Health Disparities

MNT: RDN in Medical Team (2015)

Citation:

Haskell WL, Berra K, Arias E, Christopherson D, Clark A, George J, Hyde S, Klieman L, Myll J. Multifactor cardiovascular disease risk reduction in medically underserved, high-risk patients. Am J Cardiol. 2006 Dec 1; 98 (11): 1,472-1,479. Epub 2006 Oct 12.

PubMed ID: 17126653
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

The purpose of this study was to evaluate the efficacy or effectiveness of a systematic approach to multi-factor cardiovascular disease (CVD) risk reductions in low-income, medically underserved patients.

Inclusion Criteria:
  • Informed consent obtained
  • Men and women aged 35 to 80 years
  • Had limited (Medicare without Part B or Medical) or no health insurance and low family income
  • At increased risk of having a clinical cardiac event due to existing vascular disease or increase in at least one major CVD risk factor
  • Currently receiving medical care at a not-for-profit or free clinic or hospital located in Santa Clara County, California
  • Willing to be randomized for 12 months.
Exclusion Criteria:
  • Recent history of serious medical condition:
    • Class II or III congestive heart failure, myocardial infarction, coronary artery bypass surgery, or percutaneous coronary intervention in the previous three months
    • Unstable angina pectoris or uncontrolled severe cardiac dysrhythmias
    • Severe chronic obstructive pulmonary disease
    • Cancer requiring surgery, radiation or chemotherapy.
  • Alcoholism
  • Severe psychiatric problems
  • If they were moving from the area within 12 months.
Description of Study Protocol:

Recruitment

  • Most patients recruited from four clinics
  • Eligible participants identified through review of medical records or by direct referral
  • Staff attempted to contact patients by telephone, in person at the clinics or by mail to determine interest, availability and eligibility for participation
  • Project explained to patients using a written project summary and consent forms in English or Spanish; interpreters were used for other languages.

Design

  • Baseline evaluation conducted on potential participants that included:
    • Comprehensive medical history
    • Physical examination
    • Blood pressure at rest
    • Heart rate
    • Body height and weight
    • Waist circumference
    • Fingerstick fasting blood sample for:
      • Glucose
      • Total cholesterol
      • Triglycerides
      • High-density lipoprotein (HDL) cholesterol
      • Low-density lipoprotein (LDL) cholesterol
    • Interviews to obtain demographic data:
      • Self-reported race or ethnicity
      • Cigarette smoking
      • Habitual physical activity
      • Dietary habits
      • Mental stress
      • Health-related quality of life
  • Then, patients randomized on a 1:2 ratio to either the usual care (UC) group or the disease management (UC+) group
  • Follow-up measurements were conducted at six and 12 months, using the same measurements and procedures as at baseline
  • At 12 months, all patients randomized to UC received disease management for 12 months, and those randomized to UC+ were enrolled in a maintenance program.

Intervention

  • UC group:  
    • Referred back to medical clinic from which they were recruited with a summary of their baseline evaluation for review by their medical provider
    • If a medical alert was identified during the evaluation, standard protocols were undertaken to ensure that the patient received immediate medical attention
  • UC+ group:
    • Intervention supervised by a physician
    • Conducted by a disease management team consisting of a specially trained nurse or nurse practitioner and a dietitian
    • Used algorithms based on national guidelines for decreasing CVD risk
    • Individualized plan implemented based on the patient's clinical and risk status, personal interest in making change, and resources available
    • Program used lifestyle changes and medical management, considering:
      • Smoking
      • Blood pressure
      • Lipids
      • Obesity
      • Glucose and diabetes status
      • Nutrition
      • Physical activity
      • Stress
    • Family members included when appropriate to support risk-decreasing efforts
    • Patient management strategies based on social-cognitive behavior change theories
    • Features of disease management model included:
      • Patient counseling
      • Point-of-care lipid and glucose testing
      • Use of existing community resources
      • Telephone and mail follow-up
      • Involvement of patients in their own care
    • Goal for seven to nine clinic visits (30 to 60 minutes each) with disease management team during the 12-month protocol: 
      • Months one to six: Every four to six weeks
      • Months seven to 12: Every eight weeks
    • Visits supplemented by telephone calls or correspondence as needed.

Statistical Analysis

  • Independent sample T-tests to compare baseline values of two treatment groups
  • Intention-to-treat analyses, comparing follow-up results of UC with UC+ patients who completed six- or 12-month evaluations
  • Analysis of covariance to examine the effects of the intervention using follow-up values adjusted for baseline values
  • Chi-square tests to compare percentages of participants in UC versus UC+ groups who moved from the high- and very-high-risk categories to increased- or low-risk categories.
Data Collection Summary:

Timing of Measurements

  • Baseline
  • Six months
  • 12 months
  • Follow-up data was an average of six- to 12-month follow-up visit values; or if patient had only one follow-up visit, that value was used.

Dependent Variables

  • Changes in CVD risk factors from baseline to follow-up:
    • Systolic blood pressure (mm Hg)
    • Diastolic blood pressure (mm Hg)
    • Total cholesterol (mg per dL)
    • LDL cholesterol (mg per dL)
    • HDL cholesterol (mg per dL)
    • Total cholesterol and high density cholesterol
    • Non-high-density cholesterol (mg per dL)
    • Triglycerides (mg per dL)
    • Fasting blood sugar (mg per dL)
    • BMI (kg/m2)
    • Waist circumference (cm)
    • Smokers (current)
    • Nutrition score
    • Physical activity score
    • Stress score
    • Quality of life (SF-12)
      • Physical score
      • Mental score
  • Change in CVD risk factor stratification (based on national guideline data) from baseline to follow-up:
    • Low
    • Increased
    • High
    • Very high
  • Change in medication use from baseline to follow-up:
    • Aspirin
    • Other antiplatelet therapy
    • Statins
    • Other hypolipidemics
    • Oral hypoglycemics
    • Insulin
    • Angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs)
    • Calcium channel blockers
    • Diuretics
    • Beta blockers
    • Other antihypertensives.

