Katherine Wilson|Alison L. Miller|Julie C. Lumeng|Ronald D. Chervin
Sleep Environments and Sleep Durations in a Sample of Low-Income Preschool Children
California Center for Sleep Disorders|University of Michigan–Ann Arbor|California Center for Sleep Disorders
free accessnapssleep environments sleep durations sample lowincome preschool children katherine e wilson md ms alison l miller phd julie c lumeng md ronald chervin md ms faasm katherine e wilson md ms sleep disorders center department neurology alison l miller phd center human growth development department health education health behavior school public health julie c lumeng md center human growth development department pediatrics communicable diseases university michigan ann arbor mi ronald chervin md ms faasm address correspondence ronald chervin md ms michael aldrich sleep disorders laboratory 1500 e medical center dr spc 5845 ann arbor mi 48109 email address email protected sleep disorders center department neurology published onlinemarch 15 2014httpsdoiorg105664jcsm3534cited by43sectionsabstractpdf shareshare onfacebooktwitterlinkedinredditemail toolsadd favoritesdownload citationstrack citations aboutabstractstudy objectivessleep duration commonly studied children less known potential impact adverse sleep environments particularly preschool ages examined frequency suboptimal sleep environments tested associations sleep duration nocturnal sleep time among lowincome preschool childrenmethodsparents head start preschoolers michigan detroit greater lansing completed questionnaires childrens sleep schedules sleep environments respondents indicated often children slept place bright loud cold hot scale 1 never 5 always suboptimal sleep environment sse defined one conditions reported 12 nightsweek weeknight sleep duration reported time child went sleep regressed sse explanatory variable adjustment age raceethnicity gender maternal education average daily nap durationresultsamong 133 preschool children mean age 41 05 sd 48 male 39 white 52 black 34 parents high school degree parents reported 26 20 children slept sse 12 nights per week regression models sse associated 27 minutes shorter sleep duration 045 se 022 p 0044 22 minutes later time child fell asleep 037 se 019 p 0048 weeknightsconclusionsamong head start preschool children environmental challenges adequate sleep uncommon may consequences clinician preschool assessment sleep environments may open opportunities improve sleep early agescitationwilson ke miller al lumeng jc chervin rd sleep environments sleep durations sample lowincome preschool children j clin sleep med 2014103299305introductionsufficient sleep critical childrens overall health growth development1 insufficient sleep associated number daytime consequences including lower cognitive performance intelligence testing teacherreported attention difficulties23 preschool children inadequate sleep linked poor school performance hyperactive behavior4 however many us children may sleep deprived problem begin even early childhood5 although sleep needs children specific ages opposed amounts sleep children actually obtain require additional study better definition many preschoolage children obtain 1113 hours sleep often recommended6minority lowincome children may particular risk shorter sleep duration could create important health disparity public health issue minority children tend sleep less white peers78 children living low socioeconomic status neighborhoods rather affluent areas likely obtain insufficient sleep8 report bedtime difficulties7 irregular bedtime routine9 context better understanding environmental factors may affect sleep duration particularly minority lowincome children would usefuldespite importance getting adequate sleep growing recognition health disparities sleep sleep habits lowincome preschoolage children remain understudied specifically impact childs basic sleep environment may sleep scarcely addressed literature knowledge two belgian studies reported childrens environmental exposure light noise home sleep1011 kahn et al found onequarter children slept environment exposure either noise light associated poor sleep10 spruyt et al reported exposure intrusive light 437 bedrooms noise 99 bedrooms however test association light noise exposure poor sleep11brief summarycurrent knowledgestudy rationale little information exists frequency potential consequences suboptimal sleep environments among lowincome preschool children us aim study examine frequency potentially challenging sleep environments test hypothesis associated shorter sleep duration later nocturnal sleep timestudy impact suboptimal sleep environments reported 20 head start preschool sample associated shorter sleep duration later sleep times clinicians inquire home sleep environments see preschool children lowincome settingsto knowledge studies investigated burden challenging sleep environments among us preschoolage children potential association sleep duration data age group could particularly important increasing evidence suggests sleep problems early ages could lasting newly emergent irreversible consequences years later1215 moreover school readiness established preschool ages lasting influence subsequent achievement1617 aimed better define frequency suboptimal sleep environments within sample lowincome preschool children michigan test associations shorter sleep duration later nocturnal sleep timemethodsgeneral study designfor crosssectional study participants recruited flyers sent home parents children enrolled