related hospitalization and/or emergency department (ED) admission in the past year).
Results: Out of 1,136 adults with asthma, 49.6% had GERS and 42.3% had AR within the past 12 months; 14.0% met the criteria of AERD, and 75.7% had at least one out of the three conditions. Overall, the prevalence of at least one exacerbation requiring emergency room or hospital admission within the past year was 9.0%. Exacerbation prevalence was higher among participants with comorbidities than among those without (9.8% vs. 8.2% for GERS; 11.2% vs. 7.6% for AR, and 22.2% vs. 7.0% for AERD), but only differences in association with AERD were statistically significant. A strong association between asthma exacerbation and AERD persisted in multivariable logistic regression analyses adjusting for sex, age group, level of body mass index, smoking status, educational attainment, and duration of asthma: odds ratio (OR) = 4.5, 95% confidence interval (CI) = 2.5-8.2.
Conclusions: Data from this large nation-wide study provide evidence that GERS, AR and AERD are all common comorbidities among adults with asthma. Our data underline the public health and clinical impact of asthma with complicating AERD, contributing considerably to disease-specific hospitalization and/or ED admission in a defined asthma population, and emphasize the importance of its recognition in asthma care.