Activity 3

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To determine the effectiveness of the 12-week workplace intervention on energy intake, weight, physical activity and cardiovascular disease risk and the effect of delivery method on outcomes. Four hypotheses were tested:

  • The two directional hypotheses were that the workplace intervention would improve participants' diet, weight and physical activity outcomes (hypothesis 1) and Framingham risk percents as measure of cardiovascular disease risk (hypothesis 2) at weeks 12 and 26
  • The third and fourth hypotheses explored between-group differences: that there would be no significant differences in diet, weight or physical activity outcomes (hypothesis 3) or cardiovascular disease risk (hypothesis 4) between arms.
Inclusion Criteria:
  • Subjects included overweight/obese academic health science center employees
  • Males and females older than age 18 years
  • Minimum BMI of 25.0.
Exclusion Criteria:
  • Pregnant
  • Given birth within the prior three months
  • Breastfeeding.
Description of Study Protocol:


Four 12-week blocks of the intervention were conducted, two for each arm, on two geographically distinct campuses to reduce the risk of contamination. Subjects were recruited via campuswide e-blasts and signs posted on the campuses three weeks prior to the start of each block. Subjects volunteered for enrollment on the basis of campus location.


Prospective nonrandomized clinical trial.

Blinding used

Implied with measurements.


  • 12-week workplace intervention with two modes of delivery, Internet-based or in-person, with follow-up at week 26
  • All subjects received identical intervention content with dietitian visits at baseline and weeks 6, 12 and 26 and live weekly weigh-ins
  • Subjects received personalized diet guidelines for attaining goal weight and improving diet quality on the basis of recommendations of the National Cholesterol Education Program, American Heart Association, and the National Heart, Lung and Blood Institute DASH Diet; a range of 20kcal per kg to 25kcal per kg current weight was used to estimate energy needs for weight loss
  • The study compared the Internet-based intervention to a usual care control group, which was an in-person, face-to-face intervention
  • Those in the in-person arm saw the RD for the 50-minute weekly group sessions at lunchtime, whereas those in the Internet-based arm received the weekly session content and materials via WebCT, which also provided access to email and asynchronous discussion forums with the RD and other Internet-based group participants
  • Materials distributed at in-person weekly sessions were provided to those in the Internet-based weekly sessions as PDFs
  • All subjects received email and telephone reminders before individual appointments and email reminders before weekly sessions.

Statistical Analysis

  • SPSS versions 16.0 and 17.0 were used for data entry and analysis
  • Extreme outliers were identified but not removed for analyses of weight and health-related quality of life (HRQOL)
  • Various power analyses were calculated
  • Descriptive statistics were calculated for all study variables for the total sample and within each group
  • ANOVA with repeated measures at baseline and at weeks 12 and 26 was used to analyze the effect of method of delivery over time.
Data Collection Summary:

Timing of Measurements

  • The first block began in September 2006 and the final block in September 2007
  • All subjects in both arms met with the study RD in person for 90 minutes for baseline anthropometric measures, health and nutrition histories and two 24-hour diet recalls
  • Measurements made at baseline, 12 weeks and 26 weeks.

Dependent Variables

  • Energy intake
  • Weight and body fat measured with Tanita Segmental Body Fat Analyzer
  • Waist circumference
  • Blood pressure measured with automated Omron cuff
  • Glucose and serum lipids measured with a Cholestech LDX Analyzer
  • Physical activity assessed with the International Physical Activity Questionnaire
  • Cardiovascular disease risk-Framingham risk percents
  • HRQOL assessed with CDC Healthy Days Surveillance questionnaire (HRQOL-14)

Independent Variables

12-week workplace intervention delivered via Internet or in-person.

Control Variables

Description of Actual Data Sample:

Initial N: Of 155 subjects screened, 137 were enrolled, 93.4% women

Attrition (final N): 113 (82.5%) completed the intervention at 12 weeks, 95 (69.3%) completed the 26-week follow-up

Age: Mean age 46.5±10.6 years

Ethnicity: 46% white, 54% non-white

Other relevant demographics: Not reported

Anthropometrics: There were no significant differences between arms for baseline characteristics for the 137 subjects enrolled, but of the completers, those in the in-person arm weighed significantly more, had a larger waist circumference and greater body fat as compared with those in the Internet-based group at baseline, which continued throughout the investigation and follow-up

Location: Newark and Piscataway, NJ.

Summary of Results:

Key Findings

  • There was no significant treatment effect based on repeated measures ANOVA
  • All subjects experienced significant reductions in clinical outcome measures at weeks 12 and 26, regardless of intervention medium; there were no between-arm differences for the outcome measures
  • Within subjects, significant main effects indicating improvement were noted at week 12 in weight, waist circumference, body fat, HRQOL and energy intake, and at week 26 in weight, waist circumference, body fat, HRQOL, energy intake and systolic and diastolic blood pressure.
Author Conclusion:

In summary, the results of this academic health sciences center-based workplace intervention trial support federal and professional association initiatives to promote weight-management programs in the workplace. The data indicate that the Internet and IP modes of intervention can successfully improve weight status and health-related quality of life, and reduce risk of chronic diseases. Given the potential efficiency of using the Internet for a workplace intervention, it is feasible to integrate such interventions in multi-site organizations similar to this one, a multi-campus academic institution. The potential organization-wide impact of this intervention may reduce health-care costs, increase productivity and lead to improved health-related quality of life among employees.

Funding Source:
American Heart Association Clinical Research Grant
Other non-profit:
Reviewer Comments:

113 (82.5%) completed the intervention at 12 weeks and 95 (69.3%) completed the 26-week follow-up. There were no significant differences between arms for baseline characteristics for the 137 subjects enrolled, but of the completers, those in the in-person arm weighed significantly more, had a larger waist circumference and greater body fat as compared with those in the Internet-based group at baseline, which continued throughout the investigation and follow-up.

Quality 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) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  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? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? N/A
  3.5. If case control 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.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? ???
  4.1. Were follow-up methods described and the same for all groups? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  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? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  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)? No
  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? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes