0582 Exploring a Supplemental Measure of CPAP Adherence

Abstract Introduction Obstructive sleep apnea (OSA) is highly prevalent in the Veteran population. The prevailing treatment for OSA is positive airway pressure (CPAP), but benefits depend on regular use. CPAP adherence is operationally defined as the number of hours of CPAP use per 24-hour period at the prescribed pressure. There are a variety of alternate metrics help to describe CPAP use, with most focused on duration and some type of categorization. Given the limited utility of these kinds of CPAP metrics, we wondered if a different type of CPAP adherence metric might be warranted. Putting on the CPAP mask is a behavioral action, so we explored the value of a metric focused on putting the mask on at least once per day. Methods Participants in an CPAP trial were provided standard education about their diagnosis and treatment at baseline. Follow-up visits were held two and four months from start of treatment. Treatment adherence metrics were derived from CPAP usage data. The “anyuse” metric was defined as the percentage of nights the mask was put on at least once in a 24-hour period. Results Twenty participants had a mean age of 50.2±13.9, mean AHI of 23.3±16.0, and mean BMI of 31.3.8±4.9 (kg/m2). Nightly CPAP adherence measured over the two-month period was 2.6±1.6 hours per night (mean±SD). The average anyuse at two-month was 78% ± 0.24 (12%-100%). Anyuse was moderately correlated with CPAP adherence (r=0.682, r-squared=0.465, p< 0.001), which means that while 46% of the variance in adherence was accounted for by anyuse, 54% of the variance was not. Conclusion The anyuse metric is a relatively simple metric that might have value as a supplemental metric to CPAP adherence. Importantly, it does not overlap substantially with CPAP adherence and provides a measure of initial behavioral action. A possible related metric is a count of the number of mask on events per day. Further exploration of these metrics appears to be warranted. Support (if any) This project was supported in part by the VA HSR&D IIR 16-277 and the VA San Diego Healthcare System Pulmonary Sleep Medicine Section and Research Service.