Association between mental health disorders and asthma exacerbations in adults: a retrospective cohort study in UK primary care

Aim To evaluate the association between the presence or absence of comorbid mental health disorders and the risk of asthma exacerbations in adults with prevalent asthma.

Methods This was a cohort study of adults in England with prevalent asthma and mental health disorders (depression, anxiety, bipolar disorder and schizophrenia) between 2017 and 2019 using primary care electronic healthcare records.

Adult asthma patients with mental health disorders (exposed) were matched by age, sex, ethnicity and general practice to asthma patients without a mental health disorder (unexposed) in a 1:1 ratio. The primary outcome was an exacerbation of asthma documented in primary care records. Poisson regression was used to estimate adjusted incidence rate ratios (IRR).

Results 873 482 adults with asthma were followed up for a total of 1 580 157 years.

Mean age was 49 years; 66% were female, and 78% were white. Adults with asthma and any mental health disorder had an asthma exacerbation incidence rate of 56 per 1000 person years compared with 34 per 1000 person years for those without a mental health disorder.

Adults with asthma and any mental health disorder had an adjusted IRR of 1.46 (95% CI 1.44 to 1.48) compared with matched controls. The highest IRR was in those with depression (IRR 1.34, 95% CI 1.32 to 1.37), followed by those with anxiety (IRR 1.20, 95% CI 1.18 to 1.22). There were no significant differences in patients with bipolar disorder or schizophrenia compared with matched controls (IRR 1.00, 95%CI 0.93 to 1.07; and 1.03, 95% CI 0.95 to 1.11, respectively).

Conclusion This study shows a significant increased risk of asthma exacerbations in asthma patients with depression or anxiety compared with those with asthma without comorbid mental health disorders.