EAL

DM: MNT (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To evaluate the effectiveness of a new program to improve control of patients with diabetes cared for in the primary care setting, without the program assuming long-term management of these patients. This study analyzes the initial "pulse" of intensive outpatient care, followed by subsequent surveillance to determine long-term benefits of this pulse.

Inclusion Criteria:

Unselected consecutive adult patients with diabetes mellitus referred by their primary care physicians with the expectation that they would benefit from patient-empowerment skills provided by diabetes educators.
Patients with unsatisfactory glycemic control, frequent hypoglycemia, or inadequate self-management
Signed an agreement that they would participate in the program for the next 12 weeks.

Exclusion Criteria:

not specified.

Description of Study Protocol:

Recruitment -568 consecutive unselected adult patients with diabetes mellitus referred by their primary care physician (PCP). 260 of these were referred from PCPs in the medical center's department of internal medicine, and 308 were referred by community PCPs.

Design - Before-After Study

Blinding used (if applicable) not applicable

Intervention (if applicable):

12-week intensive program, consisting of instruction and support in diabetes self-management coupled with adjustment of insulin and oral hypoglycemic agents, was provided by diabetes educators and supervised by endocrinologists. Each patient had an initial hour clinic visit with both a nurse diabetes educator and a dietitian. Subsequent clinic visits were scheduled according to patient need. Weekly contact was made, consisting of either a clinic visit, a telephone call, an exchange of email or faxed message, regarding home blood glucose results. Protocols for oral and insulin medication were developed and supervised by the endocrinologist. The main outcome variable was HbA1c, using the difference between entry and value obtained at 3 months. By mutual agreement, an additional 12 weeks was added for some patients to achieve better control.

Statistical Analysis To determine which variables were associated with improvement in HbA1c, univariate analysis was done, using the following independent variables: patient characteristics at entry (race, age, body mass index (BMI)), program-related variables (changes in weight or exercise, adherence with instructions for home blood glucose monitoring, starting insulin or insulin pump), and provider-related variables (number of visits and total contacts with educators).

Two-sample t-tests were used, as well as Pearson's product moment correlation in the univariate analysis, with a Sidak correction method to adjust for the "multiple comparison fallacy".

Independent variables identified with an association at the P<.25 level in the univariate analysis were included in the multiple regression analysis.

Data Collection Summary:

Timing of Measurements - for outcome, HbA1c at entry and at 3 months. Home blood glucose was monitored frequently on an individualized basis.

Dependent Variables

HbA1c

Independent Variables

patient characteristics at entry (race, age, body mass index (BMI))
program-related variables (changes in weight or exercise, adherence with instructions for home blood glucose monitoring, starting insulin or insulin pump)
provider-related variables (number of visits and total contacts with educators)

Control Variables not specified

Description of Actual Data Sample:

Initial N: 568 started. 350 who finished are subjects of this report.

Attrition (final N): 350. (107 dropped out before completing program; 111 are not yet finished and not included in this report.) Most frequent reason for dropping out was financial or health insurance barrier in payment.

Age: overall, Mean age was 51.0 (SD 15.2)

Ethnicity: overall, 68.9 % white, 14.9% African American, 14.4% other or unknown.

Other relevant demographics: Overall, 55% women; diabetes duration Mean 10.3 years (SD 10.0); HbA1c at entry Mean 9.4 (SD 1.9). Individuals with type 1 diabetes (n=70); individuals with type 2 taking insulin at start (n=70); individuals with type 2 with no previous insulin (n=105).

Anthropometrics BMI at entry overall Mean 31.7 (SD 8.8); 48.0% self-report no exercise.

Location: Nashville (Vanderbilt Medical Center).

Summary of Results:

Table: Predicting change in HbA1c by multiple regression analysis

Variables	Coefficient	95% CI	P Value
HbA1c, value at start	0.66	0.57 to 0.75	.000
Type of diabetes	0.38	0.10 to 0.66	.001
Sex	-0.49	-0.83 yo -0.15	.005
Duration of diabetes	-0.02	-0.04 to -0.01	.018
Change in exercise	0.001	0.00 to 0.00	.26
Hypoglycemia at start	0.14	-0.34 to 0.63	.56
Race	-0.08	-0.45 to 0.29	.66
Constant	-4.98

Other Findings

Overall, there was a mean decrease in HbA1c of 1.7% (95% CI, 1.4% - 1.9%). Individuals with type 1 diabetes had the least amount of HbA1c change (1.1%). Individuals with type 2 diabetes taking insulin at start had a decrease of 1.4% (95% CI, 1.0% - 1.7%). Individuals with type 2 diabetes who were not taking insulin at start had greatest decrease in HbA1c, a mean of 2.3% (95% CI, 1.9% - 2.7%)

The mean number of nurse-educator clinic visits was 3.8 (SD 1.7) and the mean number of dietitian clinic visits was 5.5 (SD 2.3). mean number of total contacts (including phone, email or fax) with educators was 9.0 (SD 4.6), over an average duration of 14.6 weeks in the program.

Author Conclusion:

This model emphasizes that mutally accepted guidelines should outline the interaction between providers for optimal management of the population. It shows the 3-month intensive outpatient counseling and treatment resulted in important improvement in HbA1c levels, across the entire clinical spectrum of diabetes including type 1 and type 2 with or without insulin therapy. The magnitude of the observed initial fall in HbA1c was similar to that observed during the first 6 months of the DCCT intensive treatment cohort.

Funding Source:

Reviewer Comments:

Good discussion of limitations and predictors of improvement in HbA1c. Authors note that sampling consisted of consecutively referred patients and may not be representative of the population.

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?		???
	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?	???
	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?	???
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?		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?	N/A
5.	Was blinding used to prevent introduction of bias?		N/A
	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.)	N/A
	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?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	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?	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)?	N/A
	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?	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