Study objective: Sleep related cognitions (e.g., faulty beliefs and appraisals, unrealistic expectations, perceptual and attention bias) play an important role in perpetuating insomnia. This paper presents new psychometric data on an abbreviated version of the Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16), a 16-item self-report measure designed to evaluate a subset of those sleep related cognitions.
Design: Psychometric study of a patient-reported measure of sleep related beliefs based on existing clinical and research databases.
Participants: A total of 283 individuals (60% women; mean age of 46.6 years old) with insomnia, including 124 clinical patients and 159 research participants.
Measurements and results: Participants completed the DBAS, Insomnia Severity Index, Beck Depression and Anxiety Inventories, daily sleep diaries for 2 weeks, and 3 nights of polysomnography (research sample only) as part of a baseline assessment. The DBAS-16 was found to be reliable, as evidenced by adequate internal consistency (Cronbach alpha = 0.77 for clinical and 0.79 for research samples) and temporal stability (r = 0.83). The factor structure was similar to the original 30-item version, with 4 factors emerging and reflecting: (a) perceived consequences of insomnia, (b) worry/helplessness about insomnia, (c) sleep expectations, and (d) medication. DBAS total scores were significantly correlated with other self-report measures of insomnia severity, anxiety, and depression, but not with specific sleep parameters.
Conclusion: The psychometric qualities of this abbreviated DBAS-16 version seem adequate. This patient-reported measure should prove a useful instrument to evaluate the role of sleep related beliefs and attitudes in insomnia and to monitor change on this cognitive variable as a potential moderator of treatment outcome.