FIGURE 1.

a) Study flow, with two-period crossover design. In sequence A–B, participants first received video instruction only (intervention A), followed by use of the Lung Flute ECO (intervention B). In sequence B–A, participants received the two interventions in the opposite order. b) Proportions of participants for primary outcome of whether participant produced >1 mL of sputum, by sequence, for each combination of outcomes on the two sputum collection attempts. ^#: reasons for exclusion: vomiting (n=36), haemoptysis (n=18), asthma with recent acute exacerbation (n=15), nausea grade 3 or 4 (n=12), dyspnoea grade 3 or 4 (n=12), other (n=27); some reasons overlap. ***: p<0.001.