Beyond Asthma: Study Examines the Strength of Comorbidity Associations

Investigators underline the importance of using a multidimensional approach when treating patients with asthma, specifically when assessing whether poor symptom control is related to uncontrolled asthma or underlying comorbidities.¹

The need for individualized strategies of disease management to look beyond asthma is supported by results from a meta-analysis. Study findings suggest that comorbidities are highly prevalent in individuals with asthma and can significantly impact asthma severity, treatment response, and overall health outcomes.

Paola Rogliani, MD, Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome Tor Vergata, and the team of investigators aimed to evaluate the strength of association between asthma and comorbidities. They stated that this relationship has not been systematically ranked in relation to the prevalence of comorbidity in the non-asthma population.

Uncontrolled Asthma or Underlying Comorbidity?

Strong associations were displayed between asthma and allergic rhinitis, allergic conjunctivitis, bronchiectasis, hypertensive cardiomyopathy, and nasal congestion. Stronger associations were detected comorbidities and severe asthma.

An especially strong association was shown between chronic obstructive pulmonary disease (COPD) and asthma. However, the complexity of associations such as this was acknowledged in the research.

“The very strong level of association between COPD and asthma or severe asthma could be related to potential misclassification between the diseases due to the overlap of symptoms and clinical features, particularly in elderly patients and smokers who experience poor symptom control, frequent exacerbations, progressive lung function deterioration and impaired quality of life,” investigators wrote.

When analyzing psychiatric comorbidities, investigators observed some conditions like panic attack, phobia, psychiatric disorder, and suicidal ideation reached strong association levels.

Affective disorder, Alzheimer’s disease, anxiety, depression, migraine, panic attack, phobia, psychiatric disorder, somatoform disorder, and suicidal ideation exhibited moderate associations.

Large-scale Analysis of Asthma

After more than 2000 records were screened for relevance, 33 studies were deemed eligible for qualitative and quantitative syntheses, including 15 cross-sectional studies, 14 cohort studies, and four case-control studies.

The final analysis included data from more than 5 million individuals. The dataset consisted of 878,224 patients with asthma, 1791 of whom were affected by severe asthma. Non-asthmatic individuals made up the remainder of the study population.

Observational studies with reported data on comorbidities in asthma and nonasthma populations were targeted using MEDLINE, Embase, and Web of Science databases, from inception to October 2021.

Studies were included if they reported the odds ratios (ORs) and 95% confidence intervals (CIs) of comorbidities in asthma and nonasthma populations. The team performed a pairwise meta-analysis, and the strength of association was calculated using Cohen's d method, which anchored ORs and 95% CIs with the rate of comorbidities in nonasthma populations.

It was noted that quality assessment showed two cohort studies and two case-control studies were considered high quality, while 12 cohort studies and two case-control studies were regarded as of low quality. The inter-rater and intra-rater reliability for data abstraction were both excellent.

The study stressed the need for further research to facillitate better understanding of the complex relationships between asthma and comorbidities, along with the development of effective treatment strategies for individuals with asthma.

References:

1. Rogliani P, Laitano R, Ora J, Beasley R, Calzetta L. Strength of association between comorbidities and asthma: a meta-analysis. Eur Respir Rev. 2023;32(167):220202.