Quantifying impact of real-world barriers to sleep: The Brief Index of Sleep Control (BRISC)

Objective: Lack of control over sleep may contribute to population-level sleep disturbances, yet relatively little work has explored the degree to which an individual's sense of control over their sleep may represent an important factor. Methods: Data from the Sleep and Healthy Activity Diet Environment and Socialization (SHADES) study, conducted in the Philadelphia area on a population comprising 1,007 individuals aged 22-60 years, was used. The BRief Index of Sleep Control (BRISC) was developed to quantify the degree to which an individual has control over their sleep. Reliability of the BRISC was assessed using Cronbach's alpha. Convergent validity was assessed by examining age-adjusted items and total score relationships to insomnia (ISI), sleepiness (ESS), sleep quality (PSQI), and total sleep time (NHANES). Results: After adjustment for covariates, greater control over sleep was associated with a lower PSQI score (B = -2.2, 95% CI [-2.4,-2.0], P <.0001), lower ISI score (B = -3.1, 95% CI [-3.5,-2.7], P <.0001), lower ESS score (B=-1.4, 95% CI [-1.7,-1.1], P <.0001), and more hours of sleep duration (B = 0.5, 95% CI [0.4,0.6], P <.0001). Each BRISC item was separately associated with each sleep outcome (P <.0001), although the items were not collinear with each other (all R<0.7). Thus, the BRISC instrument demonstrated high reliability and good validity. Conclusions: Control over sleep may represent an important factor in sleep health. Control over time to bed, time awake, sleep duration, and sleep quality are all related to sleep outcomes and assessment of these constructs may be useful for future sleep interventions.