Brandalize 2011.

Methods	Controlled before‐and‐after study design
Participants	Eligibility: students had to be enrolled in public school, be in an afternoon 6th grade class in 2008, be in an afternoon or morning 7th grade class in 2009, and be between 12‐16 years old. Participants: 379 students
Interventions	Comparison of students who shifted from afternoon (13:00 to 17:30) to morning (07:30 to 12:00) classes right after the July vacation in 2009, to those that remained in afternoon classes.
Outcomes	Time in bed, wake time, and bedtime, for school days and weekends Adiposity (skinfold measurement method on triceps and medial leg skin folds) and percentage of body fat Waist circumference BMI Frequency of napping Sexual maturity Habitual physical activity Eating habits SES Outcome measurement: Sleep and SES questionnaires completed in the classroom and immediately returned to evaluators Questions regarding physical activity and eating frequency were answered at home and afterward returned to school. For BMI, waist circumference, and adiposity, three measures were taken and the average was recorded. The same evaluators took each measure for both rounds of data collection. Data collection occurred twice: between August and October 2008, and between August and October of 2009
Notes	Funding sources: supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	CBA study; high risk by definition
Allocation concealment (selection bias)	High risk	CBA study; high risk by definition
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding of participants or personnel mentioned; participants knew their start time
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Attrition was not addressed in the paper
Selective reporting (reporting bias)	Low risk	No evidence that some outcomes were not reported
Other bias	Low risk	No evidence of other biases
Similarity of baseline measures (RCT/CBA only)	Low risk	Pretest differences accounted for in analyses through use of covariates
Similarity of baseline characteristics (RCT/CBA only)	Unclear risk	No report of characteristics is given; analyses divided by sex
Diffusion of treatment effects (RCT/CBA only)	Low risk	Students were assigned to different start times; start times are not subject to diffusion as a treatment