Motivational Interviewing (MI) for African Americans With Peripheral Arterial Disease (PAD)

Overview

The investigators are conducting a clinical research trial to determine the role of motivational interviewing (MI) on promoting home-based walking therapy to improve walking ability in African Americans with peripheral arterial disease (PAD). African Americans are more than two times as likely as non-Hispanic whites to suffer from PAD. For patients with PAD, there is a significant risk for poor walking ability and limb loss. One major treatment for PAD is walking therapy but the traditional methods for the delivery of this treatment have required frequent visits to a university or hospital-based site. The investigators will address the role of self-managed walking program, to be conducted at or near the home, to improve limb function. In order to motivate the participants to walk, the investigators included two different intervention strategies: MI and patient-centered counseling for exercise (PACE). The investigators hypothesize that participants randomized to the MI arm will have a greater increase in their walking distance, compared to those receiving Patient-Centered Assessment and Counseling for Exercise (PACE) and the control group.

MI is an effective counseling method in individuals who are less ready to change their behavior (i.e., low motivation). Thus, MI is an ideal counseling method to promote home-based walking among AAs with PAD. In our pilot study to promote home-based walking, we used a counseling protocol, Patient-centered Assessment and Counseling for Exercise (PACE)(Sallis et al), which targets known modifiable determinants of behavior change (e.g., social support). Using PACE, we demonstrated an improvement in stair climbing ability and lower limb blood flow (as measured by the ankle-brachial index). Improvements in these lower limb outcomes offer support for the use of PACE counseling in PAD, but PACE does not specifically address low motivation - a critical target for AAs with PAD. In addition, PACE is not culturally sensitive. In our proposed trial, we hypothesize that MI will improve walking distance and reduce walking impairment more than PACE in AAs with PAD. There is a critical need to improve lower limb outcomes in AAs with PAD. Our long-term goal is to reduce debilitating functional limitations and amputations in AAs with PAD. The overall objective of this application is to determine the most effective counseling strategy to improve home-based walking in AAs with PAD. We have assembled an excellent and diverse research team with the requisite skills and experience needed for this study. Moreover, we have robust pilot data to support the study hypotheses and ensure successful completion of the study. We will deliver the PACE protocol or MI for 6 months, using both face-to-face visits and telephone contact. Our primary outcome is walking distance (as measured by the widely used and well-validated 6-minute walk test) at the end of active intervention (6 months). Secondary outcomes are walking distance as measured beyond the active phase of intervention (12 months), use of home-based walking (as measured by accelerometry), and lower limb blood flow (as measured by the ankle brachial index - ABI). Our comparison group will receive the same print material as the two interventions as well as contact every three months to update any changes in contact information and to assess their health status. We will randomize 204 participants to one of three arms: Control or Treatment One (Tx1); PACE or Treatment Two (Tx2); or MI, also referred to as Treatment Three (Tx3). In addition, we will determine the efficacy of PACE (Tx2) to increase walking distance in AAs with PAD, compared to Control (Tx1). Primary Hypothesis: 1\. At 6 months, AAs with PAD randomized to MI (Tx3) will have a greater increase in their walking distance, compared to those receiving PACE (Tx2) and the control group (Tx1). Secondary Hypotheses: 1. AAs with PAD randomized to MI (Tx3) will have a greater increase in their walking distance at 12 months - a follow-up period beyond the six months of active intervention - compared to those receiving PACE (Tx2) and compared to the control group (Tx1). 2. At 6 and 12 months, AAs with PAD randomized to MI (Tx3) will have a greater increase in their home-based walking and their lower limb blood flow, compared to those receiving PACE (Tx2) and to the control group (Tx1). 3. At 6 and 12 months, AAs with PAD randomized to PACE (Tx2) will have a greater increase in their walking distance compared to those randomized to control (Tx1). Exploratory Aim: We will explore potential mediators (self-efficacy, social support, intrinsic/extrinsic motivation) and moderators (co-morbidities, leg symptom type, stage of change) of intervention effects on walking distance, home-based walking, and lower limb blood flow among AAs with PAD.