head start federally funded preschool lowincome children participating sites greater lansing detroit michigan multiple recruitment efforts made including sending home flyer invitations attend monthly parent meeting learn get better night sleep child families lansing approximately half detroit families remaining detroit families received flyer welcome parents new school year announce upcoming sleep education program would coming head start later school year flyers also invited parents participate research study childs sleep detroit sites parents also recruited person head start orientation attend upcoming parent meeting either learn childs sleep welcome new school year participate research study however attendance head start orientation required subsequent study participation head start staff also encouraged attendance parent meetingsurveys sent home parents advance parent meeting also available beginning parent meeting although many parents completed surveys independently home additional time complete also given beginning meeting small minority n 7 surveys collected parent meeting prior start educational program parents provided data analyzed report provided written informed consent person upon arrival parent meeting families participated study met federal poverty guidelines none paid head start tuition survey approved university michigan institutional review board first component twophase study families could also participate assessment sleep education program parent completed initial surveys parent study received 10 gift cardparticipantssix head start sites detroit 7 sites greater lansing area participated several differences sites including 1 detroit sites urban setting whereas lansing sites rural location 2 detroit sites predominantly black whereas lansing sites white 3 detroit sites fullday programs scheduled afternoon nap incorporated program whereas lansing sites either morning afternoon halfday programs without scheduled nap school 4 lansing sites visited january february school year detroit sites visited october november school yearto eligible child enrolled one participating head start sites parent able complete written survey independently consented study english exclusion criterion child could foster child legal signer consent would state parents asked complete surveys reference youngest child currently attending head start onlyamong 294 detroit families 374 greater lansing families eligible participate total 152 families consented including 87 families detroit 30 65 families greater lansing 17 among consented 19 families excluded analyses incomplete survey responses child age child race maternal education therefore total sample size present analyses 133 families 73 detroit 60 lansing figure 1 large majority survey respondents mothers 94 lansing 86 detroitfigure 1 recruitment diagramdownload figuremeasuresa sleep environment survey created study asked parents frequently child slept specific environmental conditions loud bright hot cold appendix sleep environment questions selected based part published clinical recommendations sleep environmental factors thought important childrens sleep1 questions written 7th grade lower reading level reviewed several sleep behavioral experts community sleep educators head start staff appropriateness questions also piloted clarity approximately 100 head start parents prior use study response options never 0 nightsweek rarely 12 nightsweek occasionally 34 nightsweek frequently 56 nightsweek always 7 nightsweekparents reported typical time child fell asleep woke weekdays weekends past 2 months parents also reported weekly frequency childs daytime naps 0 12 34 56 7 days per week length typical nap basic demographic information included childs date birth gender raceethnicity maternal education levelstatistical analysisstatistical analysis performed using sas 93 sas institute cary nc primary explanatory variable analyses sleep environment create single sleep environment variable response options 4 sleep environment items dichotomized never vs rarely 12 nights per week children categorized comparatively suboptimal sleep environment 1 4 questions answered affirmatively reduction manner binary variable performed ordinal scale would highly skewed targeted sensitive cutpoint part ensure sample affected children would prove small analysis primary outcome average weeknight sleep duration calculated reported times child fell asleep woke weeknights weekdays focused present analysis weeknight sleep duration time child fell asleep weeknights secondary outcome less variability weekend schedules pertinent daytime consequences school setting weighted average daily nap duration calculated typical nap duration typical number naps per week 7ttests 2 wilcoxon tests used appropriate assess differences participant characteristics site location similarly assessed differences participant characteristics lansing sites participants head start enrollees able obtain head start program aggregate data demographic variables child gender race education level test hypotheses suboptimal sleep environment yesno associated shorter weeknight nocturnal sleep duration later time asleep weeknights first used unadjusted linear regression models sample 133 participants next adjusted models potential confounders including child age gender raceethnicity white nonhispanic vs nonwhite hispanic maternal education high school hs degree equivalent vs since nocturnal sleep duration affected daytime napping also controlled weighted average daily nap duration