2.2 Asthma subgroups
Based on the presence and severity of asthma during baseline and
follow-up, patients with CRSwNP were divided into subgroups: no asthma,
mild to moderate asthma, severe controlled asthma, and severe
uncontrolled asthma. Patients were considered to have asthma if they had
an ICD-10: J45 diagnosis at least twice or at least two asthma
controller medication purchases (inhaled corticosteroids (ICS) in single
inhalers (ATC-codes: R03BA01, R03BA02, R03BA05, R03BA07, R03BA08,
R03BA09) or in combination with long-acting beta-2-agonists (R03AK06,
R03AK07, R03AK08, R03AK09, R03AK10, R03AK11)). Severe asthma was defined
as asthma with a daily use of fluticasone propionate ≥ 800 µg or
equivalent (80% adherence to 1 000 µg of fluticasone propionate or
equivalent) complemented with at least one other controller (Leukotriene
Receptor Antagonists (LTRA), Long-acting beta-agonist (LABA),
Long-acting muscarinic antagonists (LAMA), or biologic asthma
medication). The daily average ICS use was calculated as fluticasone
propionate equivalent based on a sliding window of three consecutive
purchases (the total micrograms of ICS at three consecutive purchases
were divided by days from the first purchase to the fourth consecutive
purchase). The patients with severe asthma were further divided into
those with controlled and uncontrolled asthma. Asthma was considered
uncontrolled in patients who had been hospitalized for asthma (ICD:10
J45-J46), had a record of emergency room visit for asthma (ICD:10
J45-J46), or had an outpatient visit for acute asthma (ICD-10: J46).