Fitzgibbon 2013.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 14 weeks Unit of allocation: preschool Unit of analysis: child
Participants	Service type: centre‐based (Head Start) Operation: public Country (region): USA (Chicago) Country income classification: high Low‐SES sample: yes Population description: Hispanic children and their parents Inclusion criteria: a parent‐child dyad was eligible if the parent gave informed consent for herself and the child, the child's height and weight were measured at baseline, and the child was still enrolled in a participating classroom when the intervention began. Up to 2 children per family were eligible to participate. Exclusion criteria: not reported Number of services randomised: 4 (2 interventions, 2 control) Number of children randomised: 157 (78 intervention, 79 control) Characteristics Children Age: 54.2 months (SD 5.0) Gender (% female): 50% Ethnicity: Latino: 94%; black: 2%; multiracial/other: 4% Parents Age (years): 32.8 (SD 6.0) Gender (% female): 89% Ethnicity: unclear Parent/family SES: Income (USD median: 15,000 Parent education (years): 11.2 (SD 2.2) Method of recruitment: not reported Missing data/dropout: all clusters retained, however 1 intervention and 2 control participants were missing from follow‐up. Reasons for dropout: not reported Characteristics of dropouts: not reported
Interventions	Programme name: Family‐Based Hip‐Hop to Health Number of conditions: 1 intervention, 1 control Intervention duration: 14 weeks Intervention setting: ECEC and home Intervention strategies: Health curriculum Children Education: a nutrition and physical activity curriculum (3 x/week) was provided to children, led by bilingual/bicultural educator and supplemented by a Spanish language CD. The nutrition instructions included activities led by puppets representing food groups. The nutrition and physical activity components designed to target specific child behaviours (e.g. increase consumption of fruits and vegetables, reduce television viewing, and increase duration of daily physical activity). Ethos and Environment Children Exposure: each session also included 20 min of aerobic activity. All participants Cultural: the intervention was tailored to cultural and developmental needs of the population (lower‐income, Hispanic populations). Partnerships Parents Education: parents encouraged to attend 6 weekly 90‐min classes that included 60 min of interactive curriculum (healthy eating and exercise for weight management), supplemented with the Spanish language CD. Exposure: the remaining 30 min involved moderate physical activity (e.g. salsa aerobics, walking group). Resources: parents received weekly newsletters with programme information. Each family received a copy of the Spanish language CD to reinforce the classroom material at home. Intensity of intervention: 40‐min nutrition education sessions/week for children; 6 x 90‐min education sessions for parents; weekly newsletters for parents Intervention delivered by: ECEC staff Modality: face‐to‐face, written Theoretical basis: Social Cognitive Theory, the Health Belief Model and Self‐Determination Theory Description of control: alternative intervention control (covered health concepts including seat belt safety, immunisation, dental health and calling 911)
Outcomes	Outcomes relating to child dietary intake: Energy, total fat, fibre, fruit, 100% fruit juice, vegetables Number of participants analysed: Intervention baseline: 55 Intervention follow‐up: 50 Control baseline: 58 Control follow‐up: 56 Data collection measure: 24‐h diet record (combination of in‐care observations and parent records for all foods consumed outside of care) Data collector: parent‐reported and researcher observations Validity of measures used: not reported Outcomes relating to child physical measures: BMI, BMI z‐score, weight Number of participants analysed: Intervention baseline: 72 Intervention follow‐up: 71 Control baseline: 74 Control follow‐up: 72 Data collection measure: objectively measured (CDC) Data collector: not reported Validity of measures used: not reported Outcome relating to child language and cognitive performance: not reported Outcome relating to child social/emotional measures: not reported Outcome relating to child quality of life: not reported Outcome relating to cost: not reported Outcome relating to adverse consequences: not reported
Notes	Funding source: National Cancer Institute (CA121423), R25CA057699, and the Consortium to Lower Obesity in Chicago Children (CLOCC)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The random sequence generation procedure was not described.
Allocation concealment (selection bias)	Unclear risk	No information on the method of allocation concealment reported
Blinding of participants and personnel (performance bias) Diet outcomes	High risk	We assumed that due to the nature of the intervention, ECEC service staff and study personnel delivering the intervention were not blind to the study allocation. The outcome is likely to be influenced by lack of blinding.
Blinding of participants and personnel (performance bias) Physical outcomes	Low risk	We assumed that due to the nature of the intervention, ECEC service staff and study personnel delivering the intervention were not blind to the study allocation. However, the outcome is not likely to be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) Diet outcomes	High risk	Dietary intake was reported by parents and observed by research staff. There was no blinding of outcome assessors, and the outcome measurement is likely to be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) Physical outcomes	Low risk	Children's height and weight were measured by interviewers aware of group assignments, however the outcome measurements are not likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) Diet outcomes	High risk	Only 76% of intervention and 78% of control had baseline diet data, and follow‐up loss was 9% of intervention children with baseline diet data (31% loss from all children in intervention group) and 3% of control children with baseline diet data (24% loss from all children in control group). Study authors stated that "Only participants with height and weight measurements, valid accelerometer records, complete screen time data, or valid diet data at baseline and follow‐up were included in the relevant follow‐up analyses." No information provided regarding reasons for missing data at follow‐up. Due to the magnitude of missing data, the risk of bias was assessed as high.
Incomplete outcome data (attrition bias) Physical outcomes	Low risk	Data were available for 71 (99%) participants in the intervention group and 72 (97%) students in the control group at post‐intervention. Study authors stated that "Only participants with height and weight measurements, valid accelerometer records, complete screen time data, or valid diet data at baseline and follow‐up were included in the relevant follow‐up analyses." Reason for missing data was similar across groups (i.e. missed visit). Therefore, risk of attrition bias was considered to be low.
Selective reporting (reporting bias)	Unclear risk	No prospective trial protocol or trial registration so it was unclear whether there was selective outcome reporting
Recruitment bias	Unclear risk	Per the PRISMA diagram, individual recruitment occurred after randomisation of preschools. However, it is unclear if parents were aware of allocation at recruitment.
Baseline imbalance	Unclear risk	Baseline analysis was conducted but results were not provided.
Loss of clusters	Low risk	No loss of clusters
Incorrect analysis	Low risk	Study authors stated that "We used a mixed model analysis of covariance to test for differences between groups in physical activity at post‐intervention and in screen time and diet at post‐intervention and follow‐up, controlling for school, classroom nested within school, and the baseline value." and "To test for differences between groups in BMI and BMI z‐score change at post‐intervention and 1‐year follow‐up, we used a mixed model ANOVA, controlling for school and classroom nested within school, as well as a mixed model analysis of covariance, controlling for school, classroom nested within school, the BMI percentile at baseline (< 85th or > 85th), baseline age, and time between visits."
Contamination	Unclear risk	No evidence to make assessment
Other bias	Low risk	No clear other source of bias