Fildes 2014

Methods	Study design: Randomised controlled trial Funding: "The recruitment of the Gemini cohort was funded by a grant from Cancer Research UK (no. C1418/A7974), and the design and production of the packs used in this study was funded by Weight Concern (registered charity no. 1059686)."
Participants	Description: Families with 3‐ to 4‐year‐old children from a larger cohort study (the Gemini study) N (Randomised): 1006 families Age: Child (mean): Intervention = 3.9 years, Control = 3.8 years Parent (mean): Intervention = 38.0 years, Control = 37.3 years % Female: Child: Intervention = 49%, Control = 50% Parent: not specified SES and ethnicity: Maternal education (below university level): intervention 49%, control = 49% Inclusion/exclusion criteria: Not specified Recruitment: “Participants were families with 3‐ to 4‐year‐old children from the Gemini study, a cohort of 2,402 families with twins born during 2007 in England and Wales. Currently active families (n=2,321) were sent information about a study to test a method of increasing children’s acceptance of vegetables” Recruitment rate: Families: 43% (1006/2321) Region: England and Wales
Interventions	Number of experimental conditions: 2 Number of participants (analysed): Intervention = 98, Control = 123 Description of intervention: “The intervention pack contained an exposure instruction leaflet, progress charts, and stickers. The exposure instructions asked parents to offer the child a single very small piece of their target vegetable every day for 14 days, allowing the child to choose a sticker as a reward if they tried it. They were asked to do this separately with each child and outside mealtimes.” Duration: 14 days Number of contacts: 14 Setting: Home Modality: Face‐to‐face Interventionist: Parents Integrity: “Among the 175 returned (89%), the mean number of exposure sessions was 13.8 (range=11 to 14), and children tasted their target vegetables a mean of 12.4 times (range=0 to 14). Children complied with the intervention by trying their target vegetable on an average of 90% (range 0% to 100%) of the exposure days during the experiment phase.” Date of study: Unknown Description of control: Received no intervention, “Control families were sent the intervention materials on completion of the study.”
Outcomes	Outcome relating to children's fruit and vegetable consumption: Child’s intake of the target vegetable (number of pieces). Parents “recorded the number of pieces (including half‐pieces) of vegetable the child ate; this comprised the intake measure.” Outcome relating to absolute costs/cost effectiveness of interventions: Not reported Outcome relating to reported adverse events: Not reported Length of follow‐up from baseline: 14 days Length of follow‐up post‐intervention: Immediately Subgroup analyses: None Loss to follow‐up: Intervention = 68% Control = 68% Analysis: Unknown if sample size calculation was performed
Notes	Mean and SEM were estimated from a study figure using an online resource (Plot Digitizer: plotdigitizer.sourceforge.net) for intervention and control groups at the end of the experimental phase (T3). Sensitivity analysis ‐ primary outcome: Fruit or vegetable intake is listed as primary outcome
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly allocated to experimental group but the random sequence generation procedure is not described
Allocation concealment (selection bias)	Unclear risk	There is no information provided about allocation concealment and therefore it is unclear if allocation was concealed
Blinding of participants and personnel (performance bias) All outcomes	High risk	Vegetable intake: There is no mention that the parents were blinded and they were cutting and offering the pieces to the child and this could have influenced performance
Blinding of outcome assessment (detection bias) All outcomes	High risk	Vegetable intake: There is no mention that the parents were blinded and they were cutting and offering the pieces to the child and so at high risk of detection bias
Incomplete outcome data (attrition bias) All outcomes	High risk	472 (47%) out of the 1006 randomised returned the outcome data sheets and therefore high risk of attrition bias
Selective reporting (reporting bias)	Unclear risk	There are secondary outcomes reported in the trial registration that are not presented in the outcomes paper
Other bias	High risk	Children in the intervention group had significantly lower intake and liking than the control group at baseline (i.e. baseline imbalances)