GDM: Monitoring (2008)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To examine the effects of self-monitoring of blood glucose on feelings of self-efficacy, dietary compliance, and pregnancy outcomes in women with diet-controlled gestational diabetes mellitus.
Inclusion Criteria:
  • Gestational diabetes mellitus < 33 weeks gestation
  • Fasting blood glucose < 95 mg/dl on oral glucose tolerance test
Exclusion Criteria:
None specifically mentioned.
Description of Study Protocol:

Recruitment

Subjects were followed in the Diabetes-in-Pregnancy Program at Temple University Hospital and/or 1 of its satellite hospitals.

Design:  Randomized Controlled Trial.  Methods of randomization not described.

Blinding used (if applicable):  Not possible 

Intervention (if applicable)

  • Experimental group:  measured blood glucose levels 4 times daily using reflectance meter with memory (One Touch Profile) for a total of 4 times a week
  • Control group:  metabolic status assessed by periodic monitoring at prenatal visits
  • For both groups blood glucose levels were measured at fasting and 1 hour after meals
  • Antepartum care was provided by a team of specialists and was identical except for glucose surveillance
  • Individualized teaching/counseling regarding gestational diabetes and its management was provided to all study participants by the diabetes educator
  • All patients treated to attain same metabolic goals:  fasting blood glucose level < 95 mg/dl and 1-hour postprandial glucose level < 120 mg/dl

Statistical Analysis

Data were analyzed using intent-to-treat principle.  Student t tests were used to compare the means of continuous variables.  Comparisons between categorical variables were performed using chi-square analysis.

Data Collection Summary:

Timing of Measurements

Feelings of self-efficacy measured at study entry and at 37 weeks gestation.  Dietary compliance assessed at each visit.

Dependent Variables

  • Feelings of self-efficacy measured using Diabetes Empowerment Scale, reliability of 0.94
  • Emotional adjustment to diabetes assessed using modification of Appraisal of Diabetes Scale, reliability of 0.73
  • Knowledge of gestational diabetes assessed using Diabetes-in-Pregnancy Knowledge Screen, with demonstrated internal consistency and reliability of 0.76
  • Dietary compliance assessed using diet portion of Diabetes Compliance Questionnaire, based on self-report 

Independent Variables

  • Experimental or control group assignment
  • Compliance with SMBG and diet monitored at each prenatal visit 

Control Variables

 

Description of Actual Data Sample:

Initial N: 64 eligible for inclusion.  61 randomized, 31 to SMBG and 30 to periodic monitoring.

Attrition (final N):  58 women, 3 in periodic monitoring were lost to follow-up.

Age:  SMBG group mean age 30.3 ± 5.4 years, periodic monitoring mean age 29.0 ± 6.4 years

Ethnicity:  SMBG group:  6.5% Hispanic, 3.5% Black, 51.6% White, 6.5% Other; periodic monitoring group:  14.8% Hispanic, 29.6% Black, 51.9% White, 3.7% Other

Other relevant demographics:

Anthropometrics:  There were no significant differences between groups at baseline

Location: Pennsylvania

 

Summary of Results:

Other Findings

Women in both groups achieved similar pretest scores on the Diabetes-in-Pregnancy Knowledge screen, the Diabetes Empowerment Scale, and the Appraisal of Diabetes Scale.

Both groups of women achieved excellent glucose control, only 1 woman in each group required insulin therapy.

There were no significant differences with regard to feelings of self-efficacy, emotional adjustment to diabetes, dietary compliance, birth weight, gestational age at delivery, Apgar scores, and neonatal complications.

Rates of macrosomia, delivery by Cesarean section, and occurrence of birth trauma were similar. 

Author Conclusion:
SMBG appears to have little effect on maternal feelings of self-efficacy, dietary compliance, or pregnancy outcomes in women with diet-controlled GDM.
Funding Source:
Reviewer Comments:
Authors note that type II error cannot be excluded due to small sample size.  Authors note that similar rates may be due to the fact that both groups received intensive education and support.
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? Yes
  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? 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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  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? 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? 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? 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? ???
  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)? N/A
  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? No
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