<p><strong>STUDY OBJECTIVES: </strong>Over 75% of US high school students obtain insufficient sleep, placing them at risk for adverse health outcomes. Identification of modifiable determinants of adolescent sleep is needed to inform prevention strategies, yet little is known about the influence of the built environment on adolescent sleep.</p>

<p><strong>METHODS: </strong>In this prospective study, actigraphy was used to assess sleep outcomes among 110 adolescents for 14 days each in eighth and ninth grades: duration (hours/night), onset and offset, and sleeping ≥8 hours. Home addresses were linked to built environment exposures: sound levels, tree canopy cover, street density, intersection density, population density, and housing density. Mixed-effects regression estimated associations of built environment measures with sleep outcomes, adjusting for sex, race, parent education, household income, household size, grade, weeknight status, and neighborhood poverty.</p>

<p><strong>RESULTS: </strong>A 1-standard deviation (SD) increase in neighborhood sound was associated with 16 minutes later sleep onset (β = 0.28; 95% confidence interval (CI): 0.06, 0.49) and 25% lower odds of sleeping for ≥8 hours (odds ratio (OR) = 0.75, 95% CI: 0.59, 0.96). A 1-SD increase in neighborhood tree canopy was associated with 18 minutes earlier sleep onset (β = -0.31, 95% CI: -0.49, -0.13) and 10 minutes earlier sleep offset (β= -0.17, 95% CI: -0.28, -0.05). No associations were observed for density-based exposures.</p>

<p><strong>CONCLUSIONS: </strong>Higher neighborhood sound level was associated with lower odds of sufficient sleep, while higher tree canopy cover was associated with more favorable sleep timing. Neighborhood sound levels and tree canopy cover are potential targets for policies and interventions to support healthier sleep among adolescents.</p>

<p><strong>BACKGROUND: </strong>Pediatricians lack tools to support families at home for the promotion of childhood sleep. We are using the Multiphase Optimization Strategy (MOST) framework to guide the development of a mobile health platform for childhood sleep promotion.</p>

<p><strong>PURPOSE: </strong>Under the preparation phase of the MOST framework, to demonstrate feasibility of a mobile health platform towards treating children with insufficient sleep.</p>

<p><strong>METHODS: </strong>Children aged 10-12y were enrolled (Study #1: N=30; Study #2: N=43). Participants wore a sleep tracker to measure sleep duration. Data were retrieved by a mobile health platform, programmed to send introductory messages during run-in (2 weeks) and goal achievement messages during intervention (7 weeks) periods. In study #1, participants were randomized to control, gain-framed incentive or loss-framed incentive arms. In study #2, participants were randomized to control, loss-framed incentive, normative feedback or loss-framed incentive plus normative feedback arms.</p>

<p><strong>RESULTS: </strong>In study #1, 1,514 nights of data were captured (69%) and sleep duration during the intervention was higher by an average of 21 (95% CI: -8, 51) and 34 (95% CI: 7, 61) minutes per night for the gain-framed and loss-framed arms, respectively, compared to controls. In study #2, 2,689 nights of data were captured (81%), with no major differences in average sleep duration between the control and the loss-framed or normative feedback arms.</p>

<p><strong>CONCLUSION: </strong>We have developed and deployed a mobile health platform that can capture sleep data and remotely communicate with families. Promising candidate intervention components will be further investigated under the optimization phase of the MOST framework.</p>

<p><strong>Study Objectives: </strong>Pediatricians lack tools to support families at home for the promotion of childhood sleep. We are using the Multiphase Optimization Strategy (MOST) framework to guide the development of a mobile health platform for childhood sleep promotion. The objective of this study is to demonstrate feasibility of a mobile health platform towards treating children with insufficient sleep.</p>

<p><strong>Methods: </strong>Children aged 10-12 years were enrolled (Study #1: = 30; Study #2: = 43). Participants wore a sleep tracker to measure sleep duration. Data were retrieved by a mobile health platform, programmed to send introductory messages during run-in (2 weeks) and goal achievement messages during intervention (7 weeks) periods. In study #1, participants were randomized to control, gain-framed incentive or loss-framed incentive arms. In study #2, participants were randomized to control, loss-framed incentive, normative feedback or loss-framed incentive plus normative feedback arms.</p>

<p><strong>Results: </strong>In study #1, 1514 nights of data were captured (69%) and sleep duration during the intervention was higher by an average of 21 (95% CI: -8, 51) and 34 (95% CI: 7, 61) minutes per night for the gain-framed and loss-framed arms, respectively, compared to controls. In study #2, 2,689 nights of data were captured (81%), with no major differences in average sleep duration between the control and the loss-framed or normative feedback arms.</p>

