Increase Font Size Decrease Font Size View as PDF Print

Nader PR, Sellers DE, Johnson CC, Perry CL, Stone EJ, Cook KC, Bebchuk J, Luepker RV. The effect of adult participation in a school-based family intervention to improve children's diet and physical activity: The Child and Adolescent Trial for Cardiovascular Health. Prev Med. 1996; Jul-Aug: 25(4): 455-464.


PubMed ID: 8818068
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:

To do a dose analysis of the family component of the Child and Adolescent Trial for Cardiovascular Health (CATCH) study by assessing the effect of the level of adult participation.

Inclusion Criteria:
  • Student participation measures: Any student who attended a school-plus-family intervention during the three years of the study. Assessment of the rate of return of the activity cards is based only on those curricula in which a student took part. 
  • Family program dose analysis: Only students who attended a CATCH school-plus-family intervention school during each of the three years of the study. 
Exclusion Criteria:

The Unpuffables were excluded because the end points of primary interest in this paper measure physiological, behavioral and psychosocial factors related to eating and physical activity, rather than to smoking. 

Description of Study Protocol:


Nothing explicitly discussed; it was assumed to be discussed in other CATCH studies.


  • Secondary analysis included students who attended a CATCH family intervention school during all three years of the study. The extent of the adult-child interaction was measured by the number of activity packets that an adult household member completed with the child. 
  • 96 elementary schools were randomized to one of two groups: An intervention group (56 schools, 14 per field center) and a control group (40 schools, 10 per center). The intervention group was further randomized into two equal subgroups; one group received the school-only program consisting of the classroom curricula, school food service intervention and school physical education interventions (28 schools, seven per field center). The other group (school plus family) received the school-based interventions plus the family component interventions (28 schools, seven per field center). The CATCH interventions were delivered to schools and to students beginning in the 1991 to 1992 school year (third grade) and progressed through the 1993 to 1994 school year (fifth grade). Control schools received the usual, if any, health education programs, but no CATCH intervention.
  • Measurements of school and student level behavioral outcomes were made at baseline, beginning in third grade, and each spring in third through fifth grades. Physiologic measures were performed on students at baseline and at the end of fifth grade.  

Dietary Intake/Dietary Assessment Methodology

  • The health behavior questionnaire (HBQ) was a class-administered 45-minute instrument designed to evaluate factors associated with diet and exercise. HBQ included psychosocial data on dietary knowledge, intentions, usual food choices, social reinforcement and support and self-efficacy. HBQ was administered to all third graders during the fall (baseline) and the spring of the first year of the CATCH study, to fourth graders during the spring semester of the second year of CATCH and to fifth graders during the spring semester of the third year of CATCH. The reliability and validity of the instrument, assessed during the pilot phase of CATCH and with the baseline data were found to be adequate.  
  • A 24-hour dietary recall recorded total daily food and nutrient intake in a sample of 30 students per school measured at both baseline (third grade) and follow-up (fifth grade). 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. Parents were contacted by telephone to clarify or add information as necessary. The data was directly entered into a laptop computer during the interview. The Nutritional Coordinating Center database was used for evaluation. Three measures from this instrument, percentage of calories from fat, percentage of calories from saturated fat and sodium intake per 1,000 calories were examined in this analysis because they were key nutrients of interest for risk reduction. 
  • Total cholesterol was examined in this analysis, collected at baseline and during the fifth grade. Non-fasting venipuncture samples were drawn, samples were centrifuged, and serum was sent to a central laboratory for analysis. Total cholesterol was determined by the enzymatic method on a Beckman CX4 autoanalyzer. 


  • Activity packets created to encourage parent-child interaction at home around eating and exercise topics
  • The purpose of the CATCH home/family component was to reinforce at home the concepts, activities and skills of the classroom curriculum. The conceptual model guiding the development of materials was derived from social cognitive theory and specifically targeted environmental, personality and behavioral factors that are likely to influence adoption of healthier eating and physical activity behaviors. The format was a take-home packet of learning materials and activities to be completed jointly by the child and a parent or adult figure in the home. Rewards were given for completed lessons that were returned, and the system of reward and record-keeping also provided a means of tracking participation of the home and family. 
  • Four home-based curricula were implemented. These included, in the third grade, Hearty Heart Home Team (five activity packets distributed weekly); in the fourth grade, Stowaway to Planet Strongheart (six weekly activity packets); in the fifth grade, Health Trek....The Journey Continues (four tip sheets); and at the end of the fifth grade, The Unpuffable (four weekly activity packets about smoking). The activity packets were distributed each week to students and differed in format and content, depending on the grade level. The activity packets contained a story to be read by all household members followed by a series of activities to be completed at home, including healthy recipes, family physical activities, myths about smoking, games and goal-setting. The refrigerator tip sheets, which were distributed with magnets for refrigerator display, had summaries of healthy diets and activities to complete. Students brought back to school cards on which parents and students indicated the activities they had completed. Participation in the home curricula was encouraged by incentives such as pencils, memo pads and certificates. 
  • The family component also included two Family Fun Nights, Hearty's Party and Strongheart Celebration, which were events that third- and fourth-grade students and their families were invited to attend. These 1.5- to two-hour events, which consisted of prizes, games and activities in the format of a fair, took place in either a gym, auditorium or a school play area. The purpose of the event was to raise awareness of the goals and skilled contained in CATCH in a relaxed and fun environment. Parents, classroom teachers, physical education specialists and food service personnel, along with CATCH staff, served as volunteers to decorate and run the booths, provide guides and clean up. Class rosters were utilized at registration to record participation rates. 

