Relation of Perceived Health Competence to Physical Activity in Patients With Coronary Heart Disease.

Physical inactivity is highly associated with mortality, especially in patients with coronary heart disease. We evaluated the effect of perceived health competence, a patient's belief in his or her ability to achieve health-related goals, on cumulative physical activity levels in the Mid-South Coronary Heart Disease Cohort Study. The Mid-South Coronary Heart Disease Cohort Study consists of 2,587 outpatients (32% were female) with coronary heart disease at an academic medical center network in the United States. Cumulative physical activity was quantified in metabolic equivalent (MET)-minutes per week with the International Physical Activity Questionnaire. We investigated associations between the 2-item Perceived Health Competence Scale (PHCS-2) and MET-minutes/week after adjusting for co-morbidities and psychosocial factors with linear regression. Nearly half of participants (47%) exhibited low physical activity levels (<600 MET-minutes/week). Perceived health competence was highly associated with physical activity after multivariable adjustment. A nonlinear relation was observed, with the strongest effect on physical activity occurring at lower levels of perceived health competence. There was effect modification by gender (p = 0.03 for interaction). The relation between perceived health competence and physical activity was stronger in women compared with men; an increase in the PHCS-2 from 3 to 4 was associated with a 73% increase in MET-minutes/week in women (95% confidence interval 43% to 109%, p <0.0001) compared with a 53% increase in men (95% confidence interval 27% to 84%, p <0.0001). In conclusion, low perceived health competence was strongly associated with less physical activity in patients with coronary heart disease and may represent a potential target for behavioral interventions.