final adjusted modelresultstable 1 shows participant characteristics entire sample location detroit vs lansing mean child age 41 sd 05 years range 29 52 years children lansing sites older months average detroit sites p 0001 approximately half 48 children male overall 39 children white 52 black 8 biracial children lansing sites predominantly white 87 whereas children detroit sites 94 black p 0001 overall 34 mothers high school hs degreeequivalent less statistically significant difference sites half 49 mothers college education 8 2year degree 8 4year degree 2 4year degreetable 1 sample characteristics n 133 stratified site locationtable 1 sample characteristics n 133 stratified site locationaggregate data shown available lansing sites suggested survey respondents similar preschool families enrolled participating lansing head start sites regard child gender race p 005 however survey respondents educated aggregate families 63 mothers hs degree vs 49 parents hs degree p 004sleep duration scheduleson average children reported obtain 102 sd 10 h sleep weeknights 107 sd 11 h sleep weekends overall 83 children took naps mean nap duration 16 sd 10 h 34 sd 26 days per week distribution weighted average daily nap duration variable skewed right median nap time 38 min iqr 1390 min per day regard childrens sleep schedules children reported fall asleep average 2105 sd 48 min weekdays 2148 sd 60 min weekends children woke average 0718 sd 48 min weekdays slept hour later weekends waking 0830 sd 78 minas shown figure 2 parents reported child slept environment least one night per week loud 14 bright 8 hot 12 cold 3 total 20 parents reported child slept environment either loud bright hot cold 12 nights per weekfigure 2 percentage children sleeping least 12 nights per week different sleeping environmentsno statistical difference noted lansing detroitdownload figureassociation suboptimal sleep environment sleep duration nocturnal sleep timeassociations sleep environment weeknight sleep duration shown table 2 suboptimal sleep environment associated shorter sleep duration unadjusted model p 0022 well controlling child age gender raceethnicity maternal education model 1 p 0046 association persisted weighted average daily nap duration taken account children suboptimal sleep environment slept 27 fewer minutes children without suboptimal sleep environment model 2 p 0044 covariates white nonhispanic child race ethnicity associated longer weeknight sleep duration unadjusted model p 0001 model 1 p 0005 trended toward significance fully adjusted model 2 p 0059table 2 unadjusted adjusted models weeknight nocturnal sleep duration outcometable 2 unadjusted adjusted models weeknight nocturnal sleep duration outcomeassociations sleep environment time child fell asleep shown table 3 suboptimal sleep environment associated later time fall asleep unadjusted model p 0025 child age gender raceethnicity maternal education taken account model 3 p 0038 association persisted weighted average daily nap duration also taken account children suboptimal sleep environment fell asleep 22 min later children without suboptimal sleep environment model 4 p 0048 covariates white nonhispanic child raceethnicity associated earlier time fall asleep unadjusted model p 0039 variable retain significance adjusted modelstable 3 unadjusted adjusted models bedtime outcometable 3 unadjusted adjusted models bedtime outcomedetroit vs lansing site differencesa number differences sleep duration schedules noted detroit lansing sites example lansing children slept longer weeknights detroit children mean 105 vs 99 h p 0001 detroit children longer weighted average daily naps lansing children median 10 vs 03 h p 0001 lansing children also fell asleep earlier detroit children weekdays mean 2053 vs 2116 p 001 weekends mean 2152 vs 2135 p 002 lansing children also earlier rise times detroit children weekends mean 813 vs 844 p 002 significant differences sleep environments lansing detroit site differences could distinguished potential differences based race ethnicity almost students detroit black almost lansing whitediscussionthis crosssectional study 133 lowincome preschoolers southeast michigan suggests 20 sleep suboptimal sleep environment least 12 nights per week exposure associated nocturnal sleep duration 27 minutes shorter average falling asleep 22 minutes later weeknights adequate sleep duration childhood widely believed prerequisite healthy cognitive behavioral physical development data raise possibility modifiable adverse sleep environments may provide often overlooked yet worthwhile target interventionthe frequency suboptimal sleep environments found study represents first data lowincome us preschoolage children study 14 children slept environment loud least one night per week similar previous reports 99 23 belgian school children slept loud environment1011 found 8 children slept environment parents reported bright least one night per week contrast 26 44 belgian school children slept room bright1011 us lowincome preschoolage sample differs previous samples belgian schoolage children lowincome overall spruyt et al collected sleep information june surveys collected fall winter months extended daylight hours end spring may increased percentage children sleep rooms bright additionally spruyt found urban children comparison rural children higher frequency environment bright may demonstrate differences neighborhood environments belgium versus us finally belgian studies comment frequency children slept environment hot cold