<p><strong>Conclusions: </strong>We have developed and deployed a mobile health platform that can capture sleep data and remotely communicate with families. Promising candidate intervention components will be further investigated under the of the MOST framework.</p>

<p><strong>Clinical Trials: </strong>Both studies included in this manuscript were registered at clinicaltrials.gov:-Study #1: NCT03263338-Study #2: NCT03426644.</p>

<p><strong>PURPOSE: </strong>The purpose of the study was to quantify changes in sleep during the middle-to-high school transition and determine if changes in sleep differ by sociodemographic characteristics.</p>

<p><strong>METHODS: </strong>Adolescents were enrolled in eighth grade and followed into ninth grade (N&nbsp;= 110; 2,470 nights observed). The outcomes were actigraphy-estimated sleep duration, sleep onset, sleep offset, and sleep sufficiency (≥8&nbsp;hours of sleep). The exposures were school grade (eighth or ninth), school night status (school or nonschool), sex (female or male), and race (white, black, or other).</p>

<p><strong>RESULTS: </strong>On school nights, sleep duration declined by 25.8&nbsp;minutes per night (p &lt; .001) from eighth to ninth grade. There was no change in sleep duration on nonschool nights. Timing of sleep onset was 22.2&nbsp;minutes later on school nights (p &lt; .001) and 17.4&nbsp;minutes later on nonschool nights (p&nbsp;&lt;&nbsp;.001) in ninth grade. Timing of sleep offset did not change on school mornings but was 22.2&nbsp;minutes later on nonschool mornings (p &lt; .001) in ninth grade. The proportion of school nights (and nonschool nights) with sleep duration ≥8&nbsp;hours was 9.4% (38.3%) in eighth grade and 5.7% (35.9%) in ninth grade. The odds of sleeping ≥8&nbsp;hours per night was 42% lower in ninth grade, compared toeighth grade (odds ratio&nbsp;= .58; 95% confidence interval: .37, .91). Males were 59% less likely to sleep ≥8&nbsp;hours per night. Black adolescents were 51% less likely to sleep ≥8&nbsp;hours per night.</p>

<p><strong>CONCLUSIONS: </strong>Insufficient sleep is highly prevalent, especially on school nights and among male and black adolescents, and this problem worsens with the transition to high school.</p>

<p>We previously reported significant gains in pQCT measures of tibia trabecular bone mineral density (BMD) and cortical structure following completion of therapy in children and adolescents with acute lymphoblastic leukemia (ALL). The objective of this study was to examine changes in DXA measures used in clinical practice and expressed as Z-scores using robust national reference data. Children and adolescents, ages 5 to 18 years were enrolled within 2 (median 0.8) years of completing ALL therapy. DXA total-body less-head bone mineral content (TBLH-BMC), and spine, total hip, femoral neck, and 1/3rd radius areal BMD (aBMD) were assessed in 45 participants at enrollment and 12-months later. Linear regression models examined correlates of changes in DXA Z-scores. Changes in DXA outcomes were compared to changes in tibia pQCT trabecular and cortical volumetric BMD (vBMD) and cortical area. At enrollment, DXA TBLH-BMC, spine and radius aBMD Z-scores were not significantly reduced in ALL survivors; however, total hip [median -0.74 (IQ range -1.51 to -0.04)] and femoral neck [-0.51 (-1.24 to 0.14)] aBMD Z-scores were lower (both p &lt; 0.01) compared to reference data. DXA Z-scores at all skeletal sites increased over 12 months. Despite improvement, total hip Z-score remained lower at -0.55 (-1.05 to 0.18). The increases in TBLH-BMC, total hip and femoral neck aBMD Z-scores were more pronounced in those enrolled within 6 months of completing ALL therapy, compared to those enrolled at &gt;6 months. Gains in TBLH-BMC, total hip, femoral neck and radius aBMD Z-scores were significantly associated with gains in tibia cortical area Z-scores (R = 0.56 to 0.67, p ≤ 0.001). Changes in TBLH and proximal femur sites were associated with gains in trabecular vBMD Z-scores (R = 0.37 to 0.40; p ≤ 0.01); these associations were not significant when adjusted for gains in cortical area. In summary, gains in DXA measures were most pronounced in total hip and femoral neck following ALL therapy. The gains in all DXA measures, with the exception of lumbar spine, reflected gains in cortical area. Overall, ALL survivors demonstrate skeletal recovery following completion of therapy; a small sub-group continue to demonstrate deficits and benefit from continued observation to ensure improvement over time.</p>