The electronic patient record system in each participating general practice was searched for patients coded as COPD (ICPC, Second Edition code R95) and treated with ICS (ACT code R03AK and R03BA, that is, ICS in combination with a long-acting β2-agonist) or ICS as monotherapy.
These mutations were not detected among 100 healthy control subjects, suggesting a possible pathogenetic role of ACT gene defects in a subset of patients with COPD.