Introduction: Fear of sleep is one of the important constructs related to post-traumatic stress disorder (PTSD) that can play a role in the persistence of sleep disorders and psychological problems. Despite the importance of this construct, measurement tools for it have been less studied in the Iranian cultural context. This study aimed to investigate the psychometric properties of the Fear of Sleep Questionnaire in spouses of veterans with PTSD.
Methods: This descriptive-cross-sectional study was conducted on 164 spouses of veterans with PTSD. Translation of the instrument was performed using the forward-backward translation method. Face validity, content validity, construct validity, and convergent validity, as well as reliability using Cronbach's alpha, test-retest, and absolute stability indices including Standard Error of Measurement (SEM), Minimum Detectable Change (MDC), and Minimal Important Change (MIC) were examined. Exploratory factor analysis was performed using the principal components method.
Results: In face validity, all items were comprehensible. In content validity, most items had a CVR higher than 0.62 and an I-CVI higher than 0.78. The KMO index was 0.851, and Bartlett's test was significant (p<0.001). Factor analysis extracted three main factors including Nightmares, Safety during Sleep, and Fear of Sleep, which explained 56