Evaluating the treatment of obstructive sleep apnea comorbid with insomnia disorder using an incomplete factorial design.

Chronic insomnia disorder is a prevalent condition and a significant proportion of these individuals also have obstructive sleep apnea (OSA). These two sleep disorders have distinct pathophysiology and are managed with different treatment approaches. High comorbidity rates have been a catalyst for emerging studies examining multidisciplinary treatment for OSA comorbid with insomnia disorder. In this article, we describe a randomized clinical trial of cognitive behavioral treatment for insomnia (CBT-I) and positive airway pressure (PAP) for OSA. Participants are randomized to receive one of three treatment combinations. Individuals randomized to treatment Arm A receive sequential treatment beginning with CBT-I followed by PAP, in treatment Arm B CBT-I and PAP are administered concurrently. These treatment arms are compared to a control condition, treatment Arm C, where individuals receive PAP alone. Adopting an incomplete factorial study design will allow us to evaluate the efficacy of multidisciplinary treatment (Arms A & B) versus standard treatment alone (Arm C). In addition, the random allocation of individuals to the two different combined treatment sequences (Arm A and Arm B) will allow us to understand the benefits of the sequential administration of CBT-I and PAP relative to concurrent treatment of PAP and CBT-I. These findings will provide evidence of the clinical benefits of treating insomnia disorder in the context of OSA.