Comorbidities in adults with asthma: population-based cross-sectional analysis

Problem

In people with asthma, comorbidity can significantly increase asthma morbidity and lower adherence to asthma guidelines. The objective of this study was to measure the prevalence of physical and mental health comorbidities in adults with asthma using a large nationally representative population.

Approach

Cross-sectional analysis of routine primary care electronic medical records for 1.4 million UK adults extracted from the General Practice Administration System for Scotland, examining the prevalence of 39 comorbidities in people with and without asthma, before and after adjustment for age, sex, social deprivation and smoking status using logistic regression. A sample of clinical trials cited in the pharmacotherapy section of the UK guidelines for the management of asthma were screened for information regarding comorbidities in the adult trial population.

Findings

Of 39 comorbidities measured, 36 (92%) were significantly more common in adults with asthma and 62.6% of adults with asthma had ≥1 other condition vs. 46.2% of those without. Comorbidities with the largest absolute difference in adults with asthma were: COPD, depression, painful conditions, and dyspepsia. Comorbidities with the largest relative difference in adults with asthma were: COPD, bronchiectasis, eczema/psoriasis , dyspepsia and chronic sinusitis. Depression and anxiety were more common in adults with asthma with prevalence linked to deprivation. A total of 18 clinical trials were screened of which only 8 (44%) mentioned comorbidity, all of which were to exclude patients.

Consequences

Physical and mental health comorbidity appears to be the norm in adults with asthma. However, generalisability of evidence to people with asthma and comorbidity remains uncertain.