DM: Blood Glucose Self-Monitoring (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To determine if therapeutic management programs that include self-monitoring of blood glucose (SMBG) result in greater A1C reduction in non-insulin requiring type 2 diabetes patients compared to programs without SMBG.
Inclusion Criteria:
  • Randomized controlled trials
  • Trial compared a diabetes management strategy with and without SMBG
  • Adult patients 18 years and older
  • Type 2 diabetes
  • Non-insulin use
  • Trial must have data of A1C from baseline and post-intervention
  • Trials reported in English, or translated to English

 

Exclusion Criteria:
  • Studies with populations of type 1 diabetes
  • Gestational diabetes studies
  • Maturity-onset diabetes in the young (MODY) studies
  • Studies who enrolled pregnant subjects
  • Studies who enrolled those injecting insulin
  • Studies who enrolled those taking troglitazone
  • Studies who enrolled those taking any other experimental medication
Description of Study Protocol:

Recruitment

  • Data base searches done using various data bases including MEDLINE (1966-2004).
  • Potential studies to be included in the meta-analysis were reviewed for quality based on specific criteria.
  • Data was extracted from the selected studies
  • Quality of the articles assessed using modified version of criteria specified by Cochrane Collaboration

Design

  •  Meta-analysis

Blinding used (if applicable)

  •  Not applicable

Intervention (if applicable)

  • Not applicable

 Statistical Analysis

  • The measure of effect of SMBG was defined as the difference in the reduction from baseline to post-intervention, of mean A1C levels between SMBG and non-SMBG groups.
  • The summary measure of effect and its 95% confidence interval were computed under fixed and random effects models.
  • Chi-square test for heterogeneity was performed.

 

Data Collection Summary:

Timing of Measurements

  •  Baseline and post-intervention.   Duration of studies varied from 12 weeks to 44 weeks.

Dependent Variables

  • A1C

Independent Variables

  • SMBG
  • Non-SMBG

Control Variables

  • Not identified

 

Description of Actual Data Sample:

Initial N: 680 studies found with the database search; 296 were identified as possible sources of relevant information

Attrition (final N): 8 studies met the inclusion/exclusion criteria to be used in this meta-analysis, representing 1307 subjects

Age:  see below

Ethnicity:  not mentioned

Other relevant demographics:  see below

Anthropometrics:

Location: Not discussed

Descriptive data of trials
Studies in Meta-analysis Age in years Duration of diabetes

Fontbonne et al, 1989

  • Intervention group
  • Control group

 

54.5 ± 10.7

56.3 ± 9.1

 

12.2 ± 6.6 years

12.7 ± 0.8 years

Estey et al, 1990

  • Intervention group
  • Control group
 

56.2 ± 11.1

54.2 ± 13.3

 

not provided

not provided

Muchmore et al, 1994

  • Intervention group
  • Control group
 

57.3 ± 2.3

60.1 ± 2.2

 

5.7 ± 1.4 years

5.2 ± 1.4 years

Jaber et al, 1996

  • Intervention group
  • Control group
 

59 ± 12

65 ± 12

 

6.8 ± 6.5 years

6.2 ± 4.8 years

Schwedes et al, 2002

  • Intervention group
  • Control group

 

58.7 ± 7.6

60.5 ± 6.6

 

5.46 ± 4.77 years

5.22 ± 3.94 years

Guerci et al, 2003

  • Intervention group
  • Control group
 

60.9 ± 9.4

62.2 ± 9.1

 

92.3 ± 75.0 months

100.8 ± 76.6 months

Davidson et al, 2004

  • Intervention group
  • Control group
 

49.8 ± 11.2

50.9 ± 11.0

 

5.5 ± 4.7 years

5.8 ± 5.8 years

Kwon et al, 2004

  • Intervention group
  • Control group
 

53.88 ± 9.53

54.78 ± 9.96

 

5.58 ± 4.85 years

5.51± 4.83 years

 

Summary of Results:

 

Post-Intervention A1C changes
Studies in Meta-analysis Difference in reduction between groups (SMBG reduction minus non-SMBG group)

Fontbonne et al, 1989

0.140

Estey et al, 1990

-0.400

Muchmore et al, 1994

-0.690

Jaber et al, 1996

-1.551 (p<0.05)

Schwedes et al, 2002

-0.460 (p<0.05)

Guerci et al, 2003

-0.280 (p<0.05)

Davidson et al, 2004

-0.230

Kwon et al, 2004

-0.840 (p<0.05)

Other Findings

SMBG as a part of a multi-component management strategy produced an A1C reduction of -0.39% (95% CI: -0.54%, -0.23%) under the fixed effects model, and -0.42% (95% CI: -0.63%, -0.21%) under the random effects model, when compared to therapies that did not include SMBG.

Heterogeneity among studies was not statistically significant.

Mean testing frequency of the 8 studies included in this meta-analysis was about 5-7 times per week.

 

Author Conclusion:
Mulit-component diabetes management programs with self-monitoring blood glucose result in better glycemic control among non-insulin-using type 2 diabetes patients.
Funding Source:
Reviewer Comments:
Included in the paper is a good discussion of effects of possible bias through sensitivity analyses.  Results still favored SMBG testing after this analysis.
Quality Criteria Checklist: Review Articles
Relevance Questions
  1. Will the answer if true, have a direct bearing on the health of patients? Yes
  2. Is the outcome or topic something that patients/clients/population groups would care about? Yes
  3. Is the problem addressed in the review one that is relevant to dietetics practice? Yes
  4. Will the information, if true, require a change in practice? No
 
Validity Questions
  1. Was the question for the review clearly focused and appropriate? Yes
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? Yes
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? Yes
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? Yes
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? Yes
  6. Was the outcome of interest clearly indicated? Were other potential harms and benefits considered? Yes
  7. Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described? Yes
  8. Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included? Yes
  9. Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed? Yes
  10. Was bias due to the review's funding or sponsorship unlikely? Yes