Evaluation of: Vestbo J, Anderson JA, Calverley PMA et al. Adherence to inhaled therapy, mortality and hospital admission in COPD. Thorax 64, 939-943 (2009). In chronic diseases, adherence to inhaled therapy can impact treatment effectiveness and can influence disease mortality and morbidity. In chronic respiratory diseases in general, and chronic obstructive pulmonary disease (COPD) in particular, adherence to inhaled therapy can potentially influence disease prognosis, as demonstrated in the analyses discussed in this article and a 3-year study assessing the effects of inhaled salmeterol, inhaled fluticasone and an inhaled combination over placebo in patients with moderate-to-severe COPD patients. It is demonstrated that good adherence to inhaled therapy can reduce all-cause mortality and hospital admissions. Such results are very useful in clinical practice to motivate patients to adhere to their inhaled treatment.