DISCUSSION
Subject mean scores on the Self-Efficacy for Exercise Behavior Scale were less than 70% suggesting that study participants had an increased risk for exercise drop out. Since this instrument was developed using a sample of adults from the general population, these results are not surprising.35 Patients with CHD are in poorer health than their age or gender mates in the general population, and of- ten have additional co-morbidities. People with CHD also have an increased incidence of depression compared to the general population. We postulate that making the time and expending the energy to build exercise into one’s daily rou- tine is difficult for healthy adults, and possibly even more so for those with CHD who have a limited energy reserve
due to impaired cardiac function. Sarkar and colleagues40 found that lower cardiac self-efficacy was associated with greater symptom impact, more impaired physical function, lower quality of life, and lower health status in patients with CHD.
The correlation between exercise self-efficacy for resist- ing relapse and income suggests that patients with higher income were more confident in adhering to exercise, even when barriers were present. This finding may be due to several factors, including that people with higher income have more time and resources available to support and maintain exercise behavior, even when external factors like household chores, work requirements and/or social obligations are present. These findings are consistent with those of Clark et al,41 who found that exercise self-efficacy is positively correlated with income. It is also possible that individuals with higher income levels have less physically demanding jobs, resulting in less fatigue at the end of the work day, and therefore more energy to engage in exercise. However, the majority of study participants were retired, so it would be important to consider the relationship between physical work demands and adherence to exercise in a population of adults with CHD who are in the workforce.
Study findings also suggest that participants with higher physical function were more confident returning to physi- cal activity and managing any cardiac-related symptoms experienced. Patients with lower physical function may have a limited repertoire of physical activities in which to