Validation study of the Italian version of the Sleep Hygiene Index.

Sleep hygiene rules are a set of behavioural and environmental recommendations that promote healthy and good quality sleep, playing a role in insomnia disorder. The Sleep Hygiene Index (SHI) is a self-report questionnaire developed to evaluate the practice of sleep hygiene behaviours with adequate psychometric properties in different samples. The present study aimed to translate the original version of the SHI into the Italian language and evaluate the psychometric properties of this instrument in the Italian adult population. After the translation of the SHI from the original English version into the Italian version, factorial structure, internal consistency, as well as convergent and discriminant validity were estimated. The principal component analysis showed a four-factor solution for the SHI, accounting for 52.03% of the total sample variance (F1 = 25.65%, F2 = 10.00%, F3 = 8.48% and F4 = 7.90%). Factor 1 comprised items regarding arousal; Factor 2 comprised items regarding regular sleep habits; Factor 3 comprised items about sleep environment; and Factor 4 comprised items on sleep-disrupted behaviours. The Italian version of the SHI can be regarded as a reliable tool with adequate concurrent and predictive validity for assessing sleep hygiene in Italian adults with or without insomnia symptoms.