MNT: Comparative Effectiveness of MNT Services (2009)


Heller SR, Clarke P, Daly H, Davis I, McCulloch DK, Allison SP, Tattersall RB. Group education for obese patients with type 2 diabetes: greater success at less cost. Diabetic Medicine. 1988; 5: 552-556.

PubMed ID: 2974778
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To find out whether group teaching by nurses and dietitians would be better than routine clinic care in the dietary management of newly diagnosed obese middle-aged diabetic patients.

Inclusion Criteria:
  • Newly diagnosed obese type 2 diabetic patients
  • Overweight [body mass index (BMI) more than 27]
  • Aged 30 to 75 years
  • Diabetes was defined as a random blood glucose over 11mmol per L in symptomatic patients or a blood glucose over 11mmol per L two hours after a 75g oral glucose load in those who were asymptomatic.
Exclusion Criteria:
  • Ketonuria
  • Those in whom the diagnosis had been made as an inpatient.
Description of Study Protocol:


All newly diagnosed diabetic patients referred to the University Hospital over an 18-month period were potential study entrants.


Randomized controlled trial. Randomization methods not described.


  • Patients were randomized to usual "unstructured" clinic care or to group education by diabetes specialist nurses and a dietitian
  • Usual Clinic Care patients were seen at their first visit by a doctor and then referred to a dietitian who saw them individually. Patients could be seen more often but for study purposes, measurements and HbA1c were mandatory at visits three, six and 12 months
  • Group education patients were told to exclude sugar from their diet and lose weight. They attended five 90-minute sessions during the first six months.

Statistical Analysis

  • Student's unpaired T-test was used to compare normally distributed data (HbA1c) and the Mann Whitney U test for results that were not normally distributed (change in weight)
  • Chi-square tests were used to compare distributions and simple regression analysis to measure associations.
Data Collection Summary:

Timing of Measurements

Weight and HbA1c measured at the first clinic visit and at three, six and 12 months. Fasting blood glucose measured at one year.

Dependent Variables

  • Weight
  • HbA1c
  • Fasting blood glucose
  • General and dietary knowledge of diabetes assessed by multiple choice questionnaire.

Independent Variables

Patients were randomized to usual "unstructured" clinic care or to group education by diabetes specialist nurses and a dietitian.



Description of Actual Data Sample:
  • Initial N: 291 identified potential study participants. After application of exclusion criteria, 87 patients were found to be suitable and randomized.
  • Attrition (final N): 75 completed the study, 39 in the control group (16 males, 23 females) and 36 in the intervention group (20 males, 16 females)
  • Age: 56.5 years in the intervention group, 56.4 years in the control group
  • Anthropometrics: Groups had similar age, sex distribution, weight, BMI and HbA1c at entry but these were not statistically analyzed
  • Location: United Kingdom.
Summary of Results:



Intervention Group (N=36, Mean and 95% CI) Control Group (N=39, Mean and 95% CI) Mean Difference and 95% CI P-value
HbA1c: Initial (%) 12.3 (11.4 to 13.2) 12.7 (11.9 to 13.5)

0.4 (-0.86 to 1.52)

HbA1c: Three months (%)

8.6 (7.9 to 9.3)

9.7 (9.0 to 10.4)

1.1 (0.1 to 2.1)


HbA1c: Six months (%) 7.9 (7.0 to 8.1) 9.5 (8.7 to 10.4) 2.0 (0.9 to 3.0) <0.001
HbA1c: 12 months (%) 9.0 (8.2 to 9.8) 9.9 (8.9 to 10.9) 0.9 (-0.4 to 2.2) NS
Fasting blood glucose: 12 months (mmol per L) 9.1 (7.9 to 10.3) 10.3 (8.8 to 11.8) 1.2 (-0.7 to 3.1) NS

Questionnaire Score: 12 months (out of 36)

24.4 (23.3 to 25.5)

18.4 (17.1 to 19.7)

6.0 (2.5 to 8.7)


Other Findings

Six months after diagnosis, patients receiving group education had lost more weight [median 7kg (95% confidence interval 5.5 to nine) vs. 2kg (95% confidence interval one to five), P<0.002] and were better controlled [HbA1c median 7.5% (95% confidence interval 7.0 to 8.1) vs. 9.5% (95% confidence interval 8.7 to10.4), P<0.001] than those randomized to the usual clinic system.

At one year (after no further visits), the difference in weight loss was less [5.5kg (95% confidence interval 4.0 to 6.5) vs. 3kg (95% confidence interval two to four), P < 0.05)] and diabetic control was similar [HbA1c 9.0% (95% confidence interval 8.2 to 9.8) vs. 9.9% (95% confidence interval 8.9 to 10.9)].

At one year, only 14 (39%) of the education group and 9 (23%) of those attending the clinic had a fasting blood glucose less than 7.0mmol per L.  

The mean time each patient in the control group was exposed to potential education by either doctor or dietitian was 137 (131 to 143) minutes per year, so that the 39 control patients used 89 hours of professional time (51% doctor and 49% dietitian).

Patients attending the education sessions spent three times as long with members of staff (450 minutes a year) but because they were seen in groups, used only 30% more staff time (114 hours in the year, only 8% of which was provided by doctors at the initial visit).

Author Conclusion:

We have shown that six months after diagnosis, obese maturity onset diabetic patients lost more weight and had better blood glucose control when treated in groups than when receiving usual clinic care.

Funding Source:
Foundation associated with industry:
Reviewer Comments:

Measurements were not described. Groups were not statistically analyzed for differences at baseline.

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) No
  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? ???
  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? ???
  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? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  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)? N/A
  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? ???
  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