In medical studies, the efficacy of medical treatments (called interventions) is evaluated within a group of study participants. You will be given a sentence of a study report in which your task is to list the phrases that describe the intervention(s) of the study. You should list the phrase in the same order that they appear in the text, separated by commas. If no information about the interventions is mentioned, just answer with "not found". Interventions are: a specific drug, surgery, talking therapy, a lifestyle modification, control or placebo treatment. Do not include details, dosages, frequency and duration, intervention mentions that are not in an informative span of text.
--------
Question: Assessment of acute bronchodilator effects from specific airway resistance changes in stable COPD patients .

Answer: bronchodilator


Question: One third were nonsmokers .

Answer: not found


Question: Costs/QALY gained discounted at 3 % were $ 205,186 using the QWB and $ 32,643 using the CHRD .

Answer:
not found