therefore findings add minimal existing literature topic suboptimal sleep environments childhood finding suboptimal sleep environment associated shorter sleep duration falling asleep later also extends findings spruyt et al group study previously found excessive noise light exposure associated poor sleep defined sleep onset latency longer 30 minutes least one nocturnal arousal occurring least two nightsweek10although difference half hour sleep duration time going sleep sleep latency may seem first glance substantial research consequences key neurobehavioral metabolic outcomes linked sleep suggest sleep differences magnitude based suboptimal vs better sleep environments could profound implications especially considered chronic periods time population scale1820 example one experimental study children randomized 5 days sleep extension slept 27 minutes longer average experienced improved alertness emotional lability restlessimpulsive behavior assessed teachers masked treatment group21 conversely another study boys subjected average 46 minutes sleep restriction one week showed deterioration attention speech perception executive function22we also found difference sleep patterns detroit lansing children children lansing longer nocturnal sleep duration shorter weighted average daily nap duration compared children detroit although comparisons two locations main objective study surprised find differences sleep patterns detroit lansing samples differences may reflect nap schedules full versus halfday preschool programs previously reported cultural differences naps although daytime nap typically eliminated preschool years children cultural influences may affect age daytime nap weaned9 specifically minorities tend wean daytime nap later age23 study largely black sites detroit reported daytime naps lansing sites largely whiteour study several limitations reflect challenges communitybased research children lowincome populations response rates 21 29 good setting possibly result efforts maximize participation however respondents still represented minority targeted families overall sample size limited study restricted lowincome preschoolers one us state region factors limit generalizability conclusions especially socioeconomic groups ages locations survey respondents lansing compared nonrespondents educated lansing head start parents overall may well differed unmeasured characteristics however aggregate data reflected highest level education either parent survey asked highest maternal education level could account noted difference sample aggregate sample fact parents asked complete written surveys independently also may limited sample parents high enough literacy level complete surveys additionally recruitment efforts may biased sample appeal parents concerns regarding childs sleep furthermore study randomized controlled trial sleep environments findings cannot prove causality finally measures based parent reports study included reported time child falls asleep include bedtime means cannot know whether suboptimal sleep environments associated later bedtimes longer sleep latencies bedtime future studies include objective evaluation sleep latency sleep duration sleep times also sleep environments could illuminatingnonetheless current results suggest surprisingly low frequency exposure suboptimal sleep environment lowincome sample preschoolers southeast michigan time however children suboptimal sleep environments comparison peers appear risk shorter nocturnal sleep duration falling asleep later identification underlying reasons may helpful seek address health disparities sleep future studies incorporate objective measures sleep environment characteristics associated daytime consequences needed better understand issues could significant public health implications meantime amidst commonly expressed concern children obtain sufficient sleep evaluation possibility suboptimal sleep environments could offer new opportunities clinicians preschool staff identify needs improve sleep early agesdisclosure statementthis study funded michigan center integrative approaches health disparities p60 md002249 national institute minority health health disparities american sleep medicine foundation humanitarian award salary support katherine wilson funded nih training grant 5t32 ns00722230 physician scientist training award american sleep medicine foundation dr chervin received research grants nih fox foundation university michigan university michigan received support educational program philips respironics fisher paykel serves boards directors american academy sleep medicine american sleep medicine foundation american board sleep medicine associated professional sleep societies international pediatric sleep association consulted proctor gamble zansors mc3 serves section editor uptodate book editor cambridge university press serves volunteer advisory board sweet dreamzzz named patents patents pending copyrighted material related sleep disorder diagnosis assessment owned university michigan authors indicated financial conflicts interestappendixsleep environment questionnaireparents asked rate frequently child slept specific environment never alwaysplease rate often childsleeps place loud noisysleeps place brightduring summer sleeps place hotduring winter sleeps place coldreferences1 mindell ja owens jaa clinical guide pediatric sleep diagnosis management sleep problems philadelphia pa lippincott williams wilkins 2003 google scholar2 gruber r 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