Statistical Analysis

  • Multiple regression analysis was used to assess the association of adult participation with the child's knowledge, attitudes and behaviors related to diet and physical activity
  • The main effect of the dose and the interaction between dose and gender, race and gender-by-race were examined using P=0.05 as the critical value. 
Data Collection Summary:

Timing of Measurements

  • The CATCH interventions were delivered to schools and to students beginning in the 1991 to 1992 school year (third grade) and progressed through the 1993 to 1994 school year (fifth grade). Control schools received the usual, if any, health education programs, but no CATCH intervention.
  • Measurements of school and student level behavioral outcomes were made a baseline, beginning in third grade, and each spring in third through fifth grades. Physiologic measures were performed on students at baseline and at the end of fifth grade.  

Dependent Variables

In the mixed-model regression analysis, the dependent variable is the final follow-up (semester six) value of the outcome measure. 

Independent Variables

In the mixed-model regression analysis, the independent variable of interest is the continuous measure of dose, adult participation in the family program, which ranged form zero to 15. 

Control Variables

  • For every outcome, gender of the child, ethnicity of the child and CATCH size were also included as fixed effect covariates, and school, nested within site, as a random effect covariate
  • For the 24-hour recall measures, the number of meals at baseline and the number of meals at follow-up were also included as fixed effect covariates. Similarly, height and body mass index were included as covariates for cholesterol
Description of Actual Data Sample:
  • Initial N: 96 elementary schools
  • Attrition (final N):
    • The number of students who attended a CATCH school-plus-family school during the three years of the study was 3,663. Of these students, 46.7% (N=1,711) attended a CATCH family school for the entire three-year study period
    • Analyses were limited to 1,631 Caucasian, Hispanic or African-American students who attended a family school for the full three years of study and was limited to a subset of students among these 1,631 who provided information for that measure during the baseline and the final follow-up period as well as the other independent variables
    • Since the 24-hour dietary recall measures were collected from only 30 students per school, the number of students who were in a family intervention school all three years and were in the sample of students selected for 24-hour recall measure is more limited.
  • Age: Third through fifth graders
  • Ethnicity: About 4.7% of the students who attended a CATCH family school throughout the field trial were from racial and ethnic groups other than Caucasian, Hispanic or African American
  • Location: Texas, California, Louisiana and Minnesota.
Summary of Results:


  • Implementation of the program: 
    • Classroom sessions: Teachers completed nine of the 10 activities related to the family components
    • Family Fun Nights: Every school held one; teacher attendance was relatively high in states were multiple nights were not held. Most students at all four sites brought two family members with them. 90% of the activities that were suppose to be offered at these nights were offered.
    • Average rate of return for activity cards was highest in MN (79%) and in the other three states ranged from 60% to 66%
  • Outcomes of the program: Statistically significant results suggested that dose effects were found for knowledge and attitudes related to diet and physical activity. These effects were more pronounced for minority and male students.
Outcome Measure


Zero to Three


Four to Six


Seven to Nine


10 to 12


13 to 15


Risk factor, cholesterol (mg)  

168.5 (3.2; 63)

170.6 (2.1; 123)

169.3 (2.0; 157) 

167.8 (1.9; 239)

170.3 (1.6; 318)


24-hour recall, sodium (mg)

1,595.4 (98.1; 21)   1,502.6 (64.3; 47)

1,532.8 (74.1; 60)

1,427.6(44.7; 86)

1,512.0 (38.6; 122) 


24-hour recall, calories from total fat (percentage) 

32.0 (1.4; 21)

30.8 (0.8; 47)  30.8 (0.8; 60) 29.1 (0.8; 86) 31.0 (0.6; 122)  336 

24-hour recall, calories from saturated fat (percentage) 

12.4 (0.8; 21) 11.9 (0.4; 47)  11.8 (0.4; 60) 10.5 (0.4; 86) 11.1 (0.3; 122)  336 

Self-reported physical activity, vigorous minutes (before and after) 

48.7 (5.8; 130)   57.2 (5.1; 206) 

58.6 (4.8; 238)

43.5 (3.3; 377)

41.7 (2.6; 491)


Health behavior questionnaire (HBQ), dietary knowledge 

9.4 (0.5; 123) 10.3 (0.4; 202) 

11.3 (0.2; 236)

10.9 (0.2; 368)

11.1 (0.2; 438)

HBQ dietary intentions 0.5 (0.6; 114)  1.6 (0.5; 194)

