Assessment of Outcomes
SECONDARY
Our primary CPAP adherence outcome variables were generated over 90 days for each group: mean hours used per night (continuous) and mean number of nights used per week (continuous). Our secondary CPAP adherence outcome was the percentage of participants reaching the CMS adherence threshold. Days of nonuse were imputed with an adherence of 0 hours per night. Some participants completed their final study visit in the final week before day 90 because of planning challenges. These participants were censored, and it was assumed that they continued with therapy as before in the final days until day 90 (ie, missing data did not contribute to the model estimates).Subjective secondary outcomes were assessed at different time points. The self-efficacy, perceived importance, outcome expectations, and motivation questionnaires were repeated on days 11, 56, and 90, whereas the ESS was repeated on days 56 and 90. A single item assessing satisfaction with CPAP therapy on a scale of 0 to 10 was completed on days 11, 56, and 90.