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What does research reveal about later school start times for high schools?

June 2017

Following an established REL Northeast & Islands research protocol, we conducted a search for recent research on delayed start times for high schools. We focused on identifying resources that specifically addressed research on the various impacts of delayed high school start times, such as student academic achievement, sleep duration, attendance, and motor vehicle accidents. The sources searched included ERIC and other federally funded databases and organizations, academic research databases, and general Internet search engines (For details, please see the methods section at the end of this memo.)

We have not evaluated the quality of references and the resources provided in this response and we offer them only for your reference. Also, we searched the references in the response from the most commonly used resources of research, but they are not comprehensive and other relevant references and resources may exist.

Research References

  1. Carrell, S. E., T. Maghakian, and J. E. West. (2011). “A’s From ZZZZ’s? The Causal Effect of School Start Time on the Academic Achievement of Adolescents.” American Economic Journal 3 (3): 62–71
    From the abstract: “Recent sleep research finds that many adolescents are sleep-deprived because of both early school start times and changing sleep patterns during the teen years. This study identifies the causal effect of school start time on academic achievement by using two policy changes in the daily schedule at the US Air Force Academy along with the randomized placement of freshman students to courses and instructors. Results show that starting the school day 50 minutes later has a significant positive effect on student achievement, which is roughly equivalent to raising teacher quality by one standard deviation.”
  2. McKeever, P. M., & Clark, L. (2017). Delayed high school start times later than 8: 30am and impact on graduation rates and attendance rates. Sleep Health, 3(2), 119-125.
    DOC Link:
    From the 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 8:30 a.m. The second aim of the study was to analyze the association between a delayed high school start time later than 8:30 a.m. and attendance rates. A pre-post design using a repeated measures Analysis of Variance (ANOVA) was used to examine changes in attendance and graduation rates two years after a delayed start was implemented. Public high schools from eight school districts (n = 29 high schools) located throughout seven different states were identified as subjects for the study using previous research from the Children’s National Medical Center’s (CNMC) Division of Sleep Medicine Research Team. Findings from this study showed that attendance rates and graduation rates significantly improved in schools with delayed start times of 8:30 a.m. 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.”
  3. Owens, Judith A., Katherine Belon, and Patricia Moss. (2010). "Impact of Delaying School Start Time on Adolescent Sleep, Mood, and Behavior." Archives of Pediatrics and Adolescent Medicine, 164(7): 608-14.
    From the abstract: “Researchers sought to examine the impact of a 30-minute delay in school start time (from 8:00 AM to 8:30 AM) on adolescents’ sleep, mood, and behavior. Participants were high school students in grades 9 to 12 (n = 201) at an independent high school in Rhode Island. Students completed the online retrospective Sleep Habits Survey before and after the change in school start time. After the start time delay, mean school night sleep duration increased by 45 minutes, and average bedtime advanced by 18 minutes (95% confidence interval, 7-29 minutes [t423 = 3.36; P < .001]); the percentage of students getting less than 7 hours of sleep decreased by 79.4%, and those reporting at least 8 hours of sleep increased from 16.4% to 54.7%. Students reported significantly more satisfaction with sleep and experienced improved motivation. Daytime sleepiness, fatigue, and depressed mood were all reduced. Most health-related variables, including Health Center visits for fatigue-related complaints, and class attendance also improved. Researchers concluded that a modest delay in school start time was associated with significant improvements in measures of adolescent alertness, mood, and health. The results of this study support the potential benefits of adjusting school schedules to adolescents' sleep needs, circadian rhythm, and developmental stage.”
  4. Paksarian D, Rudolph KE, He JP, Merikangas KR. (2015). School start time and adolescent sleep patterns: Results from the US national comorbidity survey-adolescent supplement. Am J Public Health. 105:1351–7. doi: 10.2105/ AJPH.2015.302619
    From the abstract: “We estimated associations between school start time and adolescent weeknight bedtime, weeknight sleep duration, and weekend compensatory sleep and assessed whether associations differ by age, sex, or urbanicity. We used a subsample of a nationally representative, cross-sectional survey of 7308 students aged 13 to 18 years attending 245 schools to estimate associations of school start time, reported by school principals, with weeknight bedtime and sleep duration and weekend compensatory sleep, reported during adolescent face-to-face interviews. Start time was positively associated with weeknight bedtime. Associations between start time and weeknight sleep duration were nonlinear and were strongest for start times of 8:00 am and earlier. Associations differed by sex and urbanicity, with the strongest association among boys in major metropolitan counties. Start time was negatively associated with sleep duration among boys in nonurban counties. Start time was not associated with weekend compensatory sleep. Positive overall associations between school start time and adolescent sleep duration at the national level support recent policy recommendations for delaying school start times. However, the impact of start time delays may differ by sex and urbanicity.”
  5. Perkinson-Gloor N, Lemola S, Grob A. (2013). Sleep duration, positive attitude toward life, and academic achievement: the role of daytime tiredness, behavioral persistence, and school start times. J Adolesc. 36:311–318.
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    From the abstract: “Sleep timing undergoes profound changes during adolescence, often resulting in inadequate sleep duration. The present study examines the relationship of sleep duration with positive attitude toward life and academic achievement in a sample of 2716 adolescents in Switzerland (mean age: 15.4 years, SD ¼ 0.8), and whether this relationship is mediated by increased daytime tiredness and lower self-discipline/behavioral persistence. Further, we address the question whether adolescents who start school modestly later (20 min; n ¼ 343) receive more sleep and report better functioning. Sleeping less than an average of 8 h per night was related to more tiredness, inferior behavioral persistence, less positive attitude toward life, and lower school grades, as compared to longer sleep duration. Daytime tiredness and behavioral persistence mediated the relationship between short sleep duration and positive attitude toward life and school grades. Students who started school 20 min later received reliably more sleep and reported less tiredness.”
  6. Thacher PV, Onyper SV. (2016). Longitudinal outcomes of start time delay on sleep, behavior, and achievement in high school. SLEEP. 39(2):271–281
    From the abstract: “We sought to establish whether sleep, health, mood, behavior, and academics improved after a 45-minute delay in high school start time, and whether changes persisted longitudinally. We collected data from school records and student self-report across a number of domains at baseline (May 2012) and at two follow-up time points (November 2012 and May 2013), at a public high school in upstate New York. Students enrolled during academic years (AY) 2011–2012 and 2012–2013 completed the Pittsburgh Sleep Quality Index; the DASS-21; the “Owl-Lark” Scale; the Daytime Sleepiness Index; and a brief self-report of health. Reports from school records regarding attendance, tardiness, disciplinary violations, and academic performance were collected for AY 2010–2011 through 2013–2014. Students delayed but did not extend their sleep period; we found lasting improvements in tardiness and disciplinary violations after the start-time delay, but no changes to other variables. At the first follow-up, students reported 20 minutes longer sleep, driven by later rise times and stable bed times. At the second follow-up, students maintained later rise times but delayed bedtimes, returning total sleep to baseline levels. A delay in rise time, paralleling the delay in the start time that occurred, resulted in less tardiness and decreased disciplinary incidents, but larger improvements to sleep patterns may be necessary to affect health, attendance, sleepiness, and academic performance. Later start times improved tardiness and disciplinary issues at this school district. A delay in start time may be a necessary but not sufficient means to increase sleep time and may depend on preexisting individual differences.”
  7. Vollmer, C., Pötsch, F., & Randler, C. (2013). Morningness is associated with better gradings and higher attention in class. Learning and Individual Differences, 27, 167–173. etter_gradings_and_higher_attention_in_class
    From the abstract: “There are individual preferences in circadian rhythm, also known as chronotype, ranging from morning-orientation to evening-orientation. In adolescence, the sleep rhythm shifts from morningness to eveningness while school schedules are early. School performance – short-term attention and gradings – may decrease with increasing evening-orientation. One thousand nine hundred and seventy-seven adolescents aged 10– 17 provided self-reported information on their chronotype as well as their gradings and completed an attention test. Controlling for age and gender, earlier chronotype was a significant predictor of better gradings and better performance in the attention test. Moreover, concerning the attention test, we found a slower and more considerate completion strategy in morning-types and faster and a more impulsive strategy in evening-types. Using structural equation modeling, age had a negative influence while class level had a positive influence on gradings and attention. The authors suggest a delay of school start times by 1 h as a measure to improve the school performance of late chronotypes.”
  8. Wahlstrom, K., Dretzke, B., Gordon, M., Peterson, K., Edwards, K., & Gdula, J. (2014). Examining the Impact of Later High School Start Times on the Health and Academic Performance of High School Students: A Multi-Site Study. Center for Applied Research and Educational Improvement; St Paul, MN: University of Minnesota.
    From the abstract: “The results from this three-year research study, conducted with over 9,000 students in eight public high schools in three states, reveal that high schools that start at 8:30 AM or later allow for more than 60% of students to obtain at least eight hours of sleep per school night. Teens getting less than eight hours of sleep reported significantly higher depression symptoms, greater use of caffeine, and are at greater risk for making poor choices for substance use. Academic performance outcomes, including grades earned in core subject areas of math, English, science and social studies, plus performance on state and national achievement tests, attendance rates and reduced tardiness show significantly positive improvement with the later start times of 8:35 AM or later. Finally, the number of car crashes for teen drivers from 16 to 18 years of age was significantly reduced by 70% when a school shifted start times from 7:35 AM to 8:55 AM.”


