EAL

DM: Blood Glucose Self-Monitoring (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate the effect of meal-related self-monitoring of blood glucose (SMBG) on diabetes control in non-insulin-treated type 2 diabetic patients.
To investigate the burden of diabetes by measuring well-being and treatment satisfaction.

Inclusion Criteria:

Type 2 diabetes
Non-insulin treated
Body Mass Index (BMI) > 25 kg/m²
A1C between 7.5 and 10%
Diet-treated alone or in combination with sulfonylureas or metformin
Age 45-70 years
Duration of diabetes at least 3 months
Participation in diabetes education program within the previous 2 years

Exclusion Criteria:

Incapable of maintaining an eating diary and documenting their state of well-being
Sensomotor disturbances that might impair unassisted SMBG
Regular SMBG during the previous 6 months
Participated in another clinical trial within 30 days before start of the study
Pregnant or lactating females
Females without safe contraception method
Use of insulin, glucocorticoids, amphetamines, anabolic agents
Diet reduction during course of the study (<1,000 kcal/day)
Serum creatinine > 3 mg/dl
Serum transaminases > 50 units/liter
Serious underlying medical or psychiatric condition
Drug or alcohol abuse

Description of Study Protocol:

Recruitment

21 centers in Germany and Austria
Outpatient settings of family practice and hospitals

Design

Prospective, randomized, controlled, multicenter parallel group comparison
- Random assignment to either SMBG group or control group
- Six months of intervention and six months of follow-up

Blinding used (if applicable)

Not used

Intervention (if applicable)

The SMBG group instructed to test home glucose 6 times per day, 2 days per week. They were to document glucose results, eating habits and state of well-being. Subjects were counseled every 4 weeks with focus on self-perception, self-reflection, and self-regulation based on a particular algorithm.
The control group received non-standardized counseling on their diet and lifestyle.

Statistical Analysis

Data analysis done using SAS program version 6.12.
Primary efficacy parameter analysis done with ANCOVA for the endpoint with baseline as covariate and SMBG as the main effect.
Secondary efficacy parameters analyzed in an exploratory manner.
Psychosocial aspects evaluated by Psychonomics (Cologne, Germany).

Data Collection Summary:

Timing of Measurements

Laboratory assessments (A1C, cholesterol, microalbumin) and body weight measured at randomization, 8, 16, and 24 weeks.
Questionaires completed at randomization and 24 weeks.
Twice during the 6 month follow-up A1C, body weight, and questionaires were done.

Dependent Variables

Primary endpoint: Change in A1C
Secondary endpoints: Change in body weight, lipids, microalbumin, and changes in well-being and treatment satisfaction

Independent Variables

SMBG

Control Variables

Not discussed

Description of Actual Data Sample:

Initial N: 250 randomized (48% women)

Attrition (final N): 223 (n=113 in SMBG group) were included in the per-protocol analysis. These subjects met protocol criteria, completed the study, showed valid efficacy parameters measurements, and were =/> 70% compliant.

Age in years: 58.7 ± 7.6 (SMBG group) and 60.5 ± 6.6 (control group)

Ethnicity: not mentioned

Other relevant demographics: No significant difference in baseline A1C: 8.47 ± 0.86 % in SMBG group and 8.35 ± 0.75 % in control group. No significant difference between groups in baseline total cholesterol, triglycerides, microalbumin, body weight, treatment satisfaction scores and general well-being scores.

Anthropometrics: Body mass index (kg/m²) 31.0 ± 4.6 (SMBG group) and 31.9 ± 5.5 (control group)

Location: Germany and Austria

Summary of Results:

**Results at study end**
	SMBG Group	Control group	Statistical Significance of Group Difference
A1C change (%)	-1.0 ± 1.08	-0.54 ± 1.41	P = 0.0086
Body weight change (kg)	-1.96 ± 2.99	-1.62 ± 3.54	P = 0.332
Total cholesterol change (mg/dl)	-3.46 ± 27.84	+0.2 ± 29.37	P = 0.146
Triglycerides change (mg/dl)	-7.1 ± 139.97	-19.87 ± 107.01	P = 0.965
Microalbumin change (mg/l)	-4.55 ± 41.67	+ 2.76 ± 46.32	P = 0.123

Other Findings

Treatment satisfaction increased similarly in both groups (P = 0.9).
Well-being was improved in the SMBG group (P = 0.053).
SMBG group tested on average of 24.8 ± 3.9 times per week.
97.9 % of the subjects in the SMBG group completed the glucose/eating diary.
Within the SMBG group, three treatment response groups were identified: those that showed continuous success, those that showed delayed success, and those that showed failure.

Author Conclusion:

Meal-related self-monitoring of blood glucose within a structured counseling program improved glycemic control in the majority of non-insulin-treated type 2 diabetic patients in this study.

Funding Source:

Reviewer Comments:

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)	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")?	N/A
4.	Was method of handling withdrawals described?		No
	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%.)	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?	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?	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?	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?	No
	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?	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?		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)?	No
	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?	No
	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?		No
	9.1.	Is there a discussion of findings?	No
	9.2.	Are biases and study limitations identified and discussed?	No
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