Cumulative corticosteroid exposure in severe asthma prior to commencing biologics – a nationwide 27-year observational study

<bold>Introduction</bold> The cumulative systemic corticosteroid burden in asthma has been shown to be associated with morbidity and mortality. However, little is known about the long-term total steroid burden in patients with severe asthma. <bold>Methods</bold> Patients in the nationwide Danish Severe Asthma Registry were linked to the national prescription registry to retrieve all redemptions of inhaled, nasal, and systemic (oral and injectable) corticosteroids from 1995 until the first administration of a biologic for severe asthma. Cumulative prednisolone-equivalent doses (1000 µg budesonide = 2 mg prednisolone) were stratified according to mode of administration and redemption before the first registered respiratory outpatient visit (yes/no). <bold>Results</bold> In 777 patients followed for a median of 17 (IQR 9, 22) years, the median total cumulative steroid exposure prior to biologic treatment was 14.8 (7.7, 30.2) g, corresponding to approx. 40 10-day rescue courses of prednisolone. Systemic steroids accounted for 6.3 (2.8, 14.5) g or 57% of the total median steroid burden. Corresponding exposure for inhaled and nasal steroids were 6.4 (3.0, 12.7) g (40%) and 0.3 (0.04, 0.8) g (3.3%) respectively. Thirty-seven percent of cumulative steroid exposure occurred before the first visit to a respiratory outpatient clinic, and 31% of systemic steroids were redeemed before specialist assessment. <bold>Conclusion</bold> Patients with severe asthma have a substantial cumulative steroid exposure prior to biologic treatment, with a large proportion occurring prior to their first specialist assessment. Earlier referrals could help reduce steroid-related comorbidities and steroid burden.