Alkon 2014.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 7 months Unit of allocation: centre Unit of analysis: child
Participants	Service type: centre‐based Operation: not reported Country (region): USA (California, Connecticut, North Carolina) Country income classification: high Low‐SES sample: yes Population description: racial/ethnic diversity among the children Inclusion criteria: included English‐speaking director, on‐site kitchen, racial/ethnic diversity among the children, participation by at least 60% of families and a population of children in care primarily comprised of low‐income children between the ages of 3‐5 years Exclusion criteria: chronic illnesses or conditions that affected nutritional status, severe food allergies, gastrointestinal disorders or mobility impairment Number of services randomised: 18 (9 intervention, 9 control) Number of children randomised: 552 (260 intervention, 292 control) Characteristics Children Age: Intervention: 3 years: 31%; 4 years: 50%; 5 years: 19% Control: 3 years: 29%; 4 years; 54%; 5 years: 17% Gender (% female): Intervention: 44% Control: 48% Ethnicity: not reported Parents Age (years): not reported Gender (% female): not reported Ethnicity: Intervention: white: 55%; African American: 17%; Hispanic, Latino: 15%; Asian: 8%; other: 5% Control: white: 37%; African American: 16%; Hispanic, Latino: 19%; Asian: 19%; other: 9% Parent/family SES: Employment status (primary caregiver): Intervention: working full time: 74%; working part time: 14%; unemployed: 2%; student: 5%; not working: 5% Control: working full time: 74%; working part time: 17%; unemployed: 5%; student: 2%; not working: 2% Parent education (primary caregiver): Intervention: < high school: 23%; high school and higher: 77% Control: < high school: 44%; high school and higher: 56% Method of recruitment: not reported Missing data/dropout: 1 control centre withdrew and was replaced with a matched centre prior to intervention Reasons for dropout: the centre was unable to complete the required number of study questionnaires. Characteristics of dropouts: not reported
Interventions	Programme name: NAP SACC (The Nutrition And Physical Activity Self‐Assessment for Child Care) Number of conditions: 1 intervention, 1 control Intervention duration: 7 months Intervention setting: ECEC Intervention strategies: Ethos and environment ECEC staff Workshops: NAP SACC workshops for ECEC providers and staff included education on childhood obesity, healthy eating for young children, physical activity for young children, personal health and wellness and working with families to promote healthy behaviours. Support: on‐site consultations and additional telephone and email consultations Resources: written materials around nutrition and physical activity were provided to staff. Service Materials: posters displayed in centres and information sheets on nutrition and physical activity Policy: child‐care health consultants worked with centre directors to write and update the centre's nutrition and physical activity policies. Partnerships Families Workshop: services were provided the parent workshop 'raising healthy kids'. Resources: written materials around nutrition and physical activity were provided to parents. Healthcare Delivery: nurse child healthcare consultants delivered the intervention to staff and parents. Intensity of intervention: 5 x 1‐h NAPSACC workshops to ECEC providers and staff (e.g. cooks, administration); 1 x at least monthly consultations; additional phone and email consultations and posters and information sheets distributed (and displayed in the centre and provided to parents) Intervention delivered by: healthcare staff Modality: face‐to‐face, telephone, online, written Theoretical basis: not reported Description of control: delayed intervention control
Outcomes	Outcomes relating to child dietary intake: not reported Outcomes relating to child physical measures: BMI z‐score, % underweight, % healthy weight, % overweight, % obese Number of participants analysed: Intervention baseline: 99 Intervention follow‐up: 99 Control baseline: 110 Control follow‐up: 110 Data collection measure: objectively measured (CDC) Data collector: researcher 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: grant funded by the US Department of Health and Human Services, health resources and services administration, maternal and child health research program
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) 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) Physical outcomes	Low risk	Children's height and weight were measured by a research assistant blinded to group assignment.
Incomplete outcome data (attrition bias) Physical outcomes	High risk	One cluster withdrew prior to the intervention but after randomisation and was replaced. Study authors stated that "There were 211 children (63% of 336) with measurements at both the pre‐ and post‐intervention periods." Due to the magnitude of missing data, we assessed the risk of bias as high.
Selective reporting (reporting bias)	Unclear risk	No prospective trial protocol, and trial registration is vague so it was unclear whether there was selective outcome reporting
Recruitment bias	Unclear risk	It is unclear whether allocation occurred before or after baseline data collection. One control cluster was lost and replaced with a matched centre prior to intervention but after randomisation.
Baseline imbalance	Unclear risk	Although centres were matched on size and proportion of children eligible for income subsidies, groups significantly differed in parent ethnicity, parent education, employment status, and household density. Only state, parent education, and family poverty were included in regression analysis. Some known confounders of children's BMI, such as parent BMI and child‐level accelerometer and sleep data, were not collected.
Loss of clusters	Low risk	One control cluster lost and replaced with a matched centre prior to intervention
Incorrect analysis	Low risk	Hierarchical linear models were conducted to assess child‐level BMI z‐score outcomes while accounting for clustering within centres.
Contamination	Unclear risk	No evidence to make assessment
Other bias	Unclear risk	Study authors stated that "Third, some centres had more child‐level data and some states had more centres contributing to the final analyses. Fourth, some known confounders of children's BMI, such as parent BMI and child‐level accelerometer and sleep data were not collected... Lastly, there was a historical cohort effect on both the intervention and control centres given obesity prevention campaigns at the national level (i.e., Let's Move Child Care) and legislation (i.e., Healthy Hunger‐Free Kids Act) in the U.S. that promoted healthy nutrition and physical activity in child care during the study period." There is insufficient information to assess whether an important risk of bias exists.