2.2. Study protocol
This study was a non-randomized controlled trial. Subjects
were grouped in chronological order with the intervention
cohort selected on days 1e15 of a given month and the control cohort selected on days 16e31 of that same month. If the intervention and control subjects were assigned to the same hospital room, one subject had to be excluded according to grouped protocol. All subjects received the St George’s Respiratory Questionnaire (SGRQ) questionnaire and a health diary in separate envelopes. Subjects completed the questionnaire and diary individually at three month and six months and returned both items by mail after being reminded by a study investigator.