CARDIA sleep ancillary study: study design and methods

Area of Science:

• Sleep science
• Circadian biology
• Health disparities research

Background:

• Sleep and circadian disturbances are prevalent, disproportionately affecting Black individuals compared to White individuals.
• Understanding these disparities is crucial for public health initiatives.
• The Coronary Artery Disease in Young Adults (CARDIA) study provides a valuable cohort for investigating these differences.

Purpose of the Study:

• To describe the study design and methodology for an ancillary sleep study within the CARDIA cohort.
• To lay the groundwork for future analyses examining determinants of sleep and circadian disparities between Black and White adults.
• To collect comprehensive data on sleep patterns, quality, and environmental factors.

Main Methods:

• An observational, ancillary study conducted in two phases during the CARDIA Year 35 examination.
• Phase 1 utilized questionnaires for chronotype, restless legs syndrome, and sleep environment.
• Phase 2 incorporated questionnaires for sleep quality, daytime sleepiness, insomnia, wrist actigraphy, and home sleep apnea testing. A subset underwent objective environmental monitoring (light, temperature, sound).

Main Results:

• Sample sizes varied by assessment: 2200-2400 for Phase 1 questionnaires, 899 for wrist actigraphy, and 619 for sleep apnea tests.
• Data collected include subjective sleep measures, objective sleep-wake patterns, and environmental exposures.
• The study successfully gathered diverse sleep-related data from a large cohort.

Conclusions:

• The described methodology provides a robust foundation for examining sleep and circadian disparities in a diverse adult population.
• The collected data will be integrated into the CARDIA dataset, enabling future research on the determinants of racial disparities in sleep.
• This study design facilitates a deeper understanding of the complex factors influencing sleep health across different racial groups.