Pearson 2022.

Study characteristics
Methods	Study design: cluster‐RCT Length of follow‐up from baseline: 4 months Unit of allocation: centre Unit of analysis: child
Participants	Service type: centre‐based Operation: Lunchbox services Country (region): Australia (Hunter New England) Country income classification: high Low‐SES sample: no Population description: the sample area includes major metropolitan centres and inner regional communities, with a small proportion (14%) of people in remote communities. Inclusion criteria: ECEC services from the region that required parents to provide food for consumption at the service (i.e. lunch box services). Recruitment for the trial occurred in 2 phases. Initially, ECEC services were eligible to participate in the trial if they enrolled children aged 3‐6 years and were existing users of the designated parent communication app. As this eligibility criterion did not result in adequate ECEC services being recruited, phase 2 recruitment extended the eligibility criteria to include ECEC services not yet using the app but willing to commence using the app for the trial. Parents or carers of children aged 3‐6 years were eligible to participate if their child attended during the designated days of data collection and if they used or indicated a willingness to download the intervention app on the consent form. Exclusion criteria: services were excluded if they were participating in any other trial related to improving child nutrition, catered exclusively for children with special needs or are a Department of Education community‐run service (as they are not covered within the ethics arrangement). Children were excluded if they had special dietary requirements or allergies that would necessitate specialised tailoring of their diet. Number of services randomised: 18 (9 intervention, 9 control) Number of children randomised: 400 children (191 intervention, 209 control) Characteristics Children Age: Intervention: 3.9 years (SD 0.68); control: 3.9 years (SD 0.67) Gender (% female): Intervention: 52.1% Control: 51.6% Ethnicity: not reported Parents Parent/caregiver age (years): not reported Parents gender (% female): not reported Parent/Caregiver Ethnicity: not reported Parent/family SES: Low SES: intervention: 62.8% Control: 55.7%; High SES: intervention: 37.2% Control: 44.3% Parent education: Attended or completed high school: Intervention: 23.4% Control: 22.2%; Technical or further education (TAFE) certificate or diploma: intervention: 31.6% Control: 32.8% Completed university or college degree or higher Intervention: 44.9% Control: 45% Method of recruitment: for both phases, recruitment involved research assistants posting and emailing information statements and consent forms to ECEC services outlining the study, data collection procedures, and requesting participation. To obtain parental consent for participation in the study, ECEC service staff distributed hard copies of parent information statements and consent forms. Parents could also consent on the day of the data collection. Missing data/dropout: a service in the intervention arm ceased using the required app and withdrew from the study (before baseline data but after random allocation). Consumption data were collected for 88% (352/400) of children at baseline and for 84.3% (337/400) after the intervention. Reasons for dropout: a service in the intervention arm ceased using the required app and withdrew from the study. Child attrition reasons were not reported. Characteristics of dropouts: not reported
Interventions	Programme name: SWAP IT for Childcare Number of conditions: 1 intervention, 1 control Intervention duration: 10 weeks Intervention setting: ECEC and home Intervention strategies Ethos and environment Service Endorsement: the service managers were asked to communicate their endorsement of the intervention and guidelines to educators via a staff meeting or individual briefings and provide hard copies of the SWAP IT messages and the SWAP IT Lunchbox guidelines. Support: a health promotion officer conducted a brief onsite visit with the service manager to familiarise them with the guidelines and provide support to integrate these with existing service lunchbox policies (if required). Monitoring: a record of implementation was given to service managers to enable them to record their delivery of the agreed tasks during the intervention period. Parents Communication: service managers were asked to send 2 communications to parents via the app or other preferred communication methods (e.g. hard copy newsletters). Partnerships Parents Resource: parents were given access to the Skoolbag app which encourages the use of service‐endorsed ‘SWAP IT Options’ lunchbox guidelines recommending which foods and drinks to ‘swap from’ and which to ‘swap to’ when packing a healthy lunchbox. The guidelines were developed by dietitians and provide specific guidance in line with the Australian Guide to Healthy Eating, recommendations outlined in the NSW Ministry of Health nutrition sector‐specific resource and health and well‐being requirements outlined in national accreditation standards. Parents were also able to access messages and images, and through attachments and links to the ‘SWAP IT Childcare’ webpages, videos, fact sheets and other websites. Communication: push notifications alerted parents to messages sent via the service’s app for 10 weeks (1/week). Intensity of intervention: Parents: 1 x push notification for 10 weeks, plus an additional notification in the first week. 2 x communication by service (via app, email or preferred communication methods) Service: 1 on‐site visit (if required), implementation record Intervention delivered by: ECEC staff, healthcare staff Modality: face‐to‐face, online, written Theoretical basis: Behaviour Change Wheel Description of control: usual care
