Test-retest reliability of the questionnaire on the screening of sleep disorders

Abstract
Sleep is a vital component for maintaining good physical and mental health. When sleep is disordered, it can adversely affect an individual's mental and physical wellbeing. Although a variety of single specific disorder measurements are available for specialized clinicians use across the globe, to date, there are no proper screening instruments available for screening multiple sleep disorders at the primary care level. The purpose of this study is to determine the test-retest reliability of the sleep disorder screening questionnaire (SDSQ) for detecting multiple sleep disorders among the Mongolian population. A total of 366 university students were recruited for participation. SDSQ was administrated to all participants on two occasions two weeks apart. The test-retest reliability intra-class correlation (ICC) and Cronbach's alpha of the SDSQ were calculated. The sample consisted of 194 (53%) females, and 172 (47%) males, with a mean age of 21.6. Observed test-retest reliability was ranged from 0.53 to 0.81. The SDSQ was found to have excellent internal consistency with an alpha=0.950. The external validity of SDSQ revealed strong test-retest reliability in the current study population. The discriminant and convergent validity studies are required for the further improvement of the construct of the SDSQ.