JoEllen Wilbur, PhD, APN, FAAN, Funded Projects
Adherence to Walking: Strategies for Midlife Minority Women
Funding Source: National Institute of Nursing Research
Dates: 8/15/01 – 5/31/07
Co-Investigators: Arlene Miller, Barbara Dancy, Judith McDevitt, Ed Wang
View Poster: PowerPoint File
Abstract: The purpose of this study is to test the efficacy of a 48-week home-based walking intervention for low-income midlife (45-65 years) African American (AA) women. The intervention is enhanced by behavior strategies tailored to a woman's community and personal characteristics (Enhanced treatment). The specific aims are (1) to describe the changes in adherence-enhancing factors (social influence, interpersonal characteristics-cognition, attitude and motivation) and health-status outcomes cardiovascular [CV] health and symptoms) for both the Enhanced Treatment (ET)and a Standard Treatment (ST) without the behavioral strategies at baseline, 24, 48, and 72 weeks; (2) to compare women receiving the ET to the women in the ST on adherence-enhancing factor, exercise adherence indicators (frequency, duration, and intensity of exercise; patterns of adherence; energy expenditure)and health status at 24, 48 and 72 weeks; (3) to identify the relationships among adherence-enhancing factors, exercise adherence indicators, and health-status outcomes. The ET will be randomly assigned to one of two health centers in the Chicago Westside where heart disease is among the highest in the city. Subjects will include 240 sedentary women who have no major signs or symptoms of CV disease; no history of myocardial infarction, stroke, or Type 1 diabetes; and are not on a beta blocker, Ditiazem or Verapamil. Women will be recruited from low-income communities surrounding the two health centers. Women (both treatments) will be oriented to the walking prescription, which is moderate intensity, a minimum of three 30-minute sessions per week. During the 24-week active phase, the ET receives a combined behavioral package of community-focused strategies delivered by community workers via workshops tailored to the women's environmental characteristics, and individually-focused strategies delivered via phone tailored to each women's personal characteristics. During the 24-week maintenance phase, women in the ET receive phone calls monthly or bimonthly, depending on their adherence. Both treatment groups will self-monitor their performance with heart rate monitors, enter exercise-log data via a voice response system, and have three face-to-face visits with the community worker during each phase. During the 24-week follow-up phase, neither group receives behavior strategies. The Physical Activity Behavior Framework, derived from Cox's Interaction Model of client Health Behavior, will guide the intervention. Analyses include descriptive statistics, change scores, and mixed-effects regression models for the longitudinal data.
Environmental Correlates and Adherence of Home-based Walking in African American Women
Funding Source: Robert Wood Johnson Foundation
Dates: 4/1/05 – 6/30/07
Co-Investigators: Judith McDevitt, Edward Wang, Shannon Zenk, Sue McNeil
Abstract: Background: Factors such as the built and social environments have been ignored as possible determinants of physical activity patterns. Despite the disproportional higher risk for cardiovascular disease (CVD) and higher CVD morbidity and mortality among African-American (AA) women, most interventional research has failed to substantially alter physical activity behavior. Perhaps it has focused too narrowly on personal correlates of physical activity adherence. Environmental correlates may be particularly salient for AA women because of race-based residential segregation, making them more likely to live in neighborhoods that do not support physical activity. Guided by a model adapted from social cognitive theory, we will link objective environmental measures developed using geographic information system (GIS) technology to interventional personal data from an ongoing NIH-funded walking program for AA women.
Specific aims: The specific aims are to: 1. determine the extent to which community neighborhood dimensions of the built (walkability, aesthetics, and access to walking facilities) and social (safety, socioeconomic position, residential stability, and sense of community) environments influence physical activity health behavior (i.e., adherence to a home-based moderate-intensity walking intervention) during the adoption (baseline to 24 weeks) and maintenance (25 to 48 weeks) phases;
2. determine the extent to which dimensions of the built and social neighborhood environments influence changes in intrapersonal correlates (self-efficacy related to walking) of physical activity; and 3. examine the mediating effects of intrapersonal correlates (self-efficacy) on relationships between the built and social environments and adherence at 24 and 48 weeks to a home-based moderate-intensity walking program.
Method: Design: Objective measures of neighborhood environmental characteristics will be linked with data collected as part of an ongoing clinical trial of two versions of a walking intervention conducted with 259 sedentary AA women at risk for CVD. Measures: Objective measures of built and social environments will be quantified using ArcView 3.3. Most environmental measures will characterize the woman's immediate neighborhood, defined as a one-mile radius around a geocoded home address. Adherence and maintenance of the intervention will be quantified from heart rate monitoring and weekly reporting of walks via a telephone response system. Other measures available from the clinical trial include: a sense of community; perceived social environment; self-efficacy for overcoming exercise barriers and exercise self-efficacy; social support for exercise; and body mass index. Analyses: Structural Equation Modeling (SEM) will be used to analyze data. A confirmatory factor analysis of SEM will be applied to test the specific hypotheses and verify the proposed conceptual model. Covariance matrix and structural coefficients will be calculated to explore and verify relationships among these variables and test the study's main hypotheses.
Conclusions: The strengths of this study include GIS measures of environment factors likely to affect physical activity behaviors in women disproportionately vulnerable to CVD; linkages to existing personal data on women receiving a well-designed moderate-intensity, home-based walking program; and testing of a broadened ecological model of physical activity. Knowledge gained from this study will be used to incorporate salient environmental factors along with validated personal correlates into interventions to optimize physical activity behaviors in AA women.