Development of the Sleep Acceptance Scale (SAS)

Keywords

acceptance - insomnia - scale construction

Introduction: Insomnia symptoms are associated with higher levels of metacognitive control. Controlled information processing interferes with a healthy sleep process by preventing cognitive deactivation, which involves diminished verbal regulation and control, and acceptance of spontaneous processes. Because general tools for measuring acceptance do not address sleep-related behaviors, the development of specific instruments is essential for studying the acceptance of sleep.

Aim: This study aimed to develop a new measure of sleep acceptance, titled Sleep Acceptance Scale (SAS), and examine its factorial structure, internal consistency, and construct validity.

Methods: The SAS was developed as a 6-item self-report questionnaire rated using a scale ranging from 1 (never) to 7 (always), such that higher scores indicate lower sleep acceptance. Data were collected from online surveys responded by 1419 participants, with and without insomnia symptoms. Participants also completed: The Hospital Anxiety and Depression Scale (HADS), Insomnia Severity Index (ISI), Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16), Acceptance and Action Questionnaire (AAQ-II), and Sleep Problem Acceptance Questionnaire (SPAQ). We conducted a parallel analysis and exploratory factor analysis to estimate the number of facets underlying the instrument items. Then, we ran a confirmatory factor analysis to obtain fit statistics and parameter estimates. Reliability indices for each of the facets were obtained using Cronbach's α and McDonald's ω. We assessed construct validity by examining the relations with variables known to be linked with insomnia.

Results: Mean age was 38.6 ± 9.8 years. Our sample included 1141 women and 1084 participants with insomnia symptoms. The parallel analysis procedure indicated two latent factors: avoidance (two items) and distress (four items). The 2-factor model showed a good fit [χ^2(8) = 59.48, RMSEA = 0.067 [0.05, 0.084]; CFI = 0.999; RNI = 0.999; TLI = 0.998] and factor loadings ranging from 0.55 to 0.95. Internal consistency was suboptimal for avoidance (α = 0.53 [0.48, 0.58], ω = 0.55 [0.52, 0.6]) and excellent for distress (α = 0.93 [0.93, 0.94], ω = 0.93 [0.93, 0.94]). The SAS was positively correlated with ISI (r = 0.8), DBAS-16 (r = 0.76), AAQ-II (r = 0.63), HADS-A (r = 0.64), HADS-D (r = 0.56), and negatively correlated with SPAQ (r = -0.63).

Conclusions: Preliminary evidence suggests that the SAS is a valid tool to assess acceptance of sleep.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
15 June 2023