Inpatient vs outpatient cognitive behavioral therapy for insomnia: A two-arm parallel randomized controlled trial

While outpatient cognitive behavioral therapy for insomnia (CBT-I) represents the most efficacious delivery method, approximately 50 % of patients are unable to achieve clinical remission. There is a pressing need to develop more effective approaches to CBT-I delivery. This study assessed the comparative efficacy of one-week inpatient CBT-I and eight-week standard outpatient CBT-I.

A randomized controlled trial was conducted with 200 adults with chronic insomnia disorder. These participants were randomly allocated to either the inpatient group (n = 100) or the outpatient group (n = 100). The inpatient group underwent a one-week intensive inpatient CBT-I followed by weekly follow-ups program. The outpatient group participated in a standard outpatient CBT-I program conducted on an individual basis over an eight-week period. The primary outcome was the insomnia severity index score at 9 weeks after the start of intervention. Linear mixed effects model was employed for the intention-to-treat analysis.

At the 9-week assessment, the inpatient CBT-I group demonstrated a mean change in insomnia severity index score of -13.31 (95 % confidence interval [CI], -14.47 to -12.16; Cohen's d = -3.18; P < .001). The outpatient group showed a mean change of -11.14 (95 % CI, -12.30 to -9.98; Cohen's d = -2.66; P < .001). The mean difference between groups was -2.03 (95 % CI, -3.21 to -0.85; Cohen's d = -0.48; P < .001), indicating a statistically significant improvement in the inpatient group compared to the outpatient group.

This study demonstrated that inpatient CBT-I exhibited superior efficacy compared to outpatient CBT-I in alleviating insomnia severity.