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DM: Blood Glucose Self-Monitoring (2007)

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

1. To obtain detailed information on glycemic control in a pediatric population

2. To identify particular factors influencing metabolic control during continuous subcutaneous insulin infusion (CSII) in pediatric patients

Inclusion Criteria:
Children and adolescents with  type 1 diabetes who wanted to change from multiple daily injection (MDI) therapy to insulin pump therapy
Exclusion Criteria:
None given.
Description of Study Protocol:

Recruitment

Children and adolescents from the diabetes clinic of the Charite Children's Hospital in Berlin were recruited between November 2001 and September 2003.

Design

Comparison of SMBG and HbA1c with information obtained from an ambulatory continuous glucose monitoring system (CGMS) before and six weeks after 50 children or adolescents with type 1 diabetes started CSII

Blinding used (if applicable): no

Intervention (if applicable)

Insulin pump treatment was started according to a three-step education approach (instruction in the mechanics of pump use; hospital admission (2 days) for CSII initiation and individual education; and intensive monitoring and contact with health professionals for 1 month.

Statistical Analysis

  • Wilcoxon test for differences of values before and 6 wks after CSII
  • Mann-Whitney U-test for continuous variables and chi-square test for categorical variables for differences between groups
  • Medtronic-Minimed Software version 3.0A for downloading and analyzing CGMS data
Data Collection Summary:

Timing of Measurements:

Three days of CGMS done before therapy change to CSII, and again 6-8 weeks after

 Dependent Variables

  • CGMS information (Medtronic MiniMed Inc, Northridge, CA; and Medtronic-Minimed software version 3.0A).  Data from 2 complete days if 288 sensor values/24 h available; otherwise only data from first complete day.
    • Average glucose concentration/24 h
    • average glucose concentration during day (0800 - 2200 hrs)
    • average glucose concentration during the night (2200- 0800 hrs)
    • number of excursions, time, and area under glucose curve above 180 mg/dl or below 60 mg/dl
  • SMBG average glucose concentration per 24 hrs (Medisense Precision Xtra blood glucose meter (Abbott, IL)
  • HbA1c (DCA 2000 Analyzer, Bayer Diagnostics, Germany

Independent Variables

  •  duration of diabetes

Control Variables

 none

Description of Actual Data Sample:

Initial N: 50 children and adolescents with type 1 diabetes (21 boys, 29 girls)

Attrition (final N): none reported

Age: median age 12.6 yrs (range: 1.3-16.4 yrs)

Ethnicity: not reported

Other relevant demographics: none reported

Anthropometrics: BMI 19.8±3.1 kg/m2

Location: Clinic of General Pediatrics, Humboldt-University, Berlin, Germany

 

Summary of Results:

 

Variables

Before CSII

n=50

mean±SD or range

With CSII (at 6 wks)

n=50

mean±SD or range

Significance between groups
HbA1c 8.1±3.1 7.7±0.9 p=0.001
Insulin/kg (IU/kg)

0.93±0.29

0.82±0.24

p=0.002

SMBG glucose, 24 h average (mg/dl)

171 (78-283)

148 (86-308)

p=0.026
CGMS glucose, 24 h average (mg/dl) 179 (83-351) 145 (88-309 p=0.002

Other Findings

1.  Decrease in 24 hr glucose corresponded with a decrease in hyperglycemia, particularly during the day.  No significant decrease in glucose average during the night

2.  No significant change occurred in the number of hyperglycemic excursions as well as the frequency of hypoglycemic events before and after the start of CSII.

Author Conclusion:

CGMS should be used when capillary blood glucose monitoring is of limited value (e.g.: in patients with high variability of glucose values) or for assessment of glycemic control at night to optimize therapy and metabolic control in patients with CSII.

Funding Source:
Reviewer Comments:
No discussion of how food was assessed during the CSII period
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? 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? No
  2.2. Were criteria applied equally to all study groups? N/A
  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? Yes
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  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? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  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? ???
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? ???
  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? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? No
  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? N/A
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)? No
  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