Lung function change (change in pre-bronchodilator forced expiratory volume in 1 s (ΔFEV1) from maximum lung function (max0–2.5) during the first 2.5 years after diagnosis (after start of therapy) to 12-year follow-up visit) in patients with controlled and not-controlled asthma and different level of adherence (n=181)

Good adherence ≥80%Poor adherence <80%p-value
Not-controlled asthma n125
 ΔFEV1 mL·year–1−40 (−56–−20)−47 (−83–−32)0.024
 ΔFEV1 % pred·year–1−0.47 (−0.98–0.25)−0.76 (−1.40–−0.17)0.029
Controlled asthma n56
 ΔFEV1 mL·year–1−39 (−59–−24)−35 (−67–−25)0.859
 ΔFEV1 % pred·year–1−0.31 (−0.76–0.54)−0.34 (−1.10–0.07)0.271

Statistical significances were evaluated by independent-samples Mann–Whitney U-test. When patients with COPD were excluded from the analysis, ΔFEV1 was −36 (−54–−18) mL·year–1 in patients with >80% adherence and −43 (−78–−28) mL·year–1 in patients with <80% adherence and not-controlled asthma (p=0.058).