Concordance in parent-child and sibling actigraphy-measured sleep: Evidence among early adolescent twins and primary caregivers.

Study Objectives: Growing evidence suggests concordance between parent and youth sleep. However, no known study has simultaneously examined concordance among siblings' sleep patterns. This study investigated daily and average concordance in (1) parent-youth and (2) sibling actigraphy-measured sleep, as well as the degree to which sibling concordance varied by sleeping arrangements.

Methods: 516 twin siblings (M = 10.74, 51% female; 30% monozygotic (MZ) twin pairs, 37% same-sex dizygotic pairs (DZ-ss), 33% opposite-sex DZ pairs (DZ-os)) and their primary caregivers (M = 40.59, 95% female) wore wrist-based accelerometers for 7 consecutive nights to measure sleep duration, efficiency, midpoint time, and latency. Primary caregivers also reported on demographics, youth pubertal status, and room-sharing. Two-level multilevel models were estimated to examine daily and average concordance in parent-youth and sibling sleep.

Results: Daily concordance was observed between parent and youth sleep duration and midpoint; average concordance was found for sleep duration, midpoint, and latency. Within sibling dyads, daily and average concordance was evident across all sleep parameters (duration, efficiency, midpoint, latency), with generally stronger concordance patterns for MZ than DZ twin pairs, and for twins who shared a room with their co-twin.

Conclusions: This is the first known study to document concordance among parent-youth and siblings' actigraphy-measured sleep within the same study (i.e., triad). Our findings can help inform the development of family-level interventions targeting daily and overall sleep hygiene.