Determination of the minimal clinically significant difference on a patient visual analog sleep quality scale.
The amount of change in quality of sleep (QOS), as measured by a 100-mm visual analog scale (VAS), that constitutes a minimum clinically significant difference was determined. A total of 428 patients with insomnia aged 55 years and older received placebo (2 weeks), prolonged release melatonin 2 mg (3 weeks) and then placebo (2 weeks). Sleep quality was assessed by the end of each period using the Leeds Sleep Evaluation Questionnaire (LSEQ) QOS variable and a five-point severity-rating scale. The mean difference between current and preceding VAS scores in patients improving or worsening by 1 point was 13 mm (95% CI 11-16). Correlation analysis indicated that a change of 1 point was associated with a mean change of 10.3 mm on the VAS. In conclusion, a change of 10 mm change in the 100-mm VAS QOS variable of the LSEQ, signifies an important change in patients' sleep quality.
Zisapel
Nava
N
Department of Neurobiochemistry, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel. navazis@post.tau.ac.il
Nir
Tali
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000627:therapeutic use; D008875:Middle Aged; D012720:Severity of Illness Index; D016037:Single-Blind Method; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis* / Q000188:drug therapy; D011795:Surveys and Questionnaires
D000975:Antioxidants; D008550:Melatonin