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DeBar L, Dickerson J, Clarke G, Stevens V, Ritenbaugh C, Aickin M. Using a website to build community and enhance outcomes in a group, multi-component intervention promoting healthy diet and exercise in adolescents. Journal of Pediatric Psychology 2009; 34 (5): 539-550.

PubMed ID: 19091807
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
NEUTRAL: See Research Design and Implementation Criteria Checklist below.
Research Purpose:

To test the efficacy of a health plan-based, two-year lifestyle intervention to increase bone mineral density and prevent bone loss in female adolescents.

Inclusion Criteria:

The study population for the YOUTH (Youth, Osteoporosis and Understanding Total Health Project) trial was fully described in a previously published paper. In this paper, the sample was briefly described as:

  • 14-16 years of age
  • Female
  • Age and gender adjusted body mass index (BMI) values below the national median
  • Enrolled in an HMO in the Pacific Northwest.
Exclusion Criteria:
  • BMI at or above the age and gender adjusted national median
  • Age less than 14 years or greater than 16 years.
Description of Study Protocol:


  • Teenage girls who were members of the targeted HMO meeting age and BMI criteria, were mailed YOUTH trial invitations
  • Follow-up phone calls were made by research staff.


  • YOUTH is a randomized controlled trial consisting of a multi-component lifestyle intervention
  • The current paper focuses on one element of the intervention; the study website.

Blinding Used

The study included a randomized control condition of participants who used a parallel website with the same design, look and feel as the intervention site, but did not include any section emphasizing study-specific lifestyle targets or personalized feedback about behavioral goal attainment. Subjects were blinded to the intervention or control assigned.


The YOUTH trial intervention aimed to increase consumption of calcium and fruits and vegetables and increase physical activity involving high impact and weight-bearing activities. Participants were encouraged to:

  • Consume 1,350mg per day of calcium
  • Consume eight servings of fruits and vegetables per day
  • Participate in both 20 minutes of high impact exercise and 10 minutes of strength training twice per week
  • Participate in in-person components of the intervention (overnight retreat and monthly events)
  • Use the study website at least once per week for the duration of the two-year study.

Statistical Analysis

  • Comparisons of Internet usage patterns, demographics, study adherence to the larger PCT and baseline behavioral characteristics between the three levels of web use (infrequent, intermittent and consistent) were conducted using ANOVAs for continuous variables and chi-square analyses for categorical variables
  • The relationship between dietary and physical activity outcomes and tracked website use were fitted into a random effects model. Logit models were used for dichotomous variables and linear models were used for continuous dependent variables
  • Models were constructed to analyze website use and intervention target outcomes, which included baseline measures, demographics and adherence to other elements of the intervention as covariates. 
Data Collection Summary:

Timing of Measurements

  • Diet and exercise data was collected through three unannounced 24-hour diet and 72-hour exercise phone recalls. Follow-up phone recalls were conducted every two months throughout the study
  • Website usage was measured by an automated tracking system and self-reported questionnaire administered at the 12-month follow-up visit
  • In-person intervention session attendance was used to measure overall participant adherence
  • Measures of bone mass density, urinary and blood markers of bone turn-over, strength measurements and general health questionnaires were used in the YOUTH trial, but not reported in this paper.

Dependent Variables

  • Calcium intake (mg per day)
  • Fruit and vegetable intake (servings per day)
  • Soda intake (ounces per day)
  • Cola intake (ounces per day)
  • High-impact activity (minutes per week)
  • Strength/weight training (minutes per week)
  • Combined activity target.

Independent Variables

  • Website usage (via automated tracking system) was split into three categories:
    • Infrequent use (logging in not more than one of the four-month tracking segments)
    • Intermittent (logging in during two to three of the six study segments)
    • Consistent (logging in during at least four of the six study segments)
  • Total number of website visits
  • Total number of intervention-related website hits.

Control Variables

  • Team meeting attendance
  • Number of self-monitoring postcards returned.
Description of Actual Data Sample:
  • Initial N: 82 girls receiving the intervention were reported on in this paper (this excludes 86 participants randomized to the comparison condition and 41 participants enrolled before the website was fully operational)
  • Attrition (final N): All 82 girls are included in the analysis
  • Age: 14-16 years old
  • Ethnicity: 80.5% white
  • Other relevant demographics:
    • 78.9% of participant's mothers reported post-secondary education
    • Median annual household income was $68,656 (SD $31,395; range $10,000-$125,000) 
  • Anthropometrics: No differences noted in anthropometric measures at baseline between website usage groups
  • Location: Pacific Northwest Region, United States.


Summary of Results:

Key Findings

  • Overall website use was associated with increases in calcium intake [for untransformed DV: β=69.72, P=0.01, effect size (ES)=0.15]
  • Overall website use was associated with higher levels of high-impact activity (for untransformed DV: β=10.93, P=0.04, ES=0.13)
  • Specific use of the study website related to behavioral feedback and communications did not show significant associations with behavioral outcomes
  • The most frequently reported reason for visiting the study website was to check the number of incentive points earned and to learn new information
  • The most visited website pages had content related to incentive points, caption contests and fun facts.
Author Conclusion:
  • The results suggest a significant, but modest, association between overall study website use and improvements in key study behavioral targets (calcium consumption, high impact activity)
  • The study website was only a single element of a multi-component intervention that included several in-person visits. It is less surprising that this Internet element accounted for just a modest proportion of the overall change in primary outcome. It is of note, however, that the findings held up when controlling for adherence to in-person intervention sessions, suggesting that the study website had an intervention effect above and beyond that of overall adherence to intervention elements of the study.
Reviewer Comments:
  • Study design, intervention design and primary outcomes were reported elsewhere and not duplicated in this paper. Key aspects of the study design are unclear
  • The method of randomization was not reported (randomized to use the actual website or an alternative website)
  • Data from the control group (alternate website used) was not published in this paper for comparison (it is unknown whether use of the alternative website lead to similar, modest increases in outcome variables)
  • The study was not powered to obtain significant findings for web elements
  • The demographic of the sample may limit the extent to which the results can be generalized (mostly white, came from well-resourced households with high levels of parental post-secondary education).

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?

Copyright American Dietetic Association (ADA).