A randomized controlled trial of CBT-I and PAP for obstructive sleep apnea and comorbid insomnia: main outcomes from the MATRICS study

Abstract

Study objectives: To investigate treatment models using cognitive behavioral therapy for insomnia (CBT-I) and positive airway pressure (PAP) for people with obstructive sleep apnea (OSA) and comorbid insomnia.

Methods: 121 adults with OSA and comorbid insomnia were randomized to receive CBT-I followed by PAP, CBT-I concurrent with PAP, or PAP only. PAP was delivered following standard clinical procedures for in-lab titration and home setup and CBT-I was delivered in four individual sessions. The primary outcome measure was PAP adherence across the first 90 days, with regular PAP use (≥4 h on ≥70% of nights during a 30-day period) serving as the clinical endpoint. The secondary outcome measures were the Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) with good sleeper (PSQI <5), remission (ISI <8), and response (ISI reduction from baseline >7) serving as the clinical endpoints.

Results: No significant differences were found between the concomitant treatment arms and PAP only on PAP adherence measures, including the percentage of participants who met the clinical endpoint. Compared to PAP alone, the concomitant treatment arms reported a significantly greater reduction from baseline on the ISI (p = .0009) and had a greater percentage of participants who were good sleepers (p = .044) and remitters (p = .008). No significant differences were found between the sequential and concurrent treatment models on any outcome measure.

Conclusions: The findings from this study indicate that combining CBT-I with PAP is superior to PAP alone on insomnia outcomes but does not significantly improve adherence to PAP.

Keywords: cognitive behavioral therapy for insomnia; comorbid insomnia; obstructive sleep apnea; positive airway pressure.

Figure 1.

The CONSORT flow diagram depicting participant flow. In Arm A, Phase I consisted of 4 weeks (28 days) of CBT-I and in Arms B and C, Phase I consisted of 4 weeks (28 days) of sleep diary monitoring. For all Arms, Phase II consisted of PAP therapy for 90 days.

Figure 2.

Regular use of PAP by treatment arm. The percentage of participants per arm who were categorized as regular or not regular users based on the clinical endpoint criteria for regular use of PAP defined as use at least 4 h on at least 70% of nights during a 30-day window within the 90-day study period. Participants who had missing data were categorized as not regular users.

Figure 3.

The PSQI at baseline (A1) and 90 days (A4, study endpoint that occurred 90 days after PAP initiation). The data table shows mean and standard deviations in parentheses for each arm. A significant main effect over time was found indicating that sleep quality improved from baseline to study endpoint across all treatment arms, F(1, 101) = 153.35, p < .0001.

Figure 4.

The ISI total score at each assessment point from baseline (A1), PAP start (A2), 30 days (A3, assessment at 30 days after PAP start), and 90 days (A4, study endpoint that occurred 90 days after PAP start). During Phase I, Arm A received CBT-I and Arms B and C received no active intervention. During Phase II, all treatment arms received PAP starting at A2 (PAP start) while Arm B received CBT-I between PAP start and the 30-day assessment. The data table shows mean and standard deviations in parentheses for each arm. Significant main effects were found over time, F(3, 308) = 142.15, p < .0001, and between treatment arms, F(2, 308) = 3.17, p = .0434. There was also a significant time by treatment interaction, F(6, 308) = 3.89, p = .0009.

Figure 5.

Percentage of participants per arm who meet categorical outcomes at the study endpoint (A4). Good sleepers were defined as PSQI total score of less than 5 at the study endpoint. Insomnia remission was defined as the ISI score less than 8 at the study endpoint. Insomnia response was defined as a reduction in the ISI score more than 7 points from baseline to study endpoint. Significant differences were found with more good sleepers in Arms A and B compared to Arm C, χ ²(1) = 4.063, p = .044 and more treatment remission in Arms A and B compared to Arm C, χ ²(1) = 7.021, p = .008. The pattern was in the predicted direction for treatment response, but the difference between groups did not reach significance, p = .083. There was no difference in good sleeper status, remission, and response between Arms A and B.