Puder 2011.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 11 months Unit of allocation: preschool class Unit of analysis: child
Participants	Service type: centre‐based (preschools) Operation: public Country (region): Switzerland (St Gallen and Lausanne) Country income classification: high Low‐SES sample: yes Population description: public preschool classes in areas with a high migrant population from 2 different sociocultural and linguistic regions in Switzerland. The study was conducted in the German‐speaking (city of St Gallen; 70,000 inhabitants) and the French‐speaking (urban surroundings of Lausanne, canton Vaud; 50,000 inhabitants) regions of Switzerland during the school year 2008‐9. All children in Switzerland attend preschool. The city of St. Gallen and the Lausanne area were chosen due to a high prevalence (i.e. at least 40%) of children of migrant background. Migrant background was defined as at least one parent born out of Switzerland. Inclusion criteria: inclusion criteria were > 40% prevalence of migrant children and no participation in any other prevention project. Exclusion criteria: not reported Number of services randomised: 40 (20 intervention, 20 control) Number of children randomised: 727 (342 intervention, 310 control) Characteristics Children Age: 5.2 years (SD 0.6) Gender (% female): 50% Ethnicity: Mainly speak a foreign language at home (any language other than German or French): 40% Most common migrant regions (according to country of birth of father): Former Yugoslavia: 25% (91); Portugal: 17%; rest of Europe: 31%; Africa: 12%; rest of world: 15% Parents Age (years): not reported Gender (% female): not reported Ethnicity: 1 parent migrant: 24%; both parents migrant: 48% Migrant areas: Yugoslavia: 25%; Portugal: 17%; rest of Europe: 31%; Africa: 12%; rest of world: 15% Parent/family SES: Parental low education level (max 9 years education): neither parent: 62%; 1 parent: 21%; both parents 17% Method of recruitment: not reported Missing data/dropout: all ECEC classes retained. Of the 655 children with consent, 652 were present at baseline for BMI measures Reasons for dropout: 26 children dropped out of the intervention due to moving away. Characteristics of dropouts: not reported
Interventions	Programme name: Ballabeina Number of conditions: 1 intervention, 1 control Intervention duration: 1 school year Intervention setting: ECEC and home Intervention strategies: Health curriculum Children Education: 22 sessions on healthy nutrition, media use, and sleep Ethos and environment Children Exposure: 45‐min physical activity sessions prepared by an exercise physiologist with the aim to improve aerobic fitness and co‐ordination skills. Taught weekly by a health promoter for the first 4 months and then reduced to twice a month and taught by preschool teachers. Children in preschool classes are exclusively offered water and healthy food. Resources: every other week children received a new fun physical activity or nutrition activity card to take home and a CD with music. ECEC staff Workshops: teachers participated in 2 x workshops before the intervention to learn about the content and the practical aspects of the intervention. Meeting: 1 formal meeting to exchange their experience and involved in evenings organised for the parents. Support: teachers were supported to deliver physical activity sessions through hands‐on training by health promotors during the initial visits. Health promoters also assisted in the choices regarding how to adapt the built environment in and around the preschool class. Service Environment: healthy snacks during recess and healthy treats for special occasions were promoted and water and healthy food was exclusively offered during class. Fixed and mobile equipment were installed or provided in and around classrooms, including a “movement corner.” Materials: coloured poster of the "Ballabeina track", was hung in classroom and stickers were pasted on the poster to show progress. Event: a Ballabeina event was organised with games implementing the main messages of the intervention. All participants Cultural: intervention culturally tailored based on evaluation of norms and needs. Partnerships Families Meetings: 3 x interactive information and discussion evenings. Organised by health promoters in collaboration with preschool teachers Resources: brochures, information leaflets, physical activity or nutrition activity cards and worksheets. The information leaflets for parents were provided in 10 different languages, and native speakers of the main foreign languages were available to answer questions. Healthcare Delivery: health promoters assisted in the delivery of the intervention. Intensity of intervention: 4 x 45‐min sessions of physical activity each week (trained staff delivered these once a week, which was reduced to twice a month after 4 months) for children; 22 sessions on healthy nutrition/media use and sleep for children; take home messages once/week for children; 1 x Ballabeina event (organised games, and materials provided); 2 x teacher workshops; 3 x interactive parent information evenings Intervention delivered by: research team, ECEC staff, healthcare staff Modality: face‐to‐face, written Theoretical basis: Social Ecological Model Description of control: usual care
Outcomes	Outcomes relating to child dietary intake: Proportion healthy eaters Number of participants analysed: Intervention baseline: 342 Intervention follow‐up: 333 Control baseline: 310 Control follow‐up: 292 Data collection measure: semi‐qualitative FFQ Data collector: parent Validity of measures used: not reported Outcomes relating to child physical measures: BMI, percentage body fat, sum of 4 skin folds, waist circumference, overweight or obese Number of participants analysed: Intervention baseline: 342 Intervention follow‐up: 333 Control baseline: 310 Control follow‐up: 292 Data collection measure: objective measure (IOTF) Data collector: researcher Validity of measures used: not reported Outcome relating to child language and cognitive performance: Attention, spatial working memory Number of participants analysed: Intervention baseline: 342 Intervention follow‐up: 333 Control baseline: 310 Control follow‐up: 292 Data collection measure: Konzentrations‐Handlungsverfahren für Vorschulkinder and Intelligence and Development Scales Data collector: parent Validity of measures used: validated Outcome relating to child social/emotional measures: not reported Outcome relating to child quality of life: Quality of life Number of participants analysed: Intervention baseline: 342 Intervention follow‐up: 333 Control baseline: 310 Control follow‐up: 292 Data collection measure: general health questionnaire (PedsQL 4.0) Data collector: parent Validity of measures used: validated Outcome relating to cost: not reported Outcome relating to adverse consequences: Study authors state only, "No injuries or other adverse events occurred during physical activity sessions in the intervention classes" Number of participants analysed: not reported Data collection measure: not reported Data collector: not reported Validity of measures used: not reported
Notes	Funding source: mainly supported by the Swiss National Science Foundation (grant No 3200B0‐116837) and Health Promotion Switzerland (project No 2104). Additional funding was obtained from a research award for interdisciplinary research from the University of Lausanne, a Takeda research award, the Wyeth Foundation for the Health of Children and Adolescents, the Freie Akademische Gesellschaft, and an unrestricted educational grant from Nestlé.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Classes were randomised (1:1) with the use of opaque envelopes.
