Perry 1997.

Study characteristics
Methods	Trial name: Child and Adolescent Trial for Cardiovascular Health (CATCH) Study design: cluster‐RCT Intervention duration: 3 years; 1991–1994 Length of follow‐up from baseline: follow‐up of the schools and students took place in the spring of 1992, 1993 and 1994. Differences in baseline characteristics Schools: among 96 schools measured at baseline, there were no significant differences between the study conditions for all relevant variables, insuring equivalency between groups. All 96 schools maintained their participation in their allocated treatment condition over the 3‐year study. Students: no significant differences by site, gender or ethnic group between those who did and did not participate. Unit of allocation: schools Unit of analysis: classrooms and schools
Participants	School type: elementary schools Region: CATCH was implemented in 4 study centres: San Diego, California; New Orleans, Los Angeles; Minneapolis, Minnesota and Austin, Texas, USA Demographic/socioeconomic characteristics: students were from ethnically diverse backgrounds and from geographically diverse areas. Inclusion/exclusion criteria Inclusion of schools ‐ Distance from 1 of the 4 study centres ‐ Ethnic diversity ‐ Food service characteristics (potential for intervention) ‐ Commitment to offering ≥ 90 minutes of PE per week ‐ Commitment to participating in a 3‐year study ‐ Co‐operation with random assignment Inclusion of students ‐ In third grade at beginning of trial ‐ Parents and students agreed to provide a blood sample at baseline Number of schools allocated: 96 from 12 districts Numbers by trial group n (controls baseline) = 40 n (controls follow‐up) = 40 n (interventions baseline) = 56 n (interventions follow‐up) = 56 The intervention schools were further randomised into 2 equal subgroups n School‐based only (baseline) = 28 n School‐ and family‐based (baseline) = 28 n School‐based only (follow‐up) = 28 n School‐ and family‐based (follow‐up) = 28 Recruitment: school district superintendents received a letter describing the project and inviting their school district to participate in the study beginning in autumn 1991. While the recruitment process differed among sites, the next step usually involved a personal meeting between a school district representative (e.g. superintendent, curriculum specialist or other district level person) and the principal investigator and site intervention co‐ordinator. After the initial meeting, the necessary decision‐making procedures were followed for each school district indicating interest in participating in CATCH. School districts: of the 15 school districts initially contacted among the 4 sites, 12 chose to participate in the study. In Louisiana, 2/6 school districts declined due to teacher strikes. In Minnesota, 1 district declined due to competing district‐wide commitments. Schools: following recruitment of districts schools within districts were contacted. Students:not reported Recruitment rate School districts: 12/15 Schools:of the 162 schools contacted, 96 agreed to participate (59.3% recruitment rate). Student:total baseline 5106 (60.4%)
Interventions	Number of experimental conditions: 3 (2 intervention: 1 control) The schools were randomised to either intervention (56 schools; 14 per field centre) or control status (40 schools; 10 per field centre). Randomisation occurred after all baseline measurements were completed. The intervention schools were further randomised into 2 equal subgroups: 1 group received a school‐based programme consisting of school food service modifications, PE and the CATCH curricula (28 schools; 7 per field centre); the other group received the same school‐based programme plus a family‐based programme (28 schools; 7 per field centre). Policies, practices or programmes targeted by the intervention School level 1. EATSMART ‐ To reduce the total fat content of food served to 30%. ‐ To reduce the total sodium content to 600–1000 mg per serving. ‐ Recommendations to lower the total cholesterol in foods offered. 2. CATCH PE ‐ Increase the amount of PE time that students spent in MVPA to 40% of class time. Implementation strategies EPOC: educational meetings ‐ Staff received training sessions to deliver EATSMART and CATCH PE. EPOC: educational outreach visits ‐ Staff received ongoing support visits to implement EATSMART/CATCH PE. EPOC: educational materials ‐ Educational materials were provided to staff/schools for EATSMART and CATCH PE. ‐ Smart choices manual was provided to all schools. EPOC: other ‐ Families were engaged by Family Fun Nights and home curricula Theoretical underpinning: Social Learning Theory and Organisational Change Description of control: the control group received their usual health curricula, PE and food service programmes, but none of the CATCH interventions.
