Application of Inverse-Probability-of-Treatment Weighting to Estimate the Effect of Daytime Sleepiness in Obstructive sleep apnea patients

Continuous positive airway pressure (CPAP), the first line therapy for obstructive sleep apnea (OSA), is considered effective in reducing daytime sleepiness. Its efficacy relies on adequate adherence, often defined as >4 hours per night. However, this binary threshold may limit our understanding of the causal effect of CPAP adherence and daytime sleepiness and multilevel approach for CPAP adherence can be more appropriate.