Socioeconomic biases in asthma control and specialist referral of possible severe asthma

Background: Although socioeconomic impact on asthma control has been investigated, little is known about its relationship to specialist referral of patients with possible severe asthma, especially in a public healthcare setting. The present study aims to identify socioeconomic patterns in disease control and referral of patients with asthma in a nationwide cohort of adult patients treated with inhaled corticosteroids (ICS).

Methods: Asthma patients fulfilling the following criteria were included: aged 18-45 years and redeeming two or more prescriptions of ICS during 2014-2018 based on data from Danish national registers. Possible severe asthma was defined as Global Initiative for Asthma 2020 step 4 (with either two or more courses of systemic steroids or at least one hospitalisation) or step 5 treatment. Findings presented as odds ratios (95% confidence intervals).

Results: Out of 60 534 patients (median age 34 years, 55% female), 3275 (5.7%) were deemed as having possible severe asthma, of whom 61% were managed in primary care alone. Odds of specialist management for possible severe asthma decreased with age (OR 0.66, 95% CI 0.51-0.85; 36-45 versus 18-25 years), male sex (OR 0.75, 95% CI 0.64-0.87), residence outside the Capital Region (OR 0.70, 95% CI 0.59-0.82) and with receiving unemployment or disability benefits (OR 0.75, 95% CI 0.59-0.95). Completion of higher education increased odds of specialist referral (OR 1.28, 95% CI 1.03-1.59), when compared to patients with basic education.

Conclusion: Even in settings with nationally available free access to specialist care, the majority of patients with possible severe asthma are managed in primary care. Referral of at-risk asthma patients differs across socioeconomic parameters, calling for initiatives to identify and actively refer these patients.