MNT: RDN in Medical Team (2015)


Trento M, Basile M, Borgo E, Grassi G, Scuntero P, Trinetta A, Cavallo F, Porta M. A randomised controlled clinical trial of nurse-, dietitian- and pedagogist-led Group Care for the management of Type 2 diabetes. J Endocrinol Invest. 2008; 31 (11): 1,038-1,042.

PubMed ID: 19169063
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 verify if group care, a model to manage type 2 diabetes (T2DM) by systemic continuing group education, can be administered by trained nurses and dietitians under pedagogic guidance and improve metabolic control, quality of life, locus of control and insulin resistance.

Inclusion Criteria:
  • Non-insulin-treated T2DM
  • No exposure to group care prior to study
  • Informed consent.
Exclusion Criteria:
  • Insulin-treated T2DM
  • Previous experience with group care.
Description of Study Protocol:

Randomized controlled clinical trial. Forty-nine patients with non-insulin-treated T2DM were randomized (using random number tables) to the treatment group (group care) and the control group (individual diabetes care).

Blinding Use

Not described, probably not possible due to study design, implied with measurements.


Group care was conducted by six trained nurses and one dietitian who received training by an accredited program, a detailed operating manual and pedagogical supervision throughout the study. Group education sessions were held every three to four months, lasted 40 minutes to 50 minutes and followed by brief individual consultations with the physician. The control group received habitual individual care and education delivered by the same operators involved in group care. Follow-up was for two years and included measurements of biochemical and clinical variables, health behaviors, quality of life, state and trait anxiety and locus of control.

Statistical Analysis

  • Descriptive data are shown as absolute frequencies of the different modalities for categorical data and as mean±SD for continuous variables
  • Differences between cases and controls at baseline were assessed by using chi-square for categorical variables and T-test for continuous variables
  • Differences between values at baseline and year two were tested with a T-test for dependent data. P<0.05 was required to declare a significant difference between pre-values and post-values
  • Differences between cases and controls following intervention were assessed by fitting a multivariate model where, for each behavioral and clinical variable, the difference between baseline and year two values represented the dependent variable and treatment group (cases vs. controls), sex, age, duration of diabetes and baseline value of the dependent variable were taken as as independent variables.
Data Collection Summary:

Timing of Measurements

  • Body weight, fasting blood sugar, glycated hemoglobin (HbA1c) and blood pressure were measured every three months
  • Yearly screening for complications included assays of serum creatinine, triglyceride, total cholesterol and HDL-cholesterol
  • Serum insulin was measured at baseline and after two years.

Dependent Variables

  • Biochemical and clinical variables:
    • Fasting blood glucose
    • HbA1c
    • Body mass index (BMI)
    • Waist circumference
    • Lipids
    • Creatinine
    • Blood pressure
    • Serum insulin (measured while patients were on their usual medication by immunoradiometric assay, intra-assay and inter-assay coefficients of variation 3.5% and 4.2%, respectively)
    • Homeostasis model assessment index of insulin resistance (HOMA-IR) [calculated according to the formula: HOMA = Glycemia (mmol per L) x Insulinemia (ng per ml)/22.5].
  • Health behaviors (using a questionnaire)
  • Quality of life (using a modified version of the Diabetes Quality of Life (DQOL) questionnaire; higher total scores indicated worse quality of life)
  • State and trait anxiety [using the State-Trait Anxiety Inventory (STAI)-1 and (STAI)-2]
  • Locus of control (using the Peyrot and Rubin tool).

Independent Variables

  • Group care treatment
  • Individual diabetes care (control group).

Control Variables

  • Sex
  • Age
  • Duration of diabetes
  • Use of hypoglycemic and anti-hypertensive medications.
Description of Actual Data Sample:

Initial N

N=49 randomized

  • Treatment: N=25 (13 males, 12 females)
  • Control: N=24 (16 males, eight females).

Attrition (Final N)

N=45. Four patients (one in Group Care and three controls), dropped out of the study. The patient on Group Care and one control had moved to another city, whereas the other two controls were lost to follow-up.


  • Treatment group: Aged 64.6±9.3 years
  • Control group: Aged 68.1±7.1 years.

Other Relevant Demographics

Patients and controls were similar by schooling, occupation, family and duration of diabetes:

  Group Care Controls Significance
Schooling (N/P/M/H/U) 15/4/3/2/1 13/7/3/1/0 NS
Occupation (H/R/W) 1/22/2 0/24/0 NS
Known duration of diabetes (years) 11.0±7.3 14.8±7.7 NS
Attendance in clinic before study (years) 9.7±5.4 12.8±6.6 NS
Family history of DM (0/1) 12/13 10/14 NS
Smoking (currently/never/stopped) 14/1/10 12/3/9 NS

N: No formal education; P: Primary school; M: Middle school; H: High school; U: University degree; H: Housewife; R: Retired; W: White collar worker.


  Group Care Controls
BMI (kg/m2) 26.9±4.7 27.1±4.8
Waist circumference (cm) 99.5±12.7 100.0±11.7


Turin, Italy.


Summary of Results:

Key Findings

At the end of study, the patients on group care had lower HbA1c, insulin, HOMA-IR, fatalistic attitude and better quality of life than controls.

  Group Care Controls

Difference Between Group Care and Controls*


(N=25, mean±SD)

Two years
(N=24, mean±SD)

Mean Difference

(N=24, mean±SD)

Two years(N=21, mean±SD)

Mean Difference

HbA1c (percentage of total Hb) 8.0±1.3 7.6±0.8 -0.4±0.25 8.0±1.1 8.4±1.3 0.39±0.25 P<0.05
Serum insulin (ng per ml) 25.6±7.1 18.0±9.6 -7.7±7.4 17.7±8.3 24.3±13.7


HOMA 11.0±3.8 6.9±5.4


7.3±5.1 9.2±6.6 2.2±1.1 P<0.05
Quality of life (DQOL/Mod score) 69.8±10.9 65.0±11.0 -4.9±2.5 75.2±18.9 78.4±19.6 4.1±2.2


Locus chance 26.0±9.1 17.2±5.9


21.6±7.9 24.9±4.2 2.7±1.6


*The difference is adjusted by sex, age, duration of diabetes and baseline value of the dependent variable. 

Other Findings

No differences between the intensities of hypoglycemic and anti-hypertensive medications at the beginning and end of study in the two groups.
Author Conclusion:
  • Managing T2DM by a continuous structured group education program produces better results than the traditional one-to-one approach, both in clinical and psychological terms
  • This study may offer a model for health operators to re-organize clinical practice, if necessary by redistributing roles and responsibilities among the different members of the healthcare team to achieve better clinical outcomes, and for patients to improve lifestyle and strengthen the therapeutic alliance with health professionals.
Funding Source:
University/Hospital: University of Turin, Turin, Italy
Reviewer Comments:
  • No detailed inclusion or exclusion criteria and recruitment process described
  • Primarily retired, below-college education population in this study
  • Unclear if subject compliance (e.g., attendance to group or individual care) measured.
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? ???
  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? 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? No
  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? Yes
  6.6. Were extra or unplanned treatments described? No
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  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