Kristiansen 2019.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 1 year (varies with outcomes) Unit of allocation: kindergartens Unit of analysis: child
Participants	Service type: centre‐based (kindergarten) Operation: public (control 42.5% vs intervention 57.5%) or private (control 57.5% vs intervention 42.5%) Country (region): Norway (Vestfold and Buskerud) Country income classification: high Low‐SES sample: unclear Population description: not reported Inclusion criteria: the target group for the current study was preschool children with year of birth 2010 and 2011, attending public or private kindergartens in the counties of Vestfold and Buskerud, Norway. Exclusion criteria: not reported Number of services randomised: 73 (37 intervention, 36 control) Number of children randomised: 633 (313 intervention, 320 control) Characteristics Children Age: 3‐5 year‐olds Gender (% female): Intervention: 51.1% Control: 51.9% Ethnicity: not reported Parents Age (years): not reported Gender (% female): not reported Ethnicity: not reported Parent/family SES: Maternal education: Intervention: low (≤ upper secondary: 32.9%; high (college/university): 67.1% Control: low: 29.9%; high (college/university): 70.1% Method of recruitment: all regular kindergartens (n = 479) in the 2 counties were invited by letter followed‐up by a phone call to inform about the study and to motivate for participation Missing data/dropout: from baseline to follow‐up 1, 16 children (5%) were lost to follow‐up in the control group and 20 children (6%) were lost to follow‐up in the intervention group. Reasons for dropout: the main reason for this loss was children moving to other kindergartens. Characteristics of dropouts: dropout analysis showed no differences in background characteristics between participating children (n = 633) and those lost to follow‐up (n = 66), except that significantly more children were lost in the intervention group compared to the control group (P = 0.02)
Interventions	Programme name: BRA‐study (an acronym for the Norwegian words “Barnehage” (kindergarten), “gRønnsaker” (vegetables) and “fAmilie” (family)) Number of conditions: 1 intervention, 1 control Intervention duration: 5 months Intervention setting: ECEC and home Intervention strategies: Ethos and environment ECEC staff Training: kindergarten staff received a 1‐d inspirational course (cooking, taste testing, theoretical sessions, action plans). Attendees were instructed to train/inform the relevant staff in their kindergarten. The theoretical sessions covered availability, accessibility, encouragement and role modelling. Service Resources: each kindergarten received 4 aprons, a vegetable memory game, booklets, 1 hand blender, 6 posters and brochures. They were also given access to a website with all materials and additional information about vegetables and 4 determinants and invited to a closed Facebook group. Booster: booster activities were provided at 3 months and 6 months and included booklets with recipes; a vegetable card/poster to register when and which vegetables were served for 3 d with potential for winning a gift card; and suggestions of tasting games to play with the children. Partnerships Families Resources: kindergarten staff provided families with a 'welcome package' including a cover letter explaining the rationale and the purpose of the intervention, a brochure with vegetable recipe ideas, a stack of post‐its with prompts to buy fruit and vegetables and a booklet to read to children. They were also given access to a website with all materials and additional information about vegetables and 4 determinants and invited to a closed Facebook group. Booster: booster activities were provided at 3 months and 6 months and included booklets with recipes; a vegetable card/poster to register when and which vegetables were served for 3 d with potential for winning a gift card; and suggestions of tasting games to play with the children. Intensity of intervention: 1 x inspirational training day; 1 x resource pack to staff; 1 x resource pack to parents, 1 x website materials to parents and staff (each), 1 x Facebook page for parents and staff (each), 2 x staff booster training; 2 x parent booster training/activity Intervention delivered by: research team, ECEC staff Modality: face‐to‐face, online, written Theoretical basis: not reported Description of control: wait‐list control
Outcomes	Outcomes relating to child dietary intake: Vegetable intake, variety in vegetable intake Number of participants analysed: Intervention baseline: 129‐222 Intervention follow‐up: 137‐218 Control baseline: 142‐206 Control follow‐up: 160‐229 Data collection measure: parent questionnaire, direct observation and combination of parent questionnaire and direct observation Data collector: parents and researchers Validity of measures used: not reported Outcomes relating to child physical measures: 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: The Research Council of Norway (project number 228452) with supplementary funds from the Throne Holst Nutrition Research Foundation, University of Oslo
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	An external statistician conducted a stratified block randomisation. The randomisation ensured an equal distribution of kindergartens within ownership (public and private) in the 2 groups and total number of participating children in each group. However, the study authors state that the subsample of children who were observed for diet outcomes were "preferably, children of mothers with a low educational level...and otherwise children were chosen for observation at random." The random sequence generation procedure for this subsample was not described.
Allocation concealment (selection bias)	Low risk	Allocation was conducted after baseline data collection, however this was done by an independent statistician to ensure even groups.
Blinding of participants and personnel (performance bias) Diet outcomes	High risk	Kindergarten employees were not blind to study allocation as they received kitchen education. Families were not blind as they received take‐home packages and website log‐ons. The outcome is likely to be influenced by lack of blinding
Blinding of outcome assessment (detection bias) Diet outcomes	Unclear risk	Study authors state that "Researchers were not blinded to intervention group during data collection at follow‐up 1. However, as there occasionally were options for the researchers to observe the same child/children during the direct observation of vegetable intake, intraclass correlation (ICC) as an estimate of inter‐rater reliability between pairs of observers was calculated. The level of agreement between pairs of observers at follow‐up 1 was 0.99 for the 37 children that were observed by two researchers. This agreement did not change when split into intervention (n 24, ICC = 0.99) and control groups (n 13, ICC = 0.98). This corresponds to the ICC found in the baseline data collection. Hence, this might indicate an unbiased observed vegetable intake." Study authors also state "Parents reported children's dietary intake and knew the aims of the intervention." As dietary outcomes were assessed by 2 methods (observation and parent‐reported data), risk of bias is unclear.
Incomplete outcome data (attrition bias) Diet outcomes	High risk	Follow‐up data from observation are available for 311 (76%) of the 411 children who were observed at baseline. Follow‐up data from the questionnaire were available for 311 (71%) of the 439 children with baseline data, and follow‐up data from the 24‐h recall are available from 295 (63%) of the 470 children with baseline data. Reasons for missing data not provided. Due to the magnitude of missing data, the risk of bias was assessed as high.
Selective reporting (reporting bias)	Unclear risk	Trial registration states the following primary outcome measures: "Frequency and variation of vegetable intake in children is measured by internet‐based questionnaires completed by parents at baseline (Spring 2015), year 1 (Spring 2016), and year 2 (Spring 2017)," and "Amount of vegetables consumed by children is measured using an internet‐based 24 hour recall where parents report the amounts of vegetables that the child ate the day before at baseline (Spring 2015), year 1 (Spring 2016), and year 2 (Spring 2017)." However, the study combines the internet‐based 24‐h recall with the direct observation to determine baseline total vegetable amount rather than reporting the outcomes of the internet‐based 24‐h recall alone.
Recruitment bias	Low risk	Individual recruitment occurred before randomisation of clusters.
Baseline imbalance	Low risk	At baseline, groups differed by percent of children attending a public kindergarten, and in children's frequency and variety of vegetable intake. Statistical models adjusted for baseline intake and kindergarten ownership (private or public).
Loss of clusters	Unclear risk	No loss of cluster reported, however some kindergartens had 0‐22 students.
Incorrect analysis	Low risk	Study authors stated that "Kindergarten was used as a random effect to account for random inhomogeneity between kindergartens."
Contamination	Unclear risk	No evidence to make assessment
Other bias	Low risk	No clear other source of bias