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Does Literacy Impact the Effectiveness of Does Literacy Impact the Effectiveness of a Disease Management Program in a Disease Management Program in

Congestive Heart Failure?Congestive Heart Failure?

AcademyHealth 2004 Annual Research Meeting June 8, 2004

Brad Smith, Robert Ellis, Emma Forkner, Richard A. Krasuski, Michael Kwan, Karl Stajduhar, Autumn Dawn Galbreath, and Gregory L. Freeman

Presented by: Brad SmithSenior Analyst, Altarum InstituteProject Statistician, UTHSCSA-Disease Management CenterE-mail: brad.smith@altarum.orgTel: 210-832-3000 Fax: 210-567-9712

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IntroductionIntroduction

Rising health care expenses have led payors and health care systems to seek out new approaches to cost containment for chronic diseases.

Disease management (DM), a comprehensive, multidisciplinary, therapeutic and educational intervention, has been shown to improve outcomes and reduce utilization costs in a number of trials

Published trials have generally been small and have been conducted in employed, group-insured populations.

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IntroductionIntroduction

The effectiveness of DM in a more broadly representative group remains relatively unexplored.

Broader population presents a variety of challenges to DM including

• Access to primary care and pharmacy

• Literacy

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IntroductionIntroduction

The impact of literacy on the effectiveness of DM is an important issue to explore given

– The association of literacy with a number of important chronic disease care outcomes (e.g. AHRQ’s Literacy and Health Outcomes, 2004 and IOM report on health literacy)

– Centrality of provider-patient communication to the success of DM programs

– Trends toward expansion of DM programs beyond employed, group-insured populations (e.g. mandatory DM for asthma patients in Texas’ Medicaid program)

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QuestionQuestion

How does literacy, as measured by educational attainment, impact the primary and secondary outcomes in a randomized, controlled trial of a disease management program in congestive heart failure patients?

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Methods: Study DesignMethods: Study Design

Community-based, single-center, randomized, controlled clinical trial performed between 1999 and 2003 at the University of Texas Health Science Center at San Antonio

Enrolled a total of 1,069 male and female subjects 18+ years old with documented congestive heart failure (CHF) from throughout South Texas

Followed patients over 18 months with 4 equally spaced clinic visits.

This sub-study focuses exclusively on the pooled DM arms (N=710)

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Methods: DM InterventionMethods: DM Intervention

Telephonic intervention by RN with specialized training in CHF management

Comprehensive written patient education guide in both English and Spanish targeted to 8th grade reading level

Key components of the disease management intervention– initiation and upward titration of all recommended drug classes for

CHF

– Verbal instruction and written reference on

• appropriate cardiac diet (low fat, low sodium, fluid restricted)

• medication compliance

• suitable exercise regimen

• appropriate reaction to signs of the onset of a CHF exacerbation.

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Methods: MeasuresMethods: Measures

Primary outcomes– Clinical: Mortality and event-free survival, ejection fraction, exercise

tolerance– Utilization: inpatient stays and emergency department visits

Secondary outcomes– Daily dietary sodium intake in milligrams as measured by the Food

Frequency Questionnaire – Self-confidence to manage the symptoms of CHF (0-100 ordinal scale)

Independent variables:– Educational attainment is a proxy for literacy (ordinal)– Other controls:

• Primary outcome models: type of heart failure, baseline beta blocker status, NYHA class, gender, race/ethnicity, age

• Secondary outcome models: NYHA class, gender, race/ethnicity, age, primary language and household composition.

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Sample ProfileSample Profile

Study sample is less well-educated than the general population in South Texas

– 43.7% HS diploma or less in study sample

– 34.0% HS diploma or less in South Texas (Census statistics)

Sample is otherwise largely Caucasian (70%), male (70%), older (average age 70.5), English-speaking (94%) and living with family or spouse (77%)

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Outcomes: Clinical and Utilization MeasuresOutcomes: Clinical and Utilization Measures

There was no statistically significant difference in change in ejection fraction, exercise tolerance, mortality or cardiac event-free survival by educational attainment.

No statistically significant difference was observed in the rate of visits to the emergency department or in the rate of inpatient hospital stays.

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Outcomes: Dietary Sodium ReductionOutcomes: Dietary Sodium Reduction

The likelihood of a reduction in daily sodium intake was higher among those with at least some college training than among those with a high school degree or less.

The magnitude of the drop was also larger in the better educated group.

Some College

HS Diploma or less

0.0 0.2 0.4 0.6 0.8

p=0.012

Predicted Probability of a Drop in Dietary Sodium Intake

0.73

0.81 Some College

HS Diploma or Less

-600 -500 -400 -300 -200 -100 0

p=0.018-614.4

-436.4

Decrease in Dietary Sodium Intake in mg/ day

Note: Predicted probabilities computed based on logistic regression results. Size of decrease estimated by OLS. Both models adjusted for age, sex, race/ethnicity, spanish language and household composition (alone vs not alone)

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Outcomes: Symptom Self-Management ConfidenceOutcomes: Symptom Self-Management Confidence

Confidence in one’s ability to manage the symptoms of CHF was more likely to increase among those with at least four years of college than among those with less education.

The magnitude of the difference in the self-confidence scores between the two groups was not, however, statistically or substantively significant (2.34 on a 100 pt scale, p=ns).

Fewer than four years of college

Four years or more of college

0.0 0.1 0.2 0.3 0.4 0.5 0.6

p=0.0250.56

Predicted Probability of Improvement in Symptom Self-Management Confidence

0.45

Note: Predicted probabilities computed from a logistic regression adjusted for age, sex, race/ethnicity, Spanish language and household composition (alone vs not alone)

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ConclusionsConclusions

Educational attainment had a limited impact on the secondary, but not the primary, outcomes of a disease management program in CHF.

To gain a more complete picture of how literacy impacts DM outcomes, it will be critical to develop and employ state of the art tools for assessment of health literacy in future studies.