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Determination of the minimal clinically significant difference on a patient visual analog sleep quality scale
Author(s) -
Zisapel Nava,
Nir Tali
Publication year - 2003
Publication title -
journal of sleep research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 117
eISSN - 1365-2869
pISSN - 0962-1105
DOI - 10.1046/j.0962-1105.2003.00365.x
Subject(s) - visual analogue scale , placebo , sleep quality , medicine , rating scale , insomnia , anesthesia , significant difference , melatonin , physical therapy , psychology , psychiatry , developmental psychology , alternative medicine , pathology
Summary 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.