Bangla version of the composite scale of morningness: factor invariance and validity with sleep habits, mood and mental health

The Composite Scale of Morningness (CSM) is a self-report measure of circadian preference that is related with one's physical and mental health. This study aimed to explore the psychometric properties of the Bangla version of the CSM and validate it with sleep habits, BRUnel Mood Scale (BRUMS) and Positive Mental Health Scale (PMH-scale). The sample consisted of 1164 (38.8% women) Bangladeshi university students aged between 18 and 27 (M = 21.9, SD = 1.88). Using confirmatory factor analysis, the competing factorial models of the CSM and measurement invariance for sex were tested. The Bangla CSM showed high internal consistency reliability (alpha = .88) and excellent retest reliability (ICC = .92). The cut-off values for the Bangla CSM were 26 or less for evening-types (lower 10 percentiles) and 46 or more for morning-types (upper 10 percentiles). The Bangla CSM consisted of two components: morningness and morning affect. From eight factorial models, the two-factor bifactor model was found invariant for sex. Higher CSM score (morningness) was significantly related with earlier sleep times, better mood and mental health, which support its validity. The CSM is a valid and psychometrically robust tool for assessing morningness-eveningness in Bangladeshi students.