1.5 (0.4; 229) 

1.5 (0.4; 360)

2.0 (0.3; 476)

HBQ usual food choice  -05 (0.7; 117)

0.3 (0.5; 193) 

0.5 (0.5; 234) 

1.3 (0.4; 360)

1.1 (0.3, 472)

HBQ food choice, parental reinforcement 

1.7 (0.4; 116) 

2.1 (0.3; 185)

2.1 (0.3; 220)

2.3 (0.2; 352)

2.9 (0.2; 459)


HBQ food choices, teacher reinforcement

 3.9 (0.5; 111)

4.1(0.3; 177)

3.8 (0.3; 215)

3.8 (0.2; 351)

4.2 (0.2; 452)

HBQ food choices, friends reinforcement

-2.0 (0.4; 111)

-1.6 (0.4; 175)

-1.6 (0.3; 210)

-1.5 (0.3; 345)

-1.9 (0.2; 452)

HBQ food choices, social reinforcement  2.5 (1.0; 109)

4.5 (0.8; 172)

4.5 (0.7; 204)

4.5 (0.6; 336)

5.3 (0.5; 439)

Dietary self-efficacy 

5.5 (0.7; 109)

5.6 (0.5; 191)

6.5 (0.4; 230)

6.9 (0.4; 342)

6.8 (0.3; 461)

Physical activity, positive support 

5.5 (0.4; 117)

5.1 (0.3; 188)

5.8 (0.3; 229)

6.1(0.2; 362)

6.5 (0.2; 472)

Physical activity, negative support

5.2 (0.2; 119)

4.7 (0.2; 190)

5.2 (0.2; 233)

5.3 (0.1; 365)

5.3 (0.1; 480)

Physical activity, self-efficacy

2.7(0.2; 117) 

2.7 (0.2; 203)

2.9 (0.1; 233) 

3.1 (0.1;  358) 

3.0 (0.1; 484) 



Author Conclusion:
  • The family component of CATCH was implemented as intended. The secondary analyses suggest the level of adult participation, or the dose of the family program, may be related to the attitudes, knowledge and beliefs, but not the behavior, of the students in the CATCH school-plus-family intervention. 
  • For all students, parent's reinforcement of food choice and positive support for physical activity increased as adult participation increased. For minority students, both physical activity, self-efficacy and dietary self-efficacy increased as adult participation increased. For minority boys, dietary knowledge increased as adult participation increased. 
Reviewer Comments:

Unadjusted values illustrated in the tables.

Research Design and Implementation Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to nutrition or dietetics practice?
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies)
Validity Questions
1. Was the research question clearly stated?
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated?
  1.3. Were the target population and setting specified?
2. Was the selection of study subjects/patients free from bias?
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?
  2.2. Were criteria applied equally to all study groups?
  2.3. Were health, demographics, and other characteristics of subjects described?
  2.4. Were the subjects/patients a representative sample of the relevant population?
3. Were study groups comparable?
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?
  3.3. Were concurrent controls used? (Concurrent preferred over historical controls.)
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?
  3.5. If case control or cross-sectional study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable. Criterion may not be applicable in some cross-sectional studies.)
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?
4. Was method of handling withdrawals described?
  4.1. Were follow-up methods described and the same for all groups?
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for?
  4.4. Were reasons for withdrawals similar across groups?
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study?
5. Was blinding used to prevent introduction of bias?
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status?
  5.5. In diagnostic study, were test results blinded to patient history and other test results?
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were intervening factors described?
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied?
  6.2. In observational study, were interventions, study settings, and clinicians/provider described?
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured?
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described?
  6.6. Were extra or unplanned treatments described?
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?
  6.8. In diagnostic study, were details of test administration and replication sufficient?
7. Were outcomes clearly defined and the measurements valid and reliable?
  7.1. Were primary and secondary endpoints described and relevant to the question?
  7.2. Were nutrition measures appropriate to question and outcomes of concern?
  7.3. Was the period of follow-up long enough for important outcome(s) to occur?
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?
  7.5. Was the measurement of effect at an appropriate level of precision?
  7.6. Were other factors accounted for (measured) that could affect outcomes?
  7.7. Were the measurements conducted consistently across groups?
8. Was the statistical analysis appropriate for the study design and type of outcome indicators?
  8.1. Were statistical analyses adequately described and the results reported appropriately?
  8.2. Were correct statistical tests used and assumptions of test not violated?
  8.3. Were statistics reported with levels of significance and/or confidence intervals?
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?
  8.6. Was clinical significance as well as statistical significance reported?
  8.7. If negative findings, was a power calculation reported to address type 2 error?
9. Are conclusions supported by results with biases and limitations taken into consideration?
  9.1. Is there a discussion of findings?
  9.2. Are biases and study limitations identified and discussed?
10. Is bias due to study’s funding or sponsorship unlikely?
  10.1. Were sources of funding and investigators’ affiliations described?
  10.2. Was the study free from apparent conflict of interest?