DM: Effectiveness of MNT Provided by RD/RDN (2015)

Study Design:
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Quality Rating:
Research Purpose:

The purpose of this study was to examine the changes in waist circumference and body mass index in older adults enrolled in a diabetes telemedicine program. 

Inclusion Criteria:
  • Aged at least 55 years
  • Current Medicare beneficiaries
  • Diagnosis of diabetes
  • Domicile in a federally-designated medically under-served area
  • All participants provided written informed consent.
Exclusion Criteria:
  • Moderate or severe cognitive deficits
  • Significant visual impairments
  • Renal failure
  • Severe comorbid disease.
Description of Study Protocol:
  • Recruitment: Subjects were Medicare beneficiaries enrolled in the upstate New York IDEATel project from January 2001 to January 2005
  • Design: Randomized controlled trial
  • Blinding used: Data were collected at baseline and annual evaluation visits by personnel not involved in the technical or clinical aspects of the intervention and blinded to randomization status.


  • Participants were randomized to the Intervention or Usual Care Group, within clusters defined by participating primary care providers patient panels
  • Usual care was determined by the primary care providers.

Statistical Analysis

  • Longitudinal mixed fixed and random effects models were used to examine the direct effects of the intervention on BMI, WC and self-reported diet and exercise practices and behavior to examine the influence of gender on the two main outcomes
  • Repeated measures mixed-model path analyses were performed to examine the indirect longitudinal effects of the intervention on BMI and WC through diet and exercise
  • Proc Mixed was used to adjust for clustering within primary care practices and for heterogeneity in cluster and residual variances
  • Random effects were used to model the design features of subjects nested within primary care practices
  • Up to three waves of data were included in an intent-to-treat analysis with all patients having at least one wave of data analyzed
  • A maximum likelihood approach was applied for estimation using mixed models
  • Analyses was performed using SAS.
Data Collection Summary:

Timing of Measurements

Changes in waist circumference, BMI, diet and exercise behaviors and knowledge were examined at baseline and 12 and 24 months.

 Dependent Variables

  • Change in body mass index (BMI) and waist circumference: Weight taken at baseline on a platform balance scale, height taken at baseline on a stadiometer and waist circumference measured with anthropometric tape
  • Diet and exercise measure combined items from validated instruments. 13 items were summed to obtain a total score. Items were prorated to account for missing data.
  • Diet and exercise questions were coded such that a high score indicated less self-reported knowledge and abilities to follow best practices related to diet and exercise.

Independent Variables

  • Telemedicine intervention
    • Subjects were trained to use a home telemedicine unit
    • A nurse case manager conducted home video visits to help patients with diabetes self-management techniques and problem-solving strategies
    • After an initial one-hour nutrition assessment and counseling video visit, 30-minute follow-up video visits were scheduled with the RD every other month
    • Counseling was not individualized and written education materials including sample meal patterns were sent via the secure messaging system.
  • Usual Care Group.
Description of Actual Data Sample:
  • Initial N: 890 Medicare beneficiaries at baseline. 447 in telemedicine and 443 in usual care.
  • Attrition (final N): 746 respondents with at least one follow-up. At Year One, there were 365 in telemedicine and 367 in usual care; at Year Two, there were 213 in telemedicine and 225 in usual care.
  • Age: At baseline, the mean age was 71.02±7.07 years
  • Ethnicity: Not described
  • Other relevant demographics: There were no significant differences in baseline characteristics between the participants randomized to receive telemedicine or usual care
  • Anthropometrics: Mean BMI was 33.31±7.05kg/m2 and mean WC was 111.32±17.56cm. 91.8% of the participants had a BMI of more than 25kg/m2 and 65.8% had a BMI of  30kg/m2 or higher.
  • Location: New York State.
Summary of Results:

Key Findings

  • Telemedicine participants increased their diet and exercise knowledge over time (P<0.001)
  • In adjusted models, the longitudinal direct effect of the intervention on BMI (P=0.633) and WC (P=0.602) was not significant
  • A significant direct longitudinal effect of the intervention on diet and exercise was observed (P=0.002)
  • Women in the Telemedicine Group were significantly more likely than women in the Usual Care Group to decrease WC (P=0.02), but not BMI over time
  • Over the two-year period, it was estimated that women in the Telemedicine Group decreased their WC by 1.2cm, whereas women in the Usual Care Group increased their WC by almost one cm (P=0.02).

 Other Findings

  • Although the direct effect of the intervention on BMI was not significant, the indirect effects of the intervention through diet and exercise on BMI were significant
  • Formal testing of mediation effects demonstrated at least partial mediation of the telemedicine intervention through diet and exercise for both BMI (P=0.004) and WC (P=0.006).
Author Conclusion:

A diabetes telemedicine intervention using televisits for medical nutrition therapy and case management improved nutrition and physical activity knowledge and practices leading to reduced waist circumference and BMI in older people living in underserved rural areas.

Funding Source:
Government: Cooperative Agreement 95C-90998 from CMS
Reviewer Comments:

The authors acknowledged several limitations in this study.

  • First, most subjects were overweight or obese and the project was not designed as a weight-loss study
  • Second, measures of health behaviors including physical activity were obtained by self-report
  • Finally, there was considerable loss to the second follow-up and frequency of contacts were not tracked.
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? No
  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? No
3. Were study groups comparable? Yes
  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? Yes
  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? Yes
  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? ???
  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? ???
  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)? Yes
  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? N/A
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