The National Sleep Foundation's Sleep Health Index

Objectives: A validated survey instrument to assess general sleep health would be a useful research tool, particularly when objective measures of sleep are not feasible. Thus, the National Sleep Foundation spearheaded the development of the Sleep Health Index (SHI).

Design: The development of the SHI began with a task force of experts who identified key sleep domains and questions. An initial draft of the survey was created and questions were refined using cognitive testing and pretesting. The resulting 28-question survey was administered via random-sample telephone interviews to nationally representative samples of adults in 2014 (n=1253) and 2015 (n=1250). These data were combined to create the index. A factor analysis linked 14 questions to 3 discrete domains: sleep quality, sleep duration, and disordered sleep. These were assembled as sub-indices, then combined to form the overall SHI, with scores ranging from 0 to 100 (higher score reflects better sleep health).

Results: Americans earned an overall SHI score of 76/100, with sub-index scores of 81/100 in disordered sleep, 79/100 in sleep duration, and 68/100 in sleep quality. In regression analyses, the strongest independent predictors of sleep health were self-reported stress (β=-0.26) and overall health (β=0.26), which were also the strongest predictors of sleep quality (β=-0.32 and β=0.27 respectively).

Conclusions: The current 12-item SHI is a valid, reliable research tool that robustly measures 3 separate but related elements of sleep health-duration, quality, and disorders-and assesses the sleep health status of adults in the United States.