Use of the single‐item Patient Global Impression‐Severity scale as a self‐reported assessment of insomnia severity. (30th July 2020)

• Record Type: Journal Article
• Authors: Snyder, Ellen S.; Tao, Peining; Svetnik, Vladimir; Lines, Christopher; Herring, W. Joseph
• Is Part Of: Journal of sleep research. Volume 30:Number 1(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-30
• Subjects: orexin -- rating instruments -- sleep; Sleep -- Periodicals; Sleep disorders -- Periodicals; 612.821
• DOI: 10.1111/jsr.13141
• Languages: English
• ISSNs: 0962-1105

Abstract

Abstract: We evaluated a single‐item Patient Global Impression‐Severity (PGI‐S) scale for assessing insomnia severity during the clinical development programme for suvorexant. The analyses used data from two randomised, double‐blind, placebo‐controlled, 3‐month, Phase III clinical trials of suvorexant in patients with Diagnostic and Statistical Manual of Mental Disorders IV criteria insomnia. Patients assessed insomnia severity during the previous week using the PGI‐S, a one‐item questionnaire containing six response options ranging from 0 (none) to 5 (very severe), at baseline and at Week 2, and Months 1, 2, and 3 after randomisation. The seven‐item Insomnia Severity Index (ISI) and other subjective and objective assessments were also completed by patients. PGI‐S responses were compared primarily with the ISI using descriptive statistics and correlations. The PGI‐S demonstrated favourable measurement characteristics (validity, reliability, responsiveness and sensitivity). PGI‐S scores decreased from baseline to Month 3 in a similar pattern to the ISI total score, and the Spearman correlation coefficient between PGI‐S and the ISI was .73. An improvement of ≥2 points on the PGI‐S defined a treatment responder, based on comparison to the ISI definition of a responder (improvement of ≥6 points). Our present findings suggest that the PGI‐S is a simple but valid, reliable, responsive, sensitive, and meaningful patient‐reported assessment of insomnia severity. The PGI‐S may be particularly useful as a companion outcome to sleep monitoring using wearable sleep devices or smartphones in at‐home settings.