Fitzgibbon 2011.

Study characteristics
Methods	Study design: RCT Intervention period: 14 weeks Follow‐up period (post‐intervention): 12 months Differences in baseline characteristics: reported Reliable outcomes: reported Protection against contamination: NR Unit of allocation: school Unit of analysis: individual accounting for class and school
Participants	N (controls baseline) = 323 N (controls follow‐up) = 258 N (interventions baseline) = 346 N (interventions follow‐up) = 285 Setting (and number by study group): 18 preschools (N = 9 intervention schools and N = 9 control) Recruitment: targets 3‐5‐year‐old children enrolled in 18 Head Start programmes Geographic region: Chicago, USA Percentage of eligible population enrolled: 56% schools, 92% participants Mean age: intervention, 50.7 (SD: 6.8); control: 51.9 (SD: 6.3) ‐ months Sex: intervention, 52% female; control, 55% female
Interventions	The Hip‐hop to health Jr obesity prevention effectiveness trial is a 14‐week nutrition and PA intervention delivered by teachers that builds on results of Hip hop to health junior. Adapted curriculum so that teachers were asked to teach 2 weekly sessions, with the option of including a 3rd session if they chose. Each week focused on a particular theme with a specific objective. Each session included a 20‐min lesson related to healthy eating and exercise, as well as a 20‐ minute PA component. Lessons featured the colourful 'Pyramid Puppets' that represent the 7 food groups of the food pyramid. In addition, the intervention incorporated songs and raps that were included on a CD for teachers to play for their students. The CD also included 2 fully scripted exercise routines. Parents also received a weekly newsletter that paralleled the children’s curriculum in content and included a homework assignment. Parents received USD 5 for each of the homework assignments that they completed and returned. Each parent also received the same CD that the teacher used in the classroom so that the nutrition concepts and importance of PA could be reinforced in the home. Description of control: 14 weeks long and taught once a week. The children learned a variety of health concepts, including car seat and seat belt safety, immunisations, dental health, and the procedures for calling 911. Parents received a weekly newsletter that mirrored the weekly theme of the school‐based curriculum but were not asked to complete homework assignments. Diet and PA combination intervention vs control
Outcomes	Outcome measures Primary outcome: BMI and zBMI Secondary outcomes: dietary intake, PA, screen time Process evaluation: NR
Implementation‐related factors	Theoretical basis: SCT, Self‐Determination theory Resources for intervention implementation: reported Who delivered the intervention: reported PROGRESS categories assessed at baseline: gender, race/ethnicity; parent: gender, education, SES (income), occupation, social status (marital) PROGRESS categories analysed at outcome: NR Outcomes relating to harms/unintended effects: NR Intervention included strategies to address diversity or disadvantage: no, but study targeted at low‐income, black minority children. Also cultural modifications such as addressing environmental considerations (social support, unsafe neighbourhoods, economic restrictions, conflicting responsibilities) Economic evaluation: NR
Notes	Funding: the Hip‐hop to health obesity prevention effectiveness trial was supported by the National Heart, Lung and Blood Institute (HL081645) Teacher training: for intervention and control groups the initial training sessions were 3 h. Following the 1st formal session, the intervention co‐ordinator conducted 3 in‐school training sessions for the intervention teachers and 1 in‐school session for the control teachers. Resources for sessions: any paperwork/booklets (not described), puppets and CDs used in lessons, weekly newsletter for parents, CD for parents (same as used by teacher in classroom to convey nutrition concepts and importance of PA)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation, no further details
Allocation concealment (selection bias)	Unclear risk	NR
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Both parents and interviewers were aware of group assignments. No further details
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low attrition. 18% to 20% at 1 year for BMI at 14 weeks
Selective reporting (reporting bias)	Unclear risk	Protocol/trial registration document were unavailable
Other bias	Low risk	No other potential threats to validity
Other bias‐ timing of recruitment of clusters	Low risk	Figure shows recruitment happened before randomisation