Allocation concealment (selection bias)	Low risk	Allocation took place after all classes were recruited and selected by someone from the school health services who was not involved in the study.
Blinding of participants and personnel (performance bias) Diet outcomes	Unclear risk	Teachers, parents, and children were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. Specially trained researchers measured outcomes and were blinded to group allocation. Eating habits were assessed by the parents with a semi‐qualitative FFQ.
Blinding of participants and personnel (performance bias) Physical outcomes	Low risk	Teachers, parents, and children were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. However, the outcome is not likely to be influenced by lack of blinding.
Blinding of participants and personnel (performance bias) Language and cognitive performance outcomes	Low risk	Teachers, parents, and children were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. Specially trained researchers measured outcomes and were blinded to group allocation. The outcome is not likely to be influenced by lack of blinding
Blinding of participants and personnel (performance bias) Quality of life outcomes	Unclear risk	Teachers, parents, and children were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. Specially trained researchers measured outcomes and were blinded to group allocation. It is unclear whether the outcome could be influenced by lack of blinding.
Blinding of participants and personnel (performance bias) Adverse consequences	Unclear risk	Teachers, parents, and children were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. It is unclear whether the outcome could be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) Diet outcomes	Unclear risk	Eating habits were assessed by the parents with a semi‐qualitative FFQ. Parents were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. It is unclear if blinding could have been broken.
Blinding of outcome assessment (detection bias) Physical outcomes	Low risk	Specially trained researchers measured children's height, weight, bioelectrical impedance analysis, skinfold thickness, and waist circumference and were blinded to group allocation.
Blinding of outcome assessment (detection bias) Language and cognitive performance outcomes	Low risk	Attention and spatial working memory were assessed by specially trained researchers who were blinded to group allocation.
Blinding of outcome assessment (detection bias) Quality of life outcomes	Unclear risk	Parents completed the health‐related quality of life questionnaire. Parents were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. It is unclear if blinding could have been broken.
Blinding of outcome assessment (detection bias) Adverse consequences	Unclear risk	Teachers, parents, and children were informed that the intervention aimed to promote children’s health but were unaware of the main objectives of the study. It is unclear whether the outcome could be influenced by lack of blinding.
Incomplete outcome data (attrition bias) Diet outcomes	Low risk	Data were available for 333 (97%) children in the intervention group and 292 (94%) children in the control group. Amount of loss and reasons for loss to follow‐up similar between groups (i.e. child moved away after baseline testing). Therefore, risk of attrition bias was considered to be low.
Incomplete outcome data (attrition bias) Physical outcomes	Low risk	Data were available for 333 (97%) children in the intervention group and 292 (94%) children in the control group. Amount of loss and reasons for loss to follow‐up similar between groups (i.e. child moved away after baseline testing). Therefore, risk of attrition bias was considered to be low.
Incomplete outcome data (attrition bias) Language and cognitive performance outcomes	Low risk	Data were available for 333 (97%) children in the intervention group and 292 (94%) children in the control group. Amount of loss and reasons for loss to follow‐up similar between groups (i.e. child moved away after baseline testing). Therefore, risk of attrition bias was considered to be low.
Incomplete outcome data (attrition bias) Quality of life outcomes	Low risk	Data were available for 333 (97%) children in the intervention group and 292 (94%) children in the control group. Amount of loss and reasons for loss to follow‐up similar between groups (i.e. child moved away after baseline testing). Therefore, risk of attrition bias was considered to be low.
Incomplete outcome data (attrition bias) Adverse consequences	Unclear risk	The number of services and participants that reported on this outcome at follow‐up is unclear.
Selective reporting (reporting bias)	Low risk	The study protocol and trial registration are available and all of the study's pre‐specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre‐specified way.
Recruitment bias	Low risk	Individuals and classes were recruited before randomisation.
Baseline imbalance	Low risk	There were no differences in baseline characteristics and outcome variables between the intervention and control groups (all P ≥ 0.2).
Loss of clusters	Low risk	No loss of clusters
Incorrect analysis	Low risk	Study authors stated that "Analyses were performed on an intention to treat basis, by using data from individual children but adjusting for clustering of outcomes within preschool classes."
Contamination	Unclear risk	No evidence to make assessment
Other bias	Unclear risk	Grant money was received from a commercial organisation.