Ickovics 2019.

Study characteristics
Methods	Study design: cluster‐RCT
Participants	School inclusion criteria: K through 8 district schools New Haven, Connecticut School exclusion criteria: — Student inclusion criteria: students enrolled in Grade 5 when the study began or began attending a target school in Grade 6 Student exclusion criteria: — Setting: school, urban Age group: children Gender distribution: females and males Country where trial was performed: USA
Interventions	Intervention 1: PA only Intervention 2: Nutrition + PA All schools received $500/y to establish a School Wellness team, focused on written policy implementation relevant to randomised condition. Research staff supported schools with 1 to 2 visits per month to provide workshops  PA: high‐quality PE class at least 90 minutes/week to foster a lifelong appreciation for physical fitness and to participate in fitness activities; promotion of active transport; integration of PA into the classroom; fitness challenges. PA will not be used as a form of punishment (e.g. running laps, withholding recess), distribution of activity monitors, use of online tracking software, family‐targeted newsletters Nutrition: appealing and attractive meals, clean and pleasant setting, no fried vegetables, only low‐fat, non‐flavoured milk, whole‐grain cereals. Schools will not use food or beverages as rewards or punishments, and will limit celebrations involving food to once per month and with only 1 food or beverage that does not meet school nutrition standards. Nutrition education provided through parent workshops, student materials, school menus, and bulletins. Schools asked to engage parents and students in thorough taste testing of new menu options and to assist with selecting food Comparator 1: nutrition intervention only Comparator 2: delayed control; schools received other health‐relevant training (e.g. oral health, cold or influenza prevention) during the study period, with obesity‐related materials delivered at study completion Duration of intervention: 3 years Duration of follow‐up: annually for 3 years Number of schools: 12 Theoretical Framework: —
Outcomes	BMI
Study registration	NCT02043626 (retrospectively registered)
Publication details	Language of publication: English  Funding: non‐commercial funding (research funding body) Publication status: peer‐reviewed journal
Stated aim for study	"The objective of this cluster randomised trial is to assess whether implementation of specific nutrition and PA components of the written school wellness policies lead to healthier student outcomes, including BMI trajectories and behavioral correlates"
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote from publication: "randomisation was achieved using a computer‐generated sequence"
Allocation concealment (selection bias)	Low risk	Quote from publication: "to minimize selection bias, all schools were recruited before randomisation"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote from publication: "neither schools nor researchers could be blinded to study condition"
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote from publication: "neither schools nor researchers could be blinded to study condition"
Incomplete outcome data (attrition bias) Anthropometrics, Fitness	Low risk	Comment: most missing data due to students moving
Selective reporting (reporting bias)	High risk	Comment: mental health and standardised test scores not reported
Cluster RCT ‐ Recruitment bias	Unclear risk	Quote from publication: "schools were recruited before randomisation" Comment: unclear when baseline data were collected
Cluster RCT ‐ Baseline imbalance	Low risk	Comment: there were no notable school‐level differences in size or relevant socioeconomic characteristics
Cluster RCT ‐ Loss of clusters	Low risk	Comment: no clusters lost
Cluster RCT ‐ Incorrect analysis	Low risk	Quote from publication: "multivariable analyses accounted for multilevel nature of data, adjusting for intra‐cluster correlation among repeated measures within students and schools, and allowed use of all study time points"