MNT: Disorders of Lipid Metabolism (2015)
- Age 20 to 79 years
- Type 2 diabetes
- HbA1c at least 6.5% (NGSP)
- Received treatment in medical clinics.
Volunteer general practitioners who agreed with the study purposes and procedures were recruited.
- Six-month cluster randomized controlled trial with randomization at the practice level and two intervention arms
- General practitioners representing a primary care clinic were randomly assigned to either the Intervention Group (IG) or Control Group (CG) with the use of a randomization list.
Patients were blinded to the assignment of education.
Intervention Group (IG)
- The IG received structured individual-based lifestyle education that focused on the reduction in energy intake at dinner and an increase in vegetable intake at breakfast and lunch
- The program was structured in four steps
- Basic information on glycemic control
- Actions for glycemic control
- Daily activities for glycemic control
- Management of stress for glycemic control.
- Support for self-management of glycemic control, including diet, exercise and stress management, was provided by trained registered dietitians in three or four sessions
- Sedentary participants were encouraged to increase basal physical activity.
Control Group (CG)The CG received general information and advice on dietary intake and glycemic control from registered dietitians.
- Intention-to-treat (ITT) analysis was conducted
- Last observation carried forward (LOCF) method and multiple imputation (MI) method were used for handling missing data. Per-protocol analysis with the complete data set was conducted as a sensitivity analysis.
- Mixed-effects linear models were used to exam the effects of the treatment and cluster effect:
- Model One: Crude model
- Model Two: Baseline-adjusted model
- Model Three: Baseline, gender, age and BMI-adjusted model
- Model Four: Multi-variate-adjusted model.
Timing of Measurements
Measurements of HbA1c, BMI, BP, lipid profile and dietary intake were made at baseline, at three months and at six months (end-point).
- Dietary intake, including energy, vegetable, dietary fiber, carbohydrate, protein and fat (assessed using the FFQW82, a food frequency questionnaire developed consisting of a list of 82 foods).
IG or CG.
- Medication use
- Physical activity.
193 (84 male, 109 female)
Attrition (Final N)
- 154 (84 in IG; 70 in CG)
- Overall dropout rate of 20% (20% for IG and 25% for CG).
61.3 years (60.4 years for IG and 62.3 years for CG).
- IG showed a significantly greater mean change in HbA1c from baseline compared with CG (-0.7% vs. -0.2%, -0.5% difference; P=0.004)
- A tendency toward improvement was observed for the other clinical outcome measures (BMI, FPG, systolic BP diastolic BP, LDL-cholesterol, HDL-cholesterol and TG), but the improvement was not statistically significant
- IG showed a significantly greater mean change in energy intake at dinner compared with the CG (-23kcal vs. -4kcal, -19 difference; P=0.031)
- IG showed a significantly greater mean change in vegetable intake for whole day compared with CG (35.1g vs. -0.2g, 35.3 difference; P=0.000), (LOCF, Model 1)
- IG showed a significantly greater mean change in vegetable intake for breakfast compared with CG (16.0g vs. -0.3g, 16.3 difference; P=0.001; LOCF, Model 1)
- IG showed a significantly greater mean change in vegetable intake for lunch compared with CG (13.1g vs. 0.5g, 9.5 difference; P=0.009; LOCF, Model 1).
|Government:||Ministry of Education, Culture, Sports, Science and Technology in Japan Grant-in-Aid for Scientific Research|
- Cluster randomization design eliminates the possibility of contamination bias between intervention and control participants in the same clinic
- Use of FFQW82 helped to facilitate problem-solving and goal-setting strategies
- Proportions of patients using insulin were similar in each group, which could eliminate a significant bias.
- Only patients were blinded to the assignment of education
- Enrollment of seven to 13 patients per clinic was permitted, despite protocol requirement of 10 patients.
- Diabetes medication of some patients may have been changed during study period, which would bring about a bias
- Success of program was to some degree dependent on skills of dietitians
- Earlier assessment could be biased as a result of changes made only because subjects were conscious of being studied.
Quality Criteria Checklist: Primary Research
|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|
|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?||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?||Yes|
|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?||Yes|
|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?||Yes|
|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)?||Yes|
|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?||Yes|
|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|