title: Delayed high school start times later than 8:30am and impact on graduation rates and attendance rates.
abstract: The first purpose of this study was to investigate changes in high school graduation rates with a delayed school start time of later than 8:30am. The second aim of the study was to analyze the association between a delayed high school start time later than 8:30am and attendance rates.
  
  
  
  In the current study, a pre-post design using a repeated-measures analysis of variance was used to examine changes in attendance and graduation rates 2 years after a delayed start was implemented.
  
  
  
  Public high schools from 8 school districts (n=29 high schools) located throughout 7 different states. Schools were identified using previous research from the Children's National Medical Center's Division of Sleep Medicine Research Team.
  
  
  
  A total membership of more than 30,000 high school students enrolled in the 29 schools identified by the Children's National Medical Center's Research Team. A pre-post design was used for a within-subject design, controlling for any school-to-school difference in the calculation of the response variable. This is the recommended technique for a study that may include data with potential measurement error.
  
  
  
  Findings from this study linked a start time of later than 8:30am to improved attendance rates and graduation rates.
  
  
  
  Attendance rates and graduation rates significantly improved in schools with delayed start times of 8:30am or later. School officials need to take special notice that this investigation also raises questions about whether later start times are a mechanism for closing the achievement gap due to improved graduation rates.
authors.affiliation: Educational Leadership, Policy, and Instructional Technology, Central Connecticut State University, New Britain, CT. Electronic address: pamelamckeever@sbcglobal.net.
authors.forename: Pamela Malaspina
authors.initials: PM
authors.lastname: McKeever
authors.affiliation: Educational Leadership, Policy, and Instructional Technology, Central Connecticut State University, New Britain, CT.
authors.forename: Linda
authors.initials: L
authors.lastname: Clark
mesh_terms: D000041:Absenteeism; D000293:Adolescent; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D012574:Schools / Q000706:statistics & numerical data*; D012890:Sleep / Q000502:physiology*; D013334:Students / Q000523:psychology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology
keywords: Adolescent sleep; Attendance rates; Delayed school start times; Graduation completion; Graduation rates; High school bell times; Inadequate sleep; Insufficient sleep; Student social–emotional health