Six early CPAP-usage behavioural patterns determine peak CPAP adherence and permit tailored intervention, in patients with obstructive sleep apnoea.

Background: High rates of non-adherence to continuous positive airway pressure (CPAP) in obstructive sleep apnoea hamper good clinical outcomes. Current recommendations assumes two behaviours (adherence and non-adherence) and days 7-90 follow-up post-CPAP initiation mitigates against non-adherence.

Objectives: To investigate associations between early CPAP-usage behaviours and (1) CPAP adherence at month 3 of treatment and (2) sleep centres' treatment pathways (the procedures patients undergo that may affect barriers or facilitators of CPAP adherence).

Methods: We conducted growth mixture modelling (GMM) on retrospective data from 1000 patients at 5 UK sleep centres. Night 1 to month 3 telemonitored CPAP-usage data were downloaded from 200 patients per centre who started CPAP in 2019 (100) or 2020 (100). Adherence was defined using accepted criteria (mean CPAP-usage ≥4 hours/night for ≥70% of nights).

Results: GMM identified six distinct CPAP-usage behaviour patterns over month 1. In four (54% of patients), CPAP-usage increased or decreased, in two (remaining 46%), CPAP-usage/non-usage was consistent. 62% of the cohort were non-adherent by month 3, despite pathways following current recommendations. 98% of patients who were non-adherent by month 3 were already non-adherent by month 1. Regression analysis with a separate dataset demonstrated that early CPAP-usage behaviour explained 86% of the variance in CPAP non-adherence at month 3.

Conclusions: These data, supported by previous work, indicate that recommended day 30-90 follow-up is too late to prevent CPAP non-adherence. Determining CPAP-usage behavioural pattern in week 2 identifies risk of CPAP non-adherence at month 3 and permits the possibility of tailored interventions.