EAL

HD: Effectiveness of Nutrition Intervention Methods (2010)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine the clinical outcomes and costs of Project Dulce, a combined stepped-care diabetes nurse case management program and culturally oriented peer-led self-empowerment training program.

Inclusion Criteria:

Diagnosis of diabetes
SD-CMS beneficiary enrolled in Project Dulce during the intervention period
Availability of lab results for HgbA1c at enrollment and one year after enrollment of six months or more.

Exclusion Criteria:

Those not enrolled in the Project Dulce program as a SD-CMS beneficiary
No diagnosis of diabetes.

Description of Study Protocol:

Recruitment

Participants were referred by their physicians, participated in Project Dulce and remained enrolled in SD-CMS for one year between July 2000 and December 2002.

Design

A cohort study with historical controls.

Intervention

Patients had an initial (50-minute) visit with a nurse and were asked to return for follow-up visits with the nurse (25 or 50 minutes) and dietitian (25 minutes). Participants were asked to participate in a group self-management training program. The program consisted of an eight-week curriculum delivered by trained peer educators. Classes were taught in the patients' native language and covered diabetes and its complications; the role of diet, exercise and medication; and the importance of self-monitoring.

Statistical Analysis

The T-tests or X² tests were used to compare demographic and clinical characteristics between Project Dulce participants and control patients. Linear regression was used to estimate changes in clinical outcomes associated with participation in Project Dulce,controlling for age, gender and baseline values, where observations were weighted by length of enrollment to account for heteroscedasticity. Total costs were substantially skewed and kurtotic and, for inpatient expenditures, there was a large proportion of non-users. The a priori level of significance was 0.05.

Data Collection Summary:

Timing of Measurements

Data on blood pressure and cholesterol were collected when available.

Dependent Variables

Blood pressure
Cholesterol
HgbA1c.

Independent Variables

Participation in Project Dulce.

Control Variables

Age
Gender
Baseline variables.

Description of Actual Data Sample:

Initial N: 373
Attrition (final N): 354 (225 female)
Age: Dulce=51± 9 years, Control=52±10 years
Ethnicity: Diverse, predominately Latino
Location: San Diego, CA.

Summary of Results:

Key Findings

Changes in Clinical Outcomes Among Project Dulce Participants Compared with Control Participants.

Characteristics

Dulce

Control

Statistical Significance of Group Difference

HgbA1c

Pre: 8.5±2.4

Post: 7.3

Pre: 8.7

Post: 8.2

P<0.001

SE=0.2

Blood Pressure

(systolic, diastolic)

Pre:131.9, 76.7

Post: 124.8, 69.2

Pre: 130.0, 77.6

Post: 129.6, 77.5

P<0.001

SE=1.6, 1.0

Cholesterol (mg per dL)

Pre: 204.1

Post: 175.2

Pre: 213.9

Post: 207.3

P<0.001

SE=4.9

Other Findings

54% of Dulce participants had HgbA1c values less than 7% at follow-up measurements compared with 35% of controls (P=0.001)
68% of Dulce participants had blood pressure measurements less than 130/80mm Hg compared with 49% of controls (P<0.001)
54% of participants had LDL-C values of 100mg per dL or lower compared with 18% of controls (P<0.05). There were no significant differences in HDL-C.

Author Conclusion:

The study demonstrates improvements in clinical outcomes and reductions in hospital costs within the first year after implementation of a culturally appropriate diabetes management program in a low-income, ethnically diverse population. Evidence is provided that effective diabetes education and self-management training program can be conducted by non-physician staff.

The study design may have bias from self-selection of participants to the intervention who are sicker or healthier and who are more willing to accept therapeutic changes and follow medical recommendations. The sample was unbalanced with respect to gender and adherence to drug therapy was difficult to assess. The brief time period of the economic analysis does not capture the full effect of the intervention on complications and costs over the course of the disease. Studies of longer duration are necessary to determine how disease management affects costs in the long term.

Overall, the findings of reduced hospital expenditures, although statistically insignificant, is clinically and economically important and suggests than intervention might provide an immediate benefit for a high-risk population.

Funding Source:

Not-for-profit

The California Endowment

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?	???
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?	Yes
	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?		???
	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?		???
	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?	???
	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?		No
	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?	???
	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?	N/A
	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?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	???
	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)?	???
	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