Robbins 2018.

Study characteristics
Methods	Study design: cluster‐RCT
Participants	School inclusion criteria: located in urban community setting; enrolment greater than 100 girls in each school or more than double the number of girls needed for the study site (N = 50/school) in any combination of Grades 5, 6, 7, and/or 8; student body comprising at least 50% minority versus non‐minority race or ethnicity and including a similar percentage enrolled in the free and reduced lunch programme School exclusion criteria: administrators not interested in participating, did not agree to random assignment, could not guarantee their availability at post‐intervention follow‐up Student inclusion criteria: girls in Grades 5 through 7 (ages 10 to 14; 8th graders if needed in schools having only Grades 7 and 8); available and willing to participate in the PA club 3 days/week for 17 weeks; available for follow‐up (9 months after intervention ends); agree to school random assignment; able to read, understand, and speak English Student exclusion criteria: involved in or planning to be involved in school or community sports or other organised PAs, such as dance lessons, that involve MVPA and require participation 3 or more days/week after school; a health condition precluding safe MVPA Setting: school, urban Age group: children/adolescents Gender distribution: females  Country where trial was performed: USA
Interventions	Intervention  An after‐school PA club 3 days/week at each school conducted by a club manager (1 of whom was male) and 3 to 4 female instructors, all of whom had recent experience conducting school‐ or community‐based PA programmes that involved girls whose ages were similar to those in this study Two face‐to‐face 15‐ to 20‐minute motivational, individually tailored counselling sessions (1 at the beginning, the other at the end of the intervention) with a female health professional having experience with adolescents (e.g. registered or school nurse) Interactive Internet‐based session via iPad (midpoint of intervention) set up by researchers at each school Comparator: students did not receive any after‐school programming other than the programming currently offered by the school and community Duration of intervention: 17 weeks Duration of follow‐up: 13 months Number of schools: 8 Theoretical framework: health promotion model and self‐determination theory
Outcomes	PA duration Fitness BMI
Study registration	NCT01503333 (retrospectively registered)
Publication details	Language of publication: English Funding: non‐commercial funding (governmental organisation) Publication status: peer‐reviewed journal
Stated aim for study	"The primary aim was to evaluate the effect of a Girls on the Move school‐based intervention on minutes of MVPA among fifth‐ to eighth‐grade girls"
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: a statistician used a computer programme to randomly assign the 2 schools in each pair to receive either intervention or control [author communication]
Allocation concealment (selection bias)	Low risk	Comment: schools were registered, paired, and randomised by an independent statistician [author communication]
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote from publication: "girls, parents or guardians, principals, nurses, and school staff are not told about hypotheses"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote from publication: "the measurement and intervention teams function independently so as to blind members of the former group to each school’s randomisation status throughout the entire study"
Incomplete outcome data (attrition bias) Anthropometrics, Fitness	Low risk	Quote from publication: "we determined data to be missing at random, and multiple imputation was employed. Based on recommendations and the complexity of the process, 20 imputations were conducted at the individual level"
Incomplete outcome data (attrition bias) Physical activity and sedentary time	Low risk	Quote from publication: "we determined data to be missing at random, and multiple imputation was employed. Based on recommendations and the complexity of the process, 20 imputations were conducted at the individual level"
Selective reporting (reporting bias)	Low risk	Comment: outcomes listed in protocol appear to have been reported on
Cluster RCT ‐ Recruitment bias	High risk	Quote from publication: "prior to the start of the school year, the PI and project manager inform each principal regarding the randomisation status of his or her respective school to assist each principal with future planning. Principals are told that the randomisation information must remain confidential until completion of baseline data collection in the fall"
Cluster RCT ‐ Baseline imbalance	Low risk	Quote from publication: "both groups of girls (N = 1519) were similar for most baseline characteristics. However, the control group had a higher proportion of Black girls (P = .001) and higher BMI (P = .035) than the intervention group. The intervention group had a higher proportion of healthy weight girls, but a lower proportion of obese girls than the control group (P = .046)"
Cluster RCT ‐ Loss of clusters	Low risk	Comment: no clusters lost [author communication]
Cluster RCT ‐ Incorrect analysis	Low risk	Quote from publication: "models included the group variable, cluster random effect of school, and the following fixed effects: age, BMI z‐score, race, socioeconomic status, ethnicity, pubertal stage, and study year"