Understanding physical activity during home-based cardiac rehabilitation from multiple theoretical perspectives

: Previous studies have shown that moderate-to-vigorous physical activity (MVPA) levels during home-based cardiac rehabilitation (CR) have been problematic. Consequently, the present study examined the utility of the theory of planned behavior, protection motivation theory, and social cognitive theory in explaining physical activity (PA) during a Canadian home-based CR program.

: Patients (N = 280, mean age 62.8 years; 95.4% white, 72.5% male, 78.9% married, 52.3% retired, 48.0% income more than $60000; and 33.8% postmyocardial infarction) completed a questionnaire at program onset and a MVPA assessment at 3-month followup.

: Path analyses showed that each theory accounted for 28% to 34% of the variance in PA. The theory of planned behavior showed that perceived behavior control was the key predictor of 3-month MVPA (β = .36), whereas protection motivation theory showed that intention (β = .30) was the key predictor. Finally, barrier self-efficacy (β = .21) and the availability of home PA equipment (β = .15) were the key predictors of 3-month MVPA within social cognitive theory.

: All 3 theories appeared to be viable options to inform the development of a MVPA intervention during home-based CR. However, the key constructs to target within each theory varied, suggesting the need to potentially use multiple theories to inform intervention development.