Development of the Dysfunctional Beliefs about Sleep for shift Workers scale (DBSW) for shift-working registered nurses.

Introduction: We aimed to develop a sleep-related dysfunctional beliefs scale that can be applied specifically to shift workers.

Methods: The Dysfunctional Beliefs about Sleep for shift Workers scale (DBSW) was developed under the standard rating scale development process. We conducted two online surveys to run an exploratory factor analysis (EFA, Study I,  = 323) and a confirmatory factor analysis (CFA, Study II,  = 300) for the new scale. The convergent validity of the DBSW was explored with pre-existing rating scales, including the Dysfunctional Beliefs and Attitudes about Sleep-16 scale (DBAS-16), Insomnia Severity Index (ISI), and Glasgow Sleep Effort Scale (GSES).

Results: We finally selected 10 items after EFA, and we observed that the scale has three factors. Based on the CFA, the three-factor model with a 10-item DBSW showed good fits for the model (CFI = 0.971, TLI = 0.959, RMSEA = 0.050, SRMR = 0.042). The internal consistency of reliability of the DBSW were excellent based on the McDonald's omega value of 0.802. Convergent validity analyses revealed significant correlations between the total DBSW score and ISI ( = 0.54,  < 0.01), DBAS-16 ( = 0.74,  < 0.01), and GSES ( = 0.48,  < 0.01). Three factors (Dysfunctional beliefs, Control, and Shift work) of the DBSW were correlated with each other: total score of DBSW, ISI, DBAS-16, and GSES scores.

Conclusions: The DBSW is a rating scale that can measure sleep-related cognition specific to shift workers with good reliability and validity.