Campbell 2013.

Study characteristics
Methods	Study name: Melbourne infant, feeding, activity and nutrition trial (InFANT) program Study design: cluster‐RCT Intervention period: 15 months Follow‐up period (post‐intervention): nil Differences in baseline characteristics: reported Reliable outcomes: reported Protection against contamination: NR Unit of allocation: first‐time parents’ groups Unit of analysis: individual accounting for clustering
Participants	N (controls baseline) = 271 N (controls follow‐up) = 239 N (interventions baseline) = 271 N (interventions follow‐up) = 241 Setting (and number by study group): 62 parent‐group clusters from 28 eligible local government areas (intervention N = 31 parents’ groups and 271 children; control N = 31 parents’ groups and 271 children) Recruitment: 14 LGAs were randomly selected from the 28 eligible LGAs located within a 60‐km radius of the research centre. 50% of eligible first‐time parents’ groups (rounded to next even number) within each LGA were randomly selected (62/103 groups) and approached by research staff for recruitment during 1 of the standard nurse‐facilitated group sessions. Geographic region: Melbourne, Australia Percentage of eligible population enrolled: 86% Mean age: intervention: 3.9 ± 1.6 (months); control: 3.9 ± 1.6 (months) Sex: intervention: 48.3% female; control: 46.5% female
Interventions	To assess the effectiveness of a parent‐focused intervention on infants’ obesity‐risk behaviours and BMI Parents were offered six 2‐h dietitian‐delivered quarterly sessions over 15 months focusing on parental knowledge, skills, and social support around infant feeding, diet, PA, and TV viewing. Control group parents received 6 newsletters on non obesity‐focused themes; all parents received usual care from child health nurses. Diet and PA combined intervention vs control
Outcomes	Outcome measures Primary outcome: dietary intake, PA, TV viewing Secondary outcomes: zBMI Process evaluation: reported (perceived group session usefulness and relevance; fidelity)
Implementation‐related factors	Theoretical basis: SCT Resources for intervention implementation: reported Who delivered the intervention: reported PROGRESS categories assessed at baseline: child: gender; maternal education PROGRESS categories analysed at outcome: maternal education (secondary reference for Campbell 2013 examines moderating effect of zBMI by maternal education) Outcomes relating to harms/unintended effects: NR Intervention included strategies to address diversity or disadvantage: NR Economic evaluation: reported (costs of resources)
Notes	ISRCTN81847050 Funding: supported by the National Health and Medical Research Council (grant 425801). Additional funds were supplied by the Heart Foundation Victoria and Deakin University. Very young children of first‐time mothers The total estimated cost of delivering the programme, based on the costs of the intervention adjusted for the fact that a trial setting sees an artificially small number of families included relative to the workforce employed, was approximately AUD 500 per family.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation (stratified by LGA) was conducted by an independent statistician; balanced (1:1) randomisation; randomly ordered list of LGAs
Allocation concealment (selection bias)	Low risk	Randomisation of first‐time parents’ groups (clusters) occurred after recruitment to avoid selection bias. Randomisation (stratified by LGA) was conducted by an independent statistician.
Blinding (performance bias and detection bias) All outcomes	High risk	Staff measuring height and weight were not blinded to intervention status because they also delivered the intervention. All dietary recalls, data entry, and analyses were conducted with staff blinded to participant’s group allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low attrition (88% completed) and balanced between groups. In addition, participating parents excluded from mid‐intervention analyses (5 months from baseline) due to missing data and loss to follow‐up were more likely at baseline to have low levels of maternal education (57.5% vs 36.1%). Kept at low risk‐ because we are not using data from mid‐intervention analysis.
Selective reporting (reporting bias)	Low risk	Protocol seen. All outcomes reported
Other bias	Unclear risk	Insufficient details reported to assess risk of contamination
Other bias‐ timing of recruitment of clusters	Low risk	Randomisation of first‐time parents’ groups (clusters) occurred after recruitment to avoid selection bias.