Faculty Proceedings, Presentations, Speeches and Lectures

Adherence Trajectories during the First Six Weeks of Pap Therapy during the First 6 Weeks of Pap Use During the First 6 Weeks of Pap Use

Event Name/Location

31st Annual Meeting of the Associated Professional Sleep Societies LLC (APSS)

Event Location / Date(s)

Boston, Massachusetts

Presentation Date


Document Type



Introduction: Prior research has shown daytime sleepiness, insomnia symptoms, and outcome expectations predict level of adherence. Limited research has examined what predicts the trajectory of cPAP adherence over time. Our aim was to examine adherence over a 6-week follow up period and what predicts it.

Methods: In this sample of 205 veterans, growth mixture modeling was used to derive trajectory of cPAP adherence based on percentage of nights where usage was greater than or equal to 4 hours. Baseline predictors included: AHI, PAP pressure, mood disorder diagnosis, daytime sleepiness, nighttime insomnia symptoms, risk perception, outcome expectation, and self-efficacy.

Results: Two trajectories emerged categorizing the sample into Adherers (27%) and Non-Adherers (73%). At week one, adherers used the machine >= 4 hours an average of 81% of nights and had a non-significant slope, indicating the week one usage was sustained over the 6-week period. In contrast, non-adherers used the machine >= 4 hours an average of 29% of nights and had a significant decline of 3.4% per week. This indicates usage >= 4 hours at week 6 would be approximately 8%. Participants increased their odds of being a Non-Adherer if they had 1) higher PAP pressure, 2) mood disorder diagnosis, 3) more daytime sleepiness, 4) more insomnia symptoms, and 5) lower self-efficacy. AHI did not predict adherence.

Conclusion: These findings suggest psychological and behavioral factors distinguish adherence trajectories over time. Future interventions should focus on these modifiable risk factors to improve cPAP adherence.