Outcomes	Outcome relating to the implementation of school service policies, practices or programmes ‐ Mean % of kilocalories from fat in lunches ‐ Mean milligrams of sodium in lunches ‐ Cholesterol milligrams in lunches (mean) ‐ Quality of PE lesson % of 7 activities observed Data collection method Nutrient content of school lunches: nutrient content of school lunches: 5 consecutive, non‐ randomly selected days of school menu, recipe and vendor product information were collected from each intervention and control school. School food service managers were instructed by trained and certified CATCH evaluation staff to keep a written record of lunch menus as well as the portions served each day. At the end of the 5‐day, CATCH evaluation, staff conducted in‐person interviews with the managers and cooks about the menus and recipes using standardised probes for ingredients and preparation methods. Nutrient and ingredient information for vendor products (i.e. foods purchased preprepared) were collected from the food companies. Data entry and nutrient calculations for school menu data at each interval were performed using the Minnesota Nutrition Data System (NDS) Version 2.2. Quality of PE lesson:direct observation Validity of measures used Nutrient content of school lunches: not reported (measures not objective) Quality of PE lesson: not reported; however, the measure used was objective. Outcome relating to cost: not reported Outcome relating to adverse consequences: growth and nutritional quality of the school meals Data collection method: measurements of height and nutrient intake as described in implementation outcomes were collected. Validity of measures used: not reported Outcome relating to child diet, PA or weight status: child diet, PA and anthropometry Data collection method Child diet: a 24‐Hour Dietary Recall measured total daily food and nutrient intake in a random subsample of 30 students per school at both baseline and follow‐up. A non‐quantified food record was completed by students on the previous day and was used as a prompt for the interviewer who conducted the 24‐hour recall. The data were directly entered into a laptop computer during the interview and the NCC database was used for evaluation. Self‐reported child PA: the Self‐Administered Physical Activity Checklist (SAPAC). Fitness: 9‐minute distance run. Fitness other: SOFIT Height, weight and triceps and subscapular skin‐folds: measured using the Stadiometer, a balance scale and Lange calipers. Skinfold thickness was measured 3 times at each site, with intraclass correlation coefficients exceeding 0.97. Height was measured to the nearest 0.1 cm, weight to the nearest 0.1 kg, and the skin‐folds to the nearest mm. BMI was defined as weight kg divided by height in metres squared. Validity of measures used Child diet: method had previously been shown to be reliable and valid. Self‐reported child PA: validated Fitness: objective Fitness other: objective Child PA: validated Anthropometry: objective
Notes	Note: study targeted PA, nutrition and tobacco; however, implementation outcomes for tobacco were unavailable and as such, this was reported as a nutrition and PA only trial, with their corresponding implementation outcomes and strategies only reported. A variety of outcomes pertaining to programme implementation were reported across the published reports of the CATCH intervention. There was some inconsistency in the reported key implementation policies and practices targeted by the programme. Given this, implementation outcome data were extracted from the study published by Perry and colleagues as the objective of this paper was specifically to report on programme implementation and measures including intervention 'fidelity'. Research funding: National Heart, Lung and Blood Institute (U01HL 33927, UOI HL 39852, UOI HL 39870, UOI HL 33906, UOI HL 39880). Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Schools were randomly allocated to experimental group. Random sequence generation procedure not described.
Allocation concealment (selection bias)	Unclear risk	No information provided about allocation concealment and, therefore, it was unclear if allocation was concealed.
Blinding of participants and personnel (performance bias) Implementation outcome	High risk	Outcome group: no blinding to group allocation of participants or personnel described and this was likely to influence performance. Outcome: child BMI Low: objectively measured Outcome: nutritional quality (adverse effects) High: self‐reported data
Blinding of outcome assessment (detection bias) Implementation outcome	High risk	Outcome group: no mention that observers were blinded to group allocation and, therefore, the risk of detection bias was high. Outcome: BMI (objective measure) Low: blinding would not impact objective measure. Outcome: nutritional quality (adverse effects) High: self‐reported data
Incomplete outcome data (attrition bias) Implementation outcome	Low risk	Outcome group: all outcomes None of the schools dropped out or refused to participate in the intervention activities. Tracked down students who were loss to follow‐up and living within 100 miles to obtain measurements and enable measurement according to ITT principles. No mention of ITT analysis in manuscript.
Selective reporting (reporting bias)	Unclear risk	No study protocol, therefore, it was unclear if there was selective outcome reporting.
Other bias	Low risk	Did not appear to be at risk of contamination or other biases.
Recruitment to cluster	Low risk	Individuals within each randomised cluster participated.
Baseline imbalance	Low risk	Schools were randomly allocated to condition and so risk of baseline imbalance was low.
Loss of cluster	Low risk	None of the schools dropped out or refused to participate in the intervention activities.
Incorrect analysis	Low risk	The analysis appeared appropriate.
Compatibility with individually randomised RCTs	Unclear risk	Unable to determine if a herd effect existed.
Overall risk of bias assessment	Low risk	Most domains were at low risk of bias.