Background/aims: Sleep-wake abnormalities are common in patients with cirrhosis but their evaluation is time consuming and laborious. The aim of this study was to assess the validity of a simple Sleep Timing and Sleep Quality Screening questionnaire (STSQS) against an established sleep quality questionnaire and daily sleep diaries.
Methods: The study population comprised 87 patients with cirrhosis and 19 healthy volunteers. All participants completed the STSQS (sleep quality score range 1-9) and the Pittsburgh Sleep Quality Index (PSQI; total score range: 0-21; scores >5 identify 'poor' sleepers); a subgroup of 35 patients and 12 healthy volunteers also kept daily sleep diaries for 2 weeks.
Results: Patients slept significantly less well than the healthy volunteers (total PSQI score: 8.4+/-4.9 vs. 4.6+/-2.5, p<0.01; STSQS sleep quality score: 4.8+/-2.1 vs. 3.6+/-1.4, p=0.02). Significant correlations were observed between the STSQS sleep quality score and the PSQI total score (healthy volunteers: R=0.75, p<0.01; patients: R=0.74, p<0.01). STSQS sleep quality thresholds were identified, which separated individuals classified as 'poor'/'good' sleepers on the basis of the PSQI (healthy volunteers: STSQS sleep quality >4: sensitivity 75%, specificity 93%; patients: STSQS sleep quality >3: sensitivity 83%, specificity 70%). The STSQS provided estimates of habitual sleep timing variables which did not significantly differ from the average data recorded in the sleep diaries, although more variability was observed in the patients.
Conclusions: The STSQS provides acceptable estimates of sleep quality and sleep timing and could be used to identify patients with cirrhosis whose sleep behaviour might require further assessment.