Clinical and polysomnographic predictors of short-term continuous positive airway pressure compliance

Poor compliance and initial intolerance limit the effectiveness of continuous positive airway pressure (CPAP) in obstructive sleep apnea. Short-term compliance has been shown to predict long-term use. Unfortunately, few identified variables reliably predict initial CPAP tolerance and use. We sought to identify potential pretreatment variables that would predict short-term use of CPAP.

We performed a retrospective review assessing short-term CPAP compliance after 4 to 6 weeks of treatment. Consecutive patients initiating CPAP therapy were included. Demographic and polysomnographic variables were correlated with objective measures of CPAP use. The average hours per night and percentage of nights of CPAP use were correlated with each variable. Variables were also associated with good vs poor compliance, which we defined as > 4 h per night > 70% of nights.

We included 400 consecutive patients (78% male; mean age, 47 +/- 8 years). Of the measured variables, only age (48 +/- 8 years vs 46 +/- 7 years, p = 0.02) and use of a sedative/hypnotic during CPAP titration (77% vs 57.6%, p < 0.0005) were associated with better compliance. Those receiving a sedative/hypnotic had longer sleep times (345 +/- 42 min vs 314 +/- 51 min, p < 0.0005) and greater sleep efficiency (84 +/- 9% vs 78 +/- 11%, p < 0.0005) during polysomnography. CPAP titrations were improved in those receiving sedative/hypnotics, achieving lower respiratory disturbance index on the final CPAP pressure (6 +/- 7 vs 10 +/- 11, p = 0.04).

Of the measured variables, only age and a one-time use of sedative/hypnotics during polysomnography correlated with greater short-term CPAP compliance. Hypnotics facilitated better quality CPAP titrations. Reliable predictors of short-term CPAP use could help identify measures to improve long-term compliance.