Resaland 2016

Methods	Study design: Cluster‐randomised controlled trial Unit of randomisation: School N schools: 60 (30 intervention, 30 control) Intervention duration: 4 months Follow‐up: Immediately post‐intervention Unit of analysis: Children Setting: Norway Classification of weight status: Not reported Start date: April 2014 End date: June 2015
Participants	N (randomised): 229 (119 intervention, 110 control) N (analysed): 218 (117 intervention, 101 control) Age range: 10 ‐ 11 years Mean age: Intervention 10.2 ± 0.3, control 10.2 ± 0.3 Sex: Intervention 47% female, control 50% Ethnicity: Data not collected; birth place Norway: Intervention 93%, control 94% Reason for attrition: Not specific for the subgroup: moving away, no other reasons for withdrawal or drop‐out reported Attrition rates: Intervention 2%, control 8%
Interventions	Comparison: Active Smarter Kids programme versus standard practice Intervention: The Active Smarter Kids (ASK) programme comprised 3 components aimed at providing children with the opportunity to engage in 165 minutes of physical activity/week more than the control group: i) physically‐active lessons for 90 minutes/ week, conducted in the playground; physically‐active educational lessons were delivered in 3 core subjects – Norwegian (30 minutes/ week), mathematics (30 minutes/week) and English (30 minutes/week); ii) physical‐activity breaks (5 minutes/day) implemented in the classroom during academic lessons; and iii) physical‐activity homework (10 minutes/day) prepared by teachers. "In addition, pupils participated in the curriculum‐prescribed 90 minutes/week of Physical Education and the curriculum‐prescribed 45 minutes/week of physical activity. Thus, PA (165 minutes/week) and PE/PA (135 minutes/week) components provided children opportunities to engage in school‐based physical activities 300 minutes/week. The intervention was established as part of the mandatory school curriculum for all pupils attending the intervention schools." Standard practice: “normal practice” school curriculum, including usual amounts of physical activity/Physical Education, being approximately 135 minutes/week
Outcomes	1. School Achievement: Reading, numeracy, and English were measured using specific standardised Norwegian National tests designed and administrated by The Norwegian Directorate for Education and Training 2. Cognitive functions (measured but not provided): Inhibition assessed using Golden’s version of the Stroop test; cognitive flexibility using 1 verbal (Verbal fluency) and 1 nonverbal test (The Trail Making Test); working memory used a digit span test with digits both forward and backward (Wechsler Intelligence Scale for Children, 4th edition) 3. Obesity indices (measured but not provided for analysis): Weight/height: BMI; waist circumference; body fat (skinfold thickness sites ‐ biceps, triceps, subscapular, and suprailiac)
Notes	The authors kindly provided unpublished school achievement data for children with obesity or overweight Cognitive function data were not provided as the authors were in the process of publishing them The sample size calculation was based on the total study sample (participants in any weight group) Funding sources: The Research Council of Norway (ID number 221047/F40) and Sogn og Fjordane University College
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "cluster‐randomized controlled trial (cluster RCT) with a random allocation at the school level using a 1:1 ratio." Quote from the study protocol Resaland 2015: "A neutral third party (Centre for Clinical Research, Haukeland University Hospital, Norway) performed the randomization." Judgement comment: It remains unclear how the random sequence was generated.
Allocation concealment (selection bias)	Unclear risk	Judgement comment: No details reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Fifth‐grade classroom teachers in the intervention schools (I‐ schools) delivered the intervention. To support and qualify teachers to conduct the intervention, we arranged three comprehensive pre‐intervention seminars and two regional refreshing sessions during the intervention period. We also gave support via email and telephone to teachers in I‐schools. A password‐protected homepage (http://www. askstudy.no) further provided teachers in I‐schools with information, videos and content for approximately 100 PA lessons. All lessons on the homepage were developed in collaboration with I‐schools in Sogn og Fjordane County. Finally, we provided all I‐schools with equipment (e.g., laminating machines and accessories, mathematics bingo tiles, cones) necessary to support the intervention." Quote from the study protocol: "Blinding of children and schools was not possible due to the nature of the experiment."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote from the study protocol: "Blinding of children and schools was not possible due to the nature of the experiment. However, only the project management group has formal knowledge of group assignment. The data manager and statisticians are blinded to group allocation until analyses are conducted." Quote: "Academic performance in numeracy (often referred to as mathematics in the literature), reading and English was measured using standardized Norwegian national tests designed and administered by The Norwegian Directorate for Education."
Incomplete outcome data (attrition bias) All outcomes	High risk	Judgement comment: Based on the provided unpublished data, the proportion of missing data was substantially higher in the control group compared to the intervention group: maths Intervention 3%, control 7%; reading Intervention 0%, control 14%, English Intervention 0%, control 6%. No reason for missing data were provided. No imputation of missing data was performed for unpublished data
Selective reporting (reporting bias)	Low risk	Quote: "The study is registered in Clinicaltrials.gov ID nr: NCT02132494. We previously published a detailed description of the study (Resaland et al., 2015)...." Judgement comment: The authors provided unpublished academic achievement data which align with the study protocol and trial register. The authors clarified that they are working on the publication of executive function outcomes
Comparability of baseline groups	Low risk	Quote: "Table 1 shows children's baseline characteristics by group. There were no differences between I‐schools and C‐schools for any variables." Judgement comment: This quote relates to the total study sample including children with healthy weight. Visual inspection of participant characteristics with obesity or overweight (provided unpublished data) indicate a low risk of bias for comparability of the experimental groups at baseline
Cross‐contamination	Unclear risk	Quote: "ASK was a seven‐month cluster‐randomized controlled trial (cluster RCT) with a random allocation at the school level using a 1:1 ratio. Such randomization eliminated the possibility of contamination between pupils in the same school." Quote from the study protocol: "ASK teachers at the 28 I‐schools completed a report each week that described activities performed throughout the school day, the intensity of the activities (on a 1 to 3 scale) and the number of minutes allocated to physical activity/PE in each ASK session. All 29 C‐schools, at the end of the school year, completed a report that describes the activities that were performed and the estimated time allocated to physical activity/PE during the school year (minutes/week)." Judgement comment: Although this study was a cluster‐RCT, it was unclear how closely located the intervention and control schools were and whether intervention teachers had the opportunity to share their teaching approaches. Adherence of the control school to control group conditions was assessed but not reported. Restricted geographical area could mean risk of cross‐contamination. 3 dropout schools were all in the same district
Other bias	Low risk	Judgement comment: None detected