Sleep Hygiene Index: Dimensionality, internal consistency, and nomological validity among Colombian medical students

Background and purpose: A new version of the Sleep Hygiene Index (SHI-10) has recently been introduced, and the psychometric performance in other populations is unknown. This study aimed to determine the dimensionality, internal consistency, and nomological validity of the SHI-10 among medical students at a Colombian university. Methods: A psychometric study was designed to determine indicators of validity (construct and nomological) and reliability (internal consistency) in which 309 medical students between 18 and 39 years (M=20.83, SD=2.68) and 54.69% were female. Construct validity (dimensionality) was tested through confirmatory factor analysis, internal consistency with Cronbach's alpha and McDonald's omega coefficients, and nomological validity through correlations with the Athens Insomnia Scale, Epworth Somnolence Scale, Generalized Anxiety Disorder (GAD)-7) and Patient Health Questionnaire (PHQ-9). Results: The four-dimensional structure of the SHI-10 showed adequate indicators of goodness of fit (Satorra-Bentler's chi-square of 43.30 [df of 29, p=.04], chi-square/df of 1.49, RMSEA of .04 [90%CI .01-.06], CFI of .97, TLI of .96 and SRMR .04). The four dimensions of the SHI-10 showed values less than .70 and limited nomological validity (most Pearson correlations were less than .30). Conclusions: The SHI-10 shows a four-dimensional structure of SHI-10; however, the four dimensions of the SHI-10 present low internal consistency and limited nomological validity. More studies are needed to show the psychometric performance of the SHI-10.