Independent Variables

Treatment condition (UC vs. UC+).

 

Description of Actual Data Sample:

Initial N

148 completed baseline visit.

Attrition (Final N)

  • 131 attended six-month visit (89%)
    • UC group: 40 (82%)
    • UC+ group: 91 (92%)
  • 135 attended 12-month visit (91%)
    • UC group: 42 (86%)
    • UC+ group: 93 (94%)
  • 141 attended either the six-month or 12-month visit (95%)
    • UC group: 45 (92%)
    • UC+ group: 96 (96%).

Age

Mean age ± standard deviation: 59.3±11.6 years

  • UC group: 56.8±12.6 years
  • UC+ group: 60.5±11.1 years. 

Ethnicity:

  • White: 17%
    • UC group: 29%
    • UC+ group: 11%
  • Hispanic: 57%
    • UC group: 53%
    • UC+ group: 59%
  • Asian: 10%
    • UC group: 6%
    • UC+ group: 11%
  • Black: 7%
    • UC group: 6%
    • UC+ group: 7%
  • Other: 10%
    • UC group: 6%
    • UC+ group: 12%.

Other Relevant Demographics

  • Gender: 56.7% female
    • UC group: 59.2% female
    • UC+ group: 55.6% female
  • No differences between UC and UC+ group in education, English-language fluency, primary language, or health insurance
  • The only significant differences at baseline between groups on medication use were:
    • Greater use of aspirin in the UC+ group
    • Greater use of ACE inhibitors and ARBs in the UC group.

Anthropometrics

There were no difference between treatment groups on any CVD risk factors except for BMI, waist circumference, and stress score.

  • BMI (kg/m2) (mean ± standard deviation): 31.4±6.6
    • UC group: 33.5±8.0
    • UC+ group: 30.4±5.5
  • Waist circumference (cm) (mean ± standard deviation): 101±15.5
    • UC group: 106±18.1
    • UC+ group: 98±13.4
  • Stress score (mean ± standard deviation): 8.2±4.9
    • UC group: 9.5±5.4
    • UC+ group: 7.8±4.5.

Location

 Santa Clara County, California.

Summary of Results:

 

Variables

UC Group Follow-up Measures

Mean ± Standard Error

UC+ Group Follow-up Measures

Mean ± Standard Error

Statistical Significance of Group Difference at Follow-up

Systolic blood pressure (mm Hg)

137±2.8 

128± 1.4

P<0.01

Diastolic blood pressure (mm Hg) 81±1.5  76±0.8 P=0.01
Total cholesterol (mg per dL) 197±4.8 184±3.4

P<0.01

LDL cholesterol (mg per dL) 115±4.4 104±2.9 P=0.03
HDL cholesterol (mg per dL) 44±1.6  46±1.2  P=0.02 
Total cholesterol and HDL cholesterol 4.8±0.17 4.3±0.13 P<0.001
Non-high-density cholesterol (mg per dL) 154±4.6 139±3.3 P=0.009
Fasting blood sugar (mg per dL) 149±7.9 123±3.6 P<0.05
Nutrition score 14.8±0.80 13.1±0.41 P=0.02
Physical activity score 11.6±1.40 8.0±0.93 P=0.02

  • Adjusting for baseline measures, differences between groups were not statistically significantly different at follow-up for:
    • Triglycerides
    • BMI
    • Waist circumference
    • Smoking status
    • Stress score
    • Quality of life (SF-12)
      • Physical score
      • Mental score.

 
Variable
UC Group UC+ Group  

Statistical Significance of Group Difference at Follow-up

Percent of Subjects in Very High or High-Risk Categories at Baseline Percent of Subjects in Very High or High-Risk Categories at Follow-up Percent of Subjects in Very High or High-Risk Categories at Baseline Percent of Subjects in Very High or High-Risk Categories at Follow-up

Systolic blood pressure

57%

39%

53%

17%

P=0.009
LDL cholesterol

34%

27%  37% 14% P=0.02

  • Changes from very high or high to increased or low categories in the UC+ versus the UC group were statistically significant for:
    • Systolic blood pressure
    • LDL cholesterol
    • Diastolic blood pressure
    • Total cholesterol
    • Total cholesterol and HDL cholesterol ratio
    • Fasting blood sugar
  • Adjusting for baseline values, significant increases in medication use from baseline to 12 months were found in the UC+ group compared with changes for the UC group for:
    • Aspirin
    • Statins
    • ACE inhibitors and ARBs
    • Beta blockers.

 

Author Conclusion:

The disease management program had excellent retention and lower CVD risk factors and demonstrated the potential of such approaches for decreasing long-term disease burden in selected medically underserved populations.

Funding Source:
Other: No funding source information provided
Reviewer Comments:

Although the UC+ group had significantly lower BMI and waist circumference values at baseline, the follow-up values adjusted for baseline measures.  

One limitation to this study is that participants were recruited from clinics or hospitals, indicating that these participants are likely to seek health care. Furthermore, approximately 50% of the people who were eligible for the study could not be contacted by telephone or letter because many had moved with no forwarding contact. These findings cannot be generalized to those underserved people who do not seek health care or to those who move frequently. 

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? No
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? No
  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? 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? ???
  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? ???
  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? 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)? Yes
  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? 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? Yes
  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? No
  10.2. Was the study free from apparent conflict of interest? Yes