Staiano 2012

Methods	Study design: Randomised controlled trial Unit of randomisation: Adolescent stratified by gender Duration of intervention and follow‐up: 10 weeks of intervention Follow‐up: Immediately post‐intervention Unit of analysis: Adolescent Setting: Washington DC, USA Exclusion criteria: BMI < 75th percentile relative to CDC 2000 US reference growth charts Classification of weight status: Overweight: BMI ≥ 85th percentile, obese: BMI > 95th percentile relative to CDC 2000 US reference growth charts Start date: Not reported End date: Not reported
Participants	N (randomly assigned): 74 (28 in competitive group one, 27 in cooperative group, 19 in control group) N (completed): 54 (19 in each intervention group, 16 in control group) Age range: 15 ‐ 19 years, mean 16.5 years Sex: 57% female Ethnicity: All black Attrition: 27.0% (20/74) Reason for attrition: Self‐consciousness due to obesity, school truancy or dropout; school transfer; lack of interest; pregnancy; safety concerns about walking home in the dark; sports practice time conflicts; academic tutoring time conflicts, frequent headaches and an injury outside of the programme that required crutches. School administrators removed 3 students from the programme because of behavioural infractions external to the exergame intervention
Interventions	Comparison: competitive physical activity versus standard practice, co‐operative physical activity versus standard practice Interventions: Nintendo Wii EA Sports Active exergame played in competitive condition individually or in co‐operative condition in pairs for 30 to 60 minutes, 5 days a week, over a period of 10 weeks. "Fitness video game included cardio activities (e.g. inline skating), sports games (basketball, volleyball, tennis, baseball) and strength training. Exergame routine was the same for both intervention groups. Routines varied on a daily basis and gradually increased in difficulty throughout the study." "Children in the competitive group were encouraged to win by earning top scores and expending most calories each time they played. Children in the co‐operative group were encouraged to earn the highest possible score and to expend the most calories as a pair." "Children were supervised during the exergame sessions." Compliance was assessed through attendance. Standard practice: Continuation of usual school lunch or after‐school activities or both (Quote: "Control participants continued usual daily activities, such as socializing with friends, tutoring, and sports team practice")
Outcomes	Outcome 1: Cognitive function: Executive function (visual‐spatial skills, response inhibition, motor planning, visual scanning, speed, cognitive flexibility) measured using the subscales Design Fluency and Trail‐Making of the Delis‐Kaplan Executive Function System. Tests were administered by a trained researcher and were coded by 2 research assistants; a 3rd research assistant double‐coded all tests Outcome 2: Obesity indices: Body weight change: Body weight measured clothed without shoes by paediatricians and nurse practitioners at the school‐based wellness clinic. Body weight remained unadjusted for height
Notes	No sample size calculation was performed. Thus, this study might be at risk of a type two error 5 of the study participants (2 boys, 3 girls) were without obesity or overweight. However, this study was done with the intention of weight management, and the number of normal‐weight children is small when allocated into a control group and the 2 intervention groups Participants attended on average 1 exergame session a week Time point of measurement of cognitive function potentially introduced a confounding effect of acute exercise on cognitive function Funding sources: Robert Wood Johnson Foundation, Georgetown University
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (from email correspondence): "An adult research coordinator drew a number to randomly assign condition. When conditions became imbalanced due to attrition, new participants were assigned consecutively to the next available condition to maintain sample size balance."
Allocation concealment (selection bias)	Unclear risk	Quote (from email correspondence): "Participants knew that they were assigned to 1 of 2 classrooms or else to the control group, but they did not know the research aim until the disclosure period at the end of the study."
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Judgement comment: Blinding not possible in exercise intervention Quote (from email correspondence): Children "did not know the research aim until the disclosure period at the end of the study" Judgement comment: Personnel were also blinded to true purpose of the study (information obtained from email correspondence)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote (from email correspondence): "The coders and data enterers were blinded to the participant's condition"
Incomplete outcome data (attrition bias) All outcomes	High risk	Judgement comment: Analysis was performed with data when both baseline and post‐intervention data were available. Therefore, study did not account for incomplete outcome data. No information available on characteristics of missing data
Selective reporting (reporting bias)	Low risk	Judgement comment: Dissertation was assessed and all previously‐stated outcomes were reported in the article
Comparability of baseline groups	Unclear risk	Judgement comment: No formal assessment performed
Cross‐contamination	Low risk	Quote: "Children were supervised during the exergame sessions. Compliance was assessed through attendance."
Other bias	Low risk	Judgement comment: None detected