Corresponding author:
Inge Raadal Skov
Department of Respiratory Medicine
Odense University Hospital
J. B. Winsløws Vej 4
5000 Odense C, Denmark
E-mail: inge.raadal.skov@rsyd.dk
Fax: +45 66 12 43 05
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Abstract
Background : Oral corticosteroid use in asthma management can lead to serious adverse effects, but knowledge on usage trends are limited. We aimed to investigate this in a nationwide asthma cohort in Denmark from 1999-2018.
Methods : By use of Danish nationwide registers, we identified all young adults (18-45 years) with two or more asthma drug collections within 12 months since the age of 15 as indicative of active asthma. Oral corticosteroid use was stratified by exposure level as high use (≥5 mg prednisolone/day) and low use (<5 mg/day) per year, age groups and gender. Lorenz curves were used to express the skewness of consumption among users.
Results : We identified 318,950 unique individuals with active asthma during the study period with a median age of 29 years (interquartile range [IQR] 20-38 years) whereof 57% were women. The 1-year prevalence of oral corticosteroid users was stable at 4.8% (median, IQR 4.7%-4.8%), but with a nearly 40% decrease in high-users from 0.54% in 1999 to 0.33% in 2018. The median annual dose decreased from 500 mg/y in 1999 to 250 mg/y in 2018. We found a substantial skewness in the distribution of oral corticosteroid usage with 10% of users accounting for almost 50% of all oral corticosteroid use.
Conclusions : Although the prevalence of oral corticosteroid users among young adults with active asthma in Denmark has been relatively stable from 1999-2018, we observed a decreasing trend in the prevalence of high-users and annual consumption.
Word count : Abstract 239 words
Introduction
Asthma is the most common respiratory disease among children and adults, estimated to affect over 339 million people globally (1). It is characterized by considerable heterogeneity in both severity degrees and inflammation types (2, 3). Corticosteroids have constituted the cornerstone in asthma treatment since the 1950s due to the potent and wide-ranging anti-inflammatory effects (4). Though oral corticosteroids (OCS) were largely replaced by inhaled corticosteroids (ICS) during the 1970-80s, OCS still remain crucial in asthma management guidelines today as short-term treatment for asthma exacerbations or as last choice opportunity in long-term treatment for severe asthma (5, 6). Unfortunately, OCS use is associated with numerus adverse effects involving cardiovascular, musculoskeletal, and endocrine systems (7). While the adverse effects of long-term OCS are well recognized in asthma treatment guidelines (5), a growing amount of evidence indicate that also repeated short-term OCS use can lead to serious adverse effects due to the cumulative exposure (8-10). This risk increases at cumulative doses as low as 1 g of prednisolone corresponding to 4 lifetime courses (9, 11), which calls for an overall increased attention on appropriate OCS use in asthma treatment (12-14). Although the management of severe asthma has advanced with the access to biologic therapies, these treatments are costly and reserved to selected patients, i.e. patients with severe asthma and a high degree of type 2 inflammation (15). Consequently, frequent or long-term OCS use remain prevalent in many cases of severe or uncontrolled asthma (10).
The monitoring of OCS usage trends is crucial in order to better address and prevent OCS-related adverse effects, as well as to evaluate potential treatment changes at the arrival of biologic treatments. We therefore aimed to explore nationwide and longitudinal utilization trends of OCS among young adults with asthma in Denmark during a 20-year period, which has not previously been done.