Efficacy of the ‘Quarter-of-an-Hour-Rule’ Single Instruction Derived from Stimulus Control Therapy for Insomnia: A Pragmatic Open-Label, Randomized Controlled Trial

STUDY OBJECTIVES: This study explored the preliminary effects of the quarter-of-an-hour-rule (QHR), a single instructional element of stimulus control therapy (SCT) for insomnia. METHODS: = 30, 68% female; mean age 47.4 ± 13.3 years), recruited in primary care and meeting diagnostic criteria for chronic insomnia, were randomized to QHR implemented either out of bed [QHR(Out)], in bed [QHR(In)], or to a self-monitoring control group (SMC). Intervention was delivered by a single in-person session, with telephone support (total time c.60 minutes). Sleep pattern was assessed throughout the study by sleep diary and 2 nights of home-based polysomnography (PSG) at pre- and post-treatment. Sleep quality was appraised using the Pittsburgh Sleep Quality Index (PSQI). Treatment adherence (self-reported and actigraphy-estimated) and treatment credibility data were collected. RESULTS: Significant group-time interaction effects confirmed that QHR(Out) and QHR(In) were associated with reductions in self-reported sleep-onset latency (SOL) and wake-time after sleep-onset (WASO), and improvements in sleep efficiency (SE), relative to no change in SMC. PSG-defined sleep outcomes did not improve. However, subjective-objective sleep discrepancy (SOSD) in the index measure, SE, reduced following both interventions. The interventions were regarded as credible, and overall, SE improvement was c.14% following treatment. Subjective adherence was higher than objectively estimated, although the differential was smaller in the QHR(In) group. CONCLUSIONS: The QHR, a simple and brief derivative of SCT, appears efficacious for insomnia on pre-post analysis. Longer-term clinical effectiveness studies on the QHR(Out) and QHR(In) protocols appear warranted. Experimental investigation of how the QHR addresses the fundamentals of sleep-related stimulus control would be valuable. TRIAL REGISTRATION: NCT00170391, https://clinicaltrials.gov/study/NCT00170391.