1 School of Social Work, McGill University, Montreal, QC H3A 1B9, Canada.
2 Department of Applied Human Sciences, Concordia University, Montreal, QC H3G 1M8, Canada.
3 Department of Pediatrics, School of Social Work, McGill University, Montreal, QC H3A 1B9, Canada.

Background: Foster care alumni face increased health challenges across the domains of mental and physical health, yet there is a paucity of research examining the associations between care experiences, health, and sleep quality in alumni aged 30 and above. Objectives: Our exploratory mixed-method study examined the sleep quality of North American group care leavers aged 30+ to understand whether sleep quality in adulthood is associated with earlier child welfare system experiences during childhood and adolescence. Secondly, we examined the association between sleep quality and overall concurrent health. Methods: Using a convenience sample of 41 alumni of care aged 30-85 and 16 qualitative interviews, we explored the intricate connections between group care leavers' developmental trauma, sleep quality, and health. Linear regression and qualitative content analysis were utilized to understand how sleep was related to well-being in aging care alumni. Results: Adult sleep was significantly associated with the perceived quality of their youth out-of-home placement experiences (ß = 0.421, p < 0.01), controlling for friendship support networks and demographic variables. Adult sleep quality was a significant predictor of overall health (ß = -0.328, p < 0.05). Qualitative interviews elucidated insights into the importance and linkages of child welfare system experiences, adult sleep, and well-being. Conclusions: Our research highlights the enduring association between child welfare placement experiences, and sleep functioning well into adulthood, even when accounting for contemporaneous social support and other demographic indicators. Practitioners should be inquiring directly about sleep, and future longitudinal research should delve deeper into the nature of sleep difficulties and their association with health and well-being.