Elaine K H Tham1, Hai-Yan Xu2, Xiuju Fu2, Nora Schneider3, Daniel Y T Goh4, Ngee Lek5, Rick S M Goh2, Shirong Cai6, Birit F P Broekman7. 1. Singapore Institute for Clinical Sciences, Singapore. 2. Institute of High Performance Computing, Singapore. 3. Société des Produits Nestlé SA, Nestl´e Research, Switzerland. 4. Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. 5. Department of Paediatrics, KK Women's and Children's Hospital, Singapore; Duke-NUS Medical School, National University of Singapore, Singapore. 6. Singapore Institute for Clinical Sciences, Singapore; Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore. 7. Singapore Institute for Clinical Sciences, Singapore; Department of Psychiatry, OLVG and AmsterdamUMC, VU University, Amsterdam, The Netherlands. Electronic address: b.broekman@amsterdamumc.nl.
Abstract
OBJECTIVE: This study investigates variations in night, day, and total sleep trajectories across infancy and childhood in Asian children. PARTICIPANTS: Participants consisted of a subset of 901 children, within the Growing Up in Singapore Towards healthy Outcomes cohort, which recruited 1247 pregnant women between June 2009 and September 2010. DESIGN: We used a novel conditional probabilistic trajectory model: a probabilistic model for mixture distribution, allowing different trajectory curves and model variances among groups to cluster longitudinal observations. Longitudinal sleep duration data for the trajectory analyses were collected from caregiver-reported questionnaires at 3, 6, 9, 12, 18, 24, and 54 months. RESULTS: We found 3 patterns of night sleep trajectories (n = 356): long consistent (31%), moderate consistent (41%), and short variable (28%); and 4 patterns of day sleep trajectories (n = 347): long variable (21%), long consistent (20%), moderate consistent (34%), and short consistent (25%). We also identified 4 patterns of total sleep trajectories (n = 345): long variable (19%), long consistent (26%), moderate consistent (28%), and short variable (27%). Short, moderate, and long trajectories differed significantly in duration. Children with consistent trajectories also displayed sleep patterns that were significantly more representative of typical developmental sleep patterns than children with variable trajectories. CONCLUSIONS: This is the first study to describe multiple sleep trajectories in Singaporean children and identify between-individual variability within the trajectory groups. Compared to predominantly Caucasian samples, night/total sleep trajectories were generally shorter, while day sleep trajectories were longer. Future studies should investigate how these variations are linked to different developmental outcomes.
OBJECTIVE: This study investigates variations in night, day, and total sleep trajectories across infancy and childhood in Asian children. PARTICIPANTS: Participants consisted of a subset of 901 children, within the Growing Up in Singapore Towards healthy Outcomes cohort, which recruited 1247 pregnant women between June 2009 and September 2010. DESIGN: We used a novel conditional probabilistic trajectory model: a probabilistic model for mixture distribution, allowing different trajectory curves and model variances among groups to cluster longitudinal observations. Longitudinal sleep duration data for the trajectory analyses were collected from caregiver-reported questionnaires at 3, 6, 9, 12, 18, 24, and 54 months. RESULTS: We found 3 patterns of night sleep trajectories (n = 356): long consistent (31%), moderate consistent (41%), and short variable (28%); and 4 patterns of day sleep trajectories (n = 347): long variable (21%), long consistent (20%), moderate consistent (34%), and short consistent (25%). We also identified 4 patterns of total sleep trajectories (n = 345): long variable (19%), long consistent (26%), moderate consistent (28%), and short variable (27%). Short, moderate, and long trajectories differed significantly in duration. Children with consistent trajectories also displayed sleep patterns that were significantly more representative of typical developmental sleep patterns than children with variable trajectories. CONCLUSIONS: This is the first study to describe multiple sleep trajectories in Singaporean children and identify between-individual variability within the trajectory groups. Compared to predominantly Caucasian samples, night/total sleep trajectories were generally shorter, while day sleep trajectories were longer. Future studies should investigate how these variations are linked to different developmental outcomes.