Outcomes	Outcomes relating to child dietary intake: Vegetable intake, fruit intake, discretionary foods intake, breads and cereals intake, dairy intake, meat and alternatives intake, mean energy from discretionary foods, mean energy, saturated fat, total and added sugars, sodium consumed from all foods and calorific drinks packed in children’s lunch boxes Number of participants analysed Intervention baseline: 138 Intervention follow‐up: 137 Control baseline: 165 Control follow‐up: 164 Data collection method: weighed plate waste enhanced with digital photography and written records Data collector: researchers Validity of measures used: validated 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: owing to the null findings, a cost‐effectiveness analysis, as specified in the study protocol, was not conducted. Outcome relating to adverse consequences: Changes in the frequency of parent complaints or concerns regarding healthy lunch box policy Number of participants analysed: not reported Data collection method: service manager pen and paper survey Data collector: service manager Validity of measures used: not reported
Notes	Funding source: this research received no specific grant from any funding agency in the public, commercial or not‐for‐profit sectors. Infrastructure funding was provided in kind by Hunter New England Population Health.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Study authors stated that "ECEC services were randomly allocated to the intervention group or no intervention control group in a 1:1 ratio by a statistician independent of the trial using a computerized random number generator."
Allocation concealment (selection bias)	Low risk	Centres were allocated to groups following recruitment.
Blinding of participants and personnel (performance bias) Diet outcomes	Unclear risk	Study authors state "Owing to the nature of the intervention, ECEC services and parents were not blinded to the intervention; however, outcome assessors were blinded to the service allocation." It is unclear whether lack of blinding would affect the outcome. For example, teachers could have encouraged their students to eat more of certain foods from their lunches on the days of observation, though this is unknown.
Blinding of participants and personnel (performance bias) Adverse consequences	Unclear risk	Services were not blind to study allocation. It is unclear whether the outcome is likely to be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) Diet outcomes	Low risk	Study authors state "outcome assessors were blinded to the service allocation."
Blinding of outcome assessment (detection bias) Adverse consequences	Unclear risk	Services were not blind to study allocation. It is unclear whether the outcome is likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) Diet outcomes	Low risk	Study authors stated that "Consumption data were collected for 88% (352/400) of children at baseline and for 84.3% (337/400) after the intervention."
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)	High risk	Study authors stated that "Owing to the null findings, neither a cost‐effectiveness analysis, as specified in the study protocol, nor the planned analysis of data collected on the usual daily dietary intake of children (to be able to detect any compensatory dietary behaviors) was conducted."
Recruitment bias	Low risk	Allocation took place after recruitment and before baseline data collection.
Baseline imbalance	Low risk	Study authors stated that "Characteristics were similar across groups; however, the intervention group had a higher proportion of parents located in the outer regional areas than the control group. As the intervention was delivered at the cluster level rather than at the individual level, geographical remoteness was accounted for by stratifying services by this factor during randomisation and not controlled for as part of the analysis."
Loss of clusters	High risk	Study authors stated that "A service in the intervention arm ceased using the required app and withdrew from the study (before baseline data but after random allocation)."
Incorrect analysis	Low risk	Study authors stated that "Models were adjusted for potential ECEC service level clustering through a service random effect and controlled for baseline service Environment and Policy Assessment and Observation score and if ECEC services were existing app users before the trial."
Contamination	Low risk	Study authors stated that "No contamination was reported; that is, the app was not used to send any other health or nutrition information. No ECEC services in the intervention or control groups reported exposure to additional nutrition interventions throughout the duration of the trial."
Other bias	Low risk	No other clear source of bias