Development of the Pain-Related Beliefs and Attitudes about Sleep (PBAS) Scale for the Assessment and Treatment of Insomnia Comorbid with Chronic Pain.

STUDY OBJECTIVES: Dysfunctional beliefs and attitudes about sleep is a cognitive-behavioral factor central to the development and perpetuation of insomnia. Previous works to unravel the complex interrelationship between pain and insomnia have not explored the role of inflexible beliefs about the sleep-pain interaction, possibly due to a lack of a valid instrument for doing so. The current study evaluated the psychometric and functional properties of a 10-item Pain-Related Beliefs and Attitudes about Sleep (PBAS) scale.

METHODS: The PBAS scale was administered to four clinical samples of chronic pain patients with comorbid insomnia: to examine the scale's psychometric properties (n = 137), test-retest reliability (n = 26), sensitivity to treatment (n = 20), and generalizability (n = 62). All participants completed the PBAS together with validated measures of pain interference, insomnia severity, and cognitive-behavioral processes hypothesized to underpin insomnia.

RESULTS: The PBAS scale was found to be reliable, with adequate internal consistency and temporal stability. Factor analysis suggested a 2-factor solution representing beliefs about "pain as the primary cause of insomnia" and the "inevitable consequences of insomnia on pain and coping." The PBAS total score was positively correlated with scores from the Insomnia Severity Index (ISI) scale, Dysfunctional Beliefs and Attitudes about Sleep (DBAS) scale, and the Anxiety and Preoccupation about Sleep Questionnaire (APSQ). It was a significant predictor of insomnia severity and pain interference. A significant reduction in PBAS was also observed in patients after receiving a hybrid cognitive-behavioral intervention for both pain and insomnia.

CONCLUSIONS: Pain-related sleep beliefs appear to be an integral part of chronic pain patients' insomnia experience. The PBAS is a valid and reliable instrument for evaluating the role of these beliefs in chronic pain patients.