Heart patients with beliefs about health that aren't based on medical evidence are more likely to skip sessions of cardiac rehabilitation, new research suggests.
In the Ohio State University study, a higher number of these beliefs - referred to as "irrational health beliefs" on a standard measure of these thoughts - was associated with lower adherence to a prescribed cardiac rehab program.
Among the irrational beliefs assessed: Doubting the preventive power of the flu vaccine or believing, based on family history alone, that it's safe to smoke cigarettes and carry excess weight after a doctor's warning about health risks linked to these behaviors.
Beyond these beliefs, a few demographic factors influenced adherence to a rehabilitation program. On average, older participants and those with higher incomes attended a higher percentage of sessions, while African Americans, on average, attended a smaller percentage of sessions than did whites.
Among those factors, African-American patients were more likely than white participants to have a higher number of irrational health beliefs.
"These beliefs about health haven't been looked at in a cardiac population before," said Charles Emery, professor of psychology at Ohio State and senior author of the study.
"Most patients referred to cardiac rehab have been sedentary. Though they are in a supportive environment, exercise is still not necessarily pleasant and can be painful from time to time. So it's important to examine factors that might negatively influence them and then intervene to address those factors - in this case, their irrational health beliefs."
Emery conducted the research with Derek Anderson, lead author and a doctoral candidate in psychology at Ohio State. The study is scheduled to appear in an upcoming issue of the journal Health Psychology, and is currently available online.
Improving adherence to a rehabilitation program is critical, Emery said, because cardiac rehab already has strikes against it: Only about a third of eligible patients enter rehabilitation for a variety of reasons, including a low referral rate by cardiologists, insurance limitations and responsibilities at home and work. This is despite the fact that cardiac rehabilitation lowers the risk of a future heart problem by slowing the progression of disease, according to the American Heart Association.
"In terms of intervening, this study would point the finger at irrational health beliefs as one relevant target. Providing more education and evidence-based medical information to these patients may help enhance adherence," said Emery, also a professor of internal medicine and investigator in Ohio State's Institute for Behavioral Medicine Research.
The study had a relatively small sample size - 61 participants - but had typical demographics for a cardiac rehab program: A majority (70.5 percent) were men and the group's average age was almost 60. However, 23 percent of participants were African American, which is a relatively large proportion for studies in this area.
Almost all patients were prescribed a typical 36-session rehab program, with exercise three times per week for one hour plus an hour a week of education about nutrition, stress management and smoking cessation.
Before the first rehab session, participants completed questionnaires measuring depression and irrational health beliefs. The Irrational Health Belief Scale contains 20 vignettes describing a health-related experience in which a narrator makes distorted or illogical assumptions about health. Respondents are asked to rate each item on a scale of 1 ("not at all like I would think") to 5 ("almost exactly like I would think").
Overall, participants completed, on average, almost 75 percent of sessions approved by their insurance providers. A higher percentage of exercise session completion was associated with higher income and older age, but African-American patients completed a lower percentage of sessions than did white patients.
Gender, marital status and employment status had no effect on rehab adherence. Though researchers predicted that more education would be linked to fewer irrational health beliefs, that relationship did not pan out.
Though the study could not explain why African Americans were more likely among this group to have irrational health beliefs, Emery suggested that experience with doctors and hospitals could play a role.
"Exposure to the health care system is likely to increase someone's knowledge of medicine, and therefore irrational health beliefs should decrease with more exposure. And good population data suggest that African Americans underutilize health care for various reasons, so that could be one reason for the observed racial difference," he said.
The study also showed that depression was not linked to lower adherence to the rehab program, countering Emery's previous findings that depression was related to poor rehab adherence.
"That was unexpected, to find that depression wasn't related to adherence," Anderson said. "But we did find that patients with more depressive symptoms were also more likely to have irrational health beliefs."
Emery and Anderson suggested that the data support a closer look into irrational health beliefs, and how they might influence such health behaviors as diet, smoking and alcohol use in cardiac patients and in others with chronic health problems. Anderson is currently continuing this work by examining factors that affect behavior after cardiac rehab is finished.