Psychometric properties of Glasgow Sleep Effort Scale in Portuguese language

Sleep effort is generally defined as the attempt to force and induce sleep in a voluntary manner. This study aimed to document the psychometric properties of a brief measure of sleep effort--the Glasgow Sleep Effort Scale--in its European (Portuguese) version using a large sample (N = 2,995). The results supported the good internal consistency of the overall scale scores (α = .79). Potential construct validity was evaluated with various methods, including criterion validity. There was also a convergent validity indicator. Principal components analysis revealed a 1-dimensional structure that accounted for 45% of the total variance. This preliminary study suggests that this Portuguese version of the Glasgow Sleep Effort Scale is a measure of sleep behavior suitable for research and clinical purposes. However, more studies are needed, particularly with clinical groups.