TN: Telenutrition Interventions by Registered Dietitians (2012)

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

The objectives of this study were to evaluate weight-loss outcomes and the effect on CVD risk factors, and the resources required (from the perspective of a managed care organization) of the self-help, non-clinical, and clinical approaches to weight control.

Inclusion Criteria:
  • BMI of more than 25 (or a BMI of 24 or more plus one cardiovascular risk factor)
  • Willingness to follow the study protocol, which included a refundable $100 deposit
  • Written informed consent provided.
Exclusion Criteria:
  • Intention to move beyond commuting distance within the next 12 months
  • Medical conditions that would interfere with study participation
  • Unwillingness to follow the study protocol.
Description of Study Protocol:

Recruitment

  • Participants were recruited from the HMO's patient population and from the surrounding community
  • Information about the study was disseminated to patients enrolled in the HMO and in the community using a variety of techniques including newsletter articles, flyers, posters, and local media news coverage via cable television and newspapers.

Design

Randomized controlled trial

Blinding used

Implied with measurements

Intervention

  • Workbook alone intervention (do it yourself) subjects complete self-help sheets
  • Computerized tailoring with touch screen monitors based on Transtheoretical model for behavior change-the subject could select goals that reflected differences in their readiness to make change
  • Computers and staff consult. The staff consultation component included six closed-group workshop sessions and up to 18 telephone or face-to-face consultations with a registered dietitian and/or a cognitive behavioral therapist.

Statistical Analysis

  • Statistical analysis were performed using SAS software
  • One-way analysis of variance was used to compare the three interventions on all normally distributed variables measured at baseline and each of the four quarters
  • When comparisons involved two intervention arms, analysis was by f test adjusted using the Bonferroni method
  • Chi-square was calculated for statistical comparisons of the groups for categorical variables
  • Regression analysis was used to evaluate predictors of weight loss
  • Correlations were calculated to assess the relationship between intervention variables and weight loss and between weight loss and changes in CVD risk factors
  • Analysis of covariance was used to control for differences in baseline values.

 

Data Collection Summary:

Timing of Measurements

  • Staff evaluated the potential use of an outside weight program at three, six, and nine months into the study
  • Medication usage evaluated at baseline, six months and one year. Staff recorded information regarding dose and frequency of use of medications by instructing participants to bring in current prescriptions to their appointments.

Dependent Variables

  • Weight loss was the primary outcome, measured in body weight at baseline and at year one on a balance scale with subjects in light clothing and without shoes
  • Circumference of waist and hip measures were done using the umbilicus
  • Lipid profile was analyzed in a CDC certified laboratory
  • Glucose was assessed at baseline and year one for a change in diabetes
  • Blood pressure was obtained by a certified staff using standard procedures
  • Dietary intake was measured by using the block food frequency questionnaire
  • Physical activity was based on self-report using the Paffenbarger et al. physical activity questionnaire.
  • Medical and weight histories were also assessed
  • Cost data was calculated using national wage rates from Bureau of Labor Statistics
  • All participants were given a self administered anonymous exit survey regarding the opinions of the acceptability of intervention comments.

Independent Variables

  • Three types of interventions:
    • Workbook alone (do it yourself) where subjects completed self-help sheets
    • Computerized tailoring with touch screen monitors based on the Transtheoretical Model for behavior change, the subject could select goals that reflected differences in their readiness to make changes
    • Computerized tailoring plus staff consultations which included six closed group workshop sessions and up to 18 telephone or face to face consults. It encouraged use of a computer to identify problems and issues.

Control Variables

 

Description of Actual Data Sample:
  • Initial N: 919 agreed to participate, 588 were randomized
  • Attrition (final N): 588 total
    • 116 subjects in the workbook only group
    • 236 in the workbook and computer group
    • 236 workbook and computer, plus staff group
  • Age: Mean age 52.2 years
  • Ethnicity: Caucasian
  • Other relevant demographics: Not reported
  • Anthropometrics: Compared with the two computer-based intervention groups, the work-book alone group had a higher mean fat intake (P<0.01) and a larger mean waist measurement (P<0.01) at baseline
  • Location: Albert Einstein College of Medicine, Long Island campus.

 

Summary of Results:

Key Findings

  • The mean energy intake and percent of energy from fat decreased from baseline in all three intervention groups (P<0.01); there was not a statistically significant difference in the mean nutrient intake change by intervention group.
  • All of the groups achieved a statistically significant weight loss. The most intensive intervention group (workbook with computer and staff added) lost significantly more weight than the least intensive (workbook alone) group (F=5.56, P=0.02) The mean weight loss in the intermediate treatment group (workbook and computer) was not significantly greater than the weight loss in the workbook alone control group.
  • The decreases in mean BMIs for these respective intervention levels were 0.4, 0.9 and 1.2.
  • A regression analysis of all participants randomized to the computer treatment condition (computer alone or computer plus staff) showed that more frequent computer usage was highly predictive of weight loss (r2=0.06, F=24.9, P=0.0001).
  • The most intensive intervention group (computer and staff consultation) had a significant increase in the mean HDL cholesterol level (P<0.01) and a decrease in the mean diastolic blood pressure level (P<0.01). There were no significant differences in mean changes in CVD risk variables among the intervention groups.
  • Intervention variables that correlated with weight loss included more computer logons, achieving computer-selected goals, more self-monitoring, increased walking, and decreased energy and fat intake, as well as higher attendance in staff consultation group sessions for that treatment condition.
  • Weight loss correlated with decreases in fasting glucose and blood pressure
  • The total cost of providing each intervention was calculated using each component of the intervention, including the workbook ($11.97), staff time ($15.51 per hour for clerical tasks and $21.15 per hour for professional tasks) and computer costs ($29.44 per participant). The cost of staff time per participant over the 12-month study period was $0.35 for the least intensive intervention (workbook only) group, $0.59 for the intermediate intensive intervention (workbook and computer) group, and $92.33 for the most intensive intervention (workbook, computer and staff) group. For the increasing levels of intervention intensity, the mean 12-month weight losses were 2.2, 4.7 and 7.4 pounds, with the respective cost of the intervention per participant being $12.33, $41.99 and $133.74; mean costs per pound lost were $6.23 for the workbook only group, $8.57 for the intermediate intensive intervention group, and $18.78 for the most intensive intervention group.   

 

Author Conclusion:

Dietitians and other health professionals should consider using computer-based communications to maintain frequent contact, promote self-monitoring, and tailor behavioral goals. In a weight-loss program, computers can facilitate selecting behavioral change goals.

Funding Source:
Government: NHLBI Grant # R01 HL50372 and Diabetes Research and Training Center # R01 DK20451
Reviewer Comments:

Groups had statistically significant differences at baseline: Compared with the two computer-based intervention groups, the work-book alone group had a higher mean fat intake (P<0.01) and a larger mean waist measurement (P<0.01).

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? ???
  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? ???
  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? Yes
  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? Yes
  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? No
  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? Yes
  6.6. Were extra or unplanned treatments described? Yes
  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)? No
  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? ???
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
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