Psychometric evaluation of the medical outcomes study-sleep scale in persons with overactive bladder

Background:The Medical Outcomes Study-Sleep Scale (MOS-SS) is a commonly used self-reported instrument for assessing key constructs of sleep quality and quantity. Even though the MOS-SS has successfully undergone previous validation studies in the general population, it has not been evaluated in patients with overactive bladder (OAB).Objective:The aim of this study is to evaluate the applicability of the MOS-SS to persons with a diagnosis of OAB.Methods:This study was a follow-up to a national nested case-control survey designed to provide estimates of the prevalence of OAB in the United States. OAB patients (N = 363) who consented to participate were mailed a postal survey to assess OAB symptoms and health-related quality of life. Analyses were then undertaken to assess the psychometric properties of the MOS-SS in this OAB sample. Psychometric evaluation of the MOS-SS included construct validity, internal consistency reliability, correlation between domains, floor/ceiling effects, and an examination of the factor structure. Results were compared with the original validation population of the MOS-SS by Hays and Stewart (1992).Results:Internal consistency, correlations between domains, and floor/ceiling effects were generally consistent with results from the original validation study. Factor loadings of the MOS-SS items, as well as tests of construct validity, were similar between persons with OAB and individuals in the original validation population.Conclusion:Psychometric evaluation conducted in this study supports the use of the MOS-SS instrument to assess sleep problems among persons with OAB.