Keywords and Search Strings

The following keywords and search strings were used to search the reference databases and other sources:

Later high school start time

Delayed start time high school

“High School start time” AND “academic achievement” OR “sleep”

Databases and Resources

We searched ERIC for relevant resources. ERIC is a free online library of over 1.6 million citations of education research sponsored by the Insititute of Education Sciences. Additionally, we searched Google Scholar and PsychInfo.

Reference Search and Selection Criteria

When we were searching and reviewing resources, we considered the following criteria:

Date of the publication: References and resources published for last 15 years, from 2002 to present, were included in the search and review.

Search Priorities of Reference Sources: Search priority is given to study reports, briefs, and other documents that are published and/or reviewed by IES and other federal or federally funded organizations, academic databases, including WWC, ERIC, and NCEE

Methodology: Following methodological priorities/considerations were given in the review and selection of the references: (a) study types – randomized control trials, quasi experiments, surveys, descriptive data analyses, literature reviews, policy briefs, etc., generally in this order (b) target population, samples (representativeness of the target population, sample size, volunteered or randomly selected, etc.), study duration, etc. (c) limitations, generalizability of the findings and conclusions, etc.

This memorandum is one in a series of quick-turnaround responses to specific questions posed by educational stakeholders in the Northeast & Islands Region (Connecticut, Maine, Massachusetts, New Hampshire, New York, Puerto Rico, Rhode Island, US Virgin Islands, and Vermont), which is served by the Regional Educational Laboratory Northeast & Islands at Education Development Center. This memorandum was prepared by REL Northeast & Islands under a contract with the U.S. Department of Education’s Institute of Education Sciences (IES), Contract ED-IES-17-C-0008, administered by Education Development Center. Its content does not necessarily reflect the views or policies of IES or the U.S. Department of Education nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.