Baskale 2011.

Study characteristics
Methods	Study design C‐RCT Funding “No external or intramural funding was received.”
Participants	Description Children 5 years of age in 12 nursery schools connected to the Izmir Provincial Directorate of National Education N (randomised) 6 preschools, 238 children Age Child: 5 years of age Parent (mean): intervention mothers = 33.4 years, control mothers = 33.4 years, intervention fathers = 36.9 years, control fathers = 36.8 years % female Child: intervention = 60%, control = 48% Parent: not reported SES and ethnicity Family SES: low = 16%, medium = 73%, upper = 11% Parent: education levels reported. Mother: primary = 9%, secondary school = 15%, high school = 38%, university = 38%. Father: primary = 10%, secondary school = 14%, high school = 37%, university = 40% Inclusion/exclusion criteria Not reported Recruitment Not reported Recruitment rate Child: not reported Nursery: not reported Region Izmir (Turkey)
Interventions	Number of experimental conditions 2 Number of participants (analysed) Intervention = 141, control = 97 Description of intervention “The content of the education guided by Piaget’s theory included play and visual materials. Thus, healthy food choices were created by means of play/games. Following age‐appropriate education carried out using Piaget’s theory, improvements are observed in food selection and consumption” Duration Initial intervention = 6 weeks and at 1 year follow‐up a 3 week refresher intervention (20 to 30 minutes per session) Number of contacts 9 sessions (1 per week) Setting Preschool Modality Face‐to‐face Interventionist “The researcher (H.B.), who is a nurse educator, was the interventionist for all sessions.” Integrity No information provided Date of study February 2007 to June 2008 Description of control “The children in the control group had not received nutrition education but they had received a general program of education (the nutrition education prescribed by the Ministry of National Education preschool). The yearly syllabus of the Ministry includes subjects on nutrition every 2 months. This time frame, however, may be insufficient for nutrition education.”
Outcomes	Outcome relating to children's fruit and vegetable consumption Child’s consumption of fruits and vegetables assessed using food frequency questionnaire (FFQ) completed by parents 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 Post‐test: 4 months (pre‐test February 2007 – post‐test June 2007) Post‐test 2: 16 months (post‐test 2 June 2008) Length of follow‐up postintervention Post‐test: 2 months Post‐test 2: 14 months Subgroup analyses None Loss to follow‐up (at 2 and 14 months) Intervention: 1%, 52% Control: 9%, 51% Analysis Did not adjust for clustering Sample size calculation was performed.
Notes	Sensitivity analysis ‐ primary outcome: Primary outcome not stated, power calculation conducted on knowledge only
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	Nutrition knowledge & food frequency (self‐reported) There is no blinding to group allocation of participants or personnel described and this is likely to influence performance
Blinding of outcome assessment (detection bias) All outcomes	High risk	Nutrition knowledge & food frequency There is no mention that participants were blinded to group allocation and therefore the risk of detection bias is high
Incomplete outcome data (attrition bias) All outcomes	High risk	67/141 (48%) in experimental group and 48/97 (49%) in control group completed post‐test 2 and therefore risk of attrition bias is high
Selective reporting (reporting bias)	Unclear risk	There is no study protocol therefore it is unclear if there was selective outcome reporting
Other bias	Low risk	Contamination, baseline imbalance, & other bias that could threaten the internal validity do not appear to be an issue