Elizabeth L Adams1, Lindsay Master2, Orfeu M Buxton3, Jennifer S Savage4. 1. Center for Childhood Obesity Research, Penn State University, University Park, PA, United States; Department of Nutrition Sciences, Penn State University, University Park, PA, United States. Electronic address: eka5159@psu.edu. 2. Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, United States. Electronic address: lmaster@psu.edu. 3. Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, United States; Department of Social and Behavioral Sciences, Harvard Chan School of Public Health, Boston, MA, United States; Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States; Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States. Electronic address: orfeu@psu.edu. 4. Center for Childhood Obesity Research, Penn State University, University Park, PA, United States; Department of Nutrition Sciences, Penn State University, University Park, PA, United States. Electronic address: jfs195@psu.edu.
Abstract
OBJECTIVE/ BACKGROUND: We describe developmental and day-to-night sleep patterns across the first six months of life using actigraphy and compare these to mother-reported perceptions of infant sleep. PATIENTS/ METHODS: This observational, burst design included three, one-week bursts of data collection at six, 15, and 24 weeks of age. Infants wore an actigraphy device (Actiwatch Spectrum) on their right ankle for each one-week period. Data were scored using a SAS-based hierarchical, algorithmic methodology and independently assessed for necessary corrections by two trained scorers in a Visual Basic. Mothers completed the Brief Infant Sleep Questionnaire (BISQ) at each burst. Mixed models tested developmental patterns over time and multilevel models examined day-to-night sleep patterns at each burst. RESULTS: Daytime nap sleep duration decreased over time (p = 0.02) with marginal significance for nighttime sleep interval duration increasing over time (p = 0.09). Total 24-h sleep duration was time invariant (p > 0.05). These longitudinal patterns were similar when examining mothers' perception of infant sleep. Daily variations demonstrated nighttime sleep interval and maintenance efficiency did not predict next-day nap sleep duration. Yet, at 24 weeks of age, daytime nap sleep was associated with that nights' sleep interval. For every 1-h above infants' average total daytime nap sleep duration, infants slept ∼15 min longer and 1.0% less efficiently that night (p ≤ 0.05). Mothers overestimated daytime nap sleep and total 24-h sleep, when compared to actigraphy (p < 0.01). CONCLUSION: Changes to infants' usual daytime sleep duration impacted subsequent sleep bouts and mothers tended to overestimate infants' sleep. These patterns should be explored in relation to parenting practices.
OBJECTIVE/ BACKGROUND: We describe developmental and day-to-night sleep patterns across the first six months of life using actigraphy and compare these to mother-reported perceptions of infant sleep. PATIENTS/ METHODS: This observational, burst design included three, one-week bursts of data collection at six, 15, and 24 weeks of age. Infants wore an actigraphy device (Actiwatch Spectrum) on their right ankle for each one-week period. Data were scored using a SAS-based hierarchical, algorithmic methodology and independently assessed for necessary corrections by two trained scorers in a Visual Basic. Mothers completed the Brief Infant Sleep Questionnaire (BISQ) at each burst. Mixed models tested developmental patterns over time and multilevel models examined day-to-night sleep patterns at each burst. RESULTS: Daytime nap sleep duration decreased over time (p = 0.02) with marginal significance for nighttime sleep interval duration increasing over time (p = 0.09). Total 24-h sleep duration was time invariant (p > 0.05). These longitudinal patterns were similar when examining mothers' perception of infant sleep. Daily variations demonstrated nighttime sleep interval and maintenance efficiency did not predict next-day nap sleep duration. Yet, at 24 weeks of age, daytime nap sleep was associated with that nights' sleep interval. For every 1-h above infants' average total daytime nap sleep duration, infants slept ∼15 min longer and 1.0% less efficiently that night (p ≤ 0.05). Mothers overestimated daytime nap sleep and total 24-h sleep, when compared to actigraphy (p < 0.01). CONCLUSION: Changes to infants' usual daytime sleep duration impacted subsequent sleep bouts and mothers tended to overestimate infants' sleep. These patterns should be explored in relation to parenting practices.