Effects of subjective-objective sleep discrepancy on the response to cognitive behavior therapy for insomnia

This study aimed to evaluate the clinical correlates of sleep discrepancy and how subjective-objective sleep discrepancy (SD) affects the results of cognitive behavioral therapy for insomnia (CBT-I) in patients with insomnia disorder. A total of 33 patients aged >55 years with insomnia disorders participated in this prospective cohort study. Sleep discrepancy (SD) was defined as the difference between the sleep duration derived from the PSG and self-report questionnaires. SD > 2 h was classified as high SD. Self-report questionnaires, and polysomnography (PSG) were performed before 4 weeks of group CBT-I. Statistical analyses were performed to investigate the association of SD with baseline characteristics and CBT-I results, and compare intergroup difference of pre and post-treatment of high SD and low SD. Patients in the high SD group reported poor subjective sleep, such as lower sleep quality, shorter sleep duration, longer sleep latency, and lower sleep efficiency. However, they had longer sleep duration, higher sleep efficiency in the PSG. There were 35% males in low SD group, but no males in high SD group. After 4 weeks of group CBT-I, SD was positively associated with the effect of CBT-I on subjective total sleep time (r = 0.499, p