Same scale, different names? An assessment of the psychometric properties of three established scales that measure cognitive processes in insomnia, and the introduction of the sleep worry 7 questionnaire

The overlap between the three scales was neither large enough to conclude that they are measuring the same construct, nor could it be confirmed that they measure three distinct questionnaire-specific cognitive processes within insomnia. The brief scale created within this study was able to predict persistent insomnia at similar levels to the three established scales combined, indicating that it captures important cognitions involved in the maintenance of insomnia. Measuring sleep-related cognitions with fewer items might be beneficial in both clinical contexts and research.