NC: Diabetes Management (2007)

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

The purpose of the study was to evaluate the relative effectiveness of several diabetes education programs that teach self-care elements for NIDDM patients who have not previously undergone diabetes education.

Inclusion Criteria:
  • Patients with NIDDM who had been diagnosed for less than five years
  • Able to speak, read and understand English
  • Less than 80 years of age 
  • Received no previous formal instruction in diabetes care
  • Not taking over 75% of the maximum dose of oral hypoglycemic agents
  • No terminal illness.
Exclusion Criteria:

    Patients with insulin-dependent diabetes.

Description of Study Protocol:

Recruitment

NIDDM patients referred to a Diabetes Education Service in New South Wales, Australia, who had a screening interview.

Design

  • Patients were allocated randomly into one of four programs on diabetes education
  • Usual clinic care continued during the study and for some patients this included visits with a diabetes specialist which was not controlled for.

Blinding Used

None.

Intervention

  • Minimal program:
    • Two one-hour sessions (one taught by a nurse, one by an RD) conducted within two weeks of referral
    • Sessions covered the same materials as other programs, but in less detail
  • Individual education program:
    • Two sessions conducted within two weeks of referral, then sessions scheduled monthly until 12 months from the initial visit
    • The two initial sessions were with a nurse and RD for one hour and subsequent sessions with the nurse for 30 minutes
  • Group education program:
    • This consisted of two individual sessions and a three-day small group education
    • Individual monthly sessions were continued until a course could be scheduled
    • Two-hour group follow-ups were scheduled at three and nine months after the course
  • Behavioral program:
    • This consisted of a series of individual visits from a nurse; three were within the first month, after which session frequency was dependent upon the patient's needs
    • The minimal schedule was visits after three, six and 12 months, supplemented with random phone calls from the educator
    • After the initial visit, the sessions were conducted in the home
    • This program was based on cognitive-behavior strategies and emphasized cardiovascular risks
    • In the initial session, patients were given a risk factor appraisal, their beliefs regarding the importance of reducing risk factors through lifestyle change was provided
    • Therapy was provided on the three main topics of eating, exercise and smoking
    • The dietary approach was using pre-planned menus rather than portion control
    • Contracting was established using behavioral goals rather than outcomes for weight loss.

Statistical Analysis

Chi-Square Analysis and T-test. 

Data Collection Summary:

Timing of Measurements
 

Baseline, three months, six months and 12 months.

 Dependent Variables

  • HbA1c: Assessed by using high liquid chromatography
  • Diabetic Treatment: Type of medication and dosage
  • BMI: Weight and height were measured for calculation
  • Blood lipids: Total Cholesterol, HDL and cholesterol risk ratio were assessed
  • Blood pressure: Systolic BP and diastolic BP were assessed 
  • Smoking: A single report was used
  • Diabetes Knowledge: This was assessed using the 15-item diabetes knowledge scale.

 Independent Variables 

  • Minimal program
  • Individual education program
  • Group education program
  • Behavioral program. 
Description of Actual Data Sample:
  • Initial N: 238 total
    • Minimal program (37 female, 22 male)
    • Group education (31 female, 35 male)
    • Individual education (24 female, 33 male)
    • Behavioral program (32 female, 24 male)
  • Attrition (final N):
    • Minimal program (59) 100%
    • Group education (38) 42% attrition at 12 months
    • Individual education (34) 40% attrition at 12 months
    • Behavioral program (51) 9% attrition
  • Age:
    • Minimal program: 58 years
    • Group education program: 58 years
    • Individual education: 57 years
    • Behavioral: 61 years
  • Ethnicity: Australian
  • Other relevant demographics: Not stated
  • Anthropometrics groups: Similar
  • Location: New South Wales, Australia.

 

Summary of Results:

 

Variables

Minimal Education Group

Base to Six Months

Group Education Group

Base to One Year

Individual Education Group

Base to One Year

Behavioral Group

Base to One Year

Statistical Significance of Group Difference

HbA1c

 -2.2 change

 -3.0 change

-3.3 change -4.8 change

None

BMI

-1.4 change

-1.4

-2.0 -2.6

None

Total Cholesterol

0.12

0.16

0.12 -0.33

None

Other Findings

  • At three months, patients in the Behavioral Program had significantly greater reductions in cholesterol risk ratio and were more likely to visit a podiatrist than those in the other program. Both behavioral and group education patients had greater improvements in knowledge scores than the minimal patients. Behavioral patients also improved more than Individual education patients. At 12 months, behavioral patients had greater reductions in diastolic blood pressure than those in the other two programs.
  • Excessively high attrition rates in the individual education group (40%) and group education (42%) vs. only 9% in the behavioral group is significant and may in part explain the lack of significant findings
  • There were no significant differences between the programs in the amount of change produced in the following variables over any of the time periods: HbA1c, BMI, total cholesterol, HDL or systolic blood pressure.
Author Conclusion:
  • The authors concluded that more intensive programs based on patient time and resources may not necessarily produce greater outcome improvements than less intensive programs. Because the minimal program had a shorter duration, there also needs to be a further study on the impact of minimal programs over longer durations.
  • One of the other limitations mentioned was that possibly the doctors and diabetes educators who knew their patients had been allocated to the minimal program were more cautious in prescribing behavior education for these patients
  • This study also supported previous reports that differences in knowledge change between programs may not be as important as other outcomes. 
Funding Source:
Government: NIH, MRC
Reviewer Comments:
  • The study was very complex because of the different education visits, length of duration and comparison of outcomes
  • The attrition rate was very high in the individual (40%) and group education (42%)
  • Length of program, the frequency of contacts and presentation form are important variables that need to be considered. This also impacted the results.
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? ???
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? ???
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? ???
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? ???
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
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? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  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")? ???
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? No
  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%.) No
  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? ???
5. Was blinding used to prevent introduction of bias? No
  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.) No
  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? ???
  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? No
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  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? ???
  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? No
  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? ???
  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)? ???
  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? ???
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? N/A
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? ???