Abstract
Background: Patients with implantable cardioverter-defibrillators (ICDs) face problems in physical function, but little is known about how mastery predicts physical function over time.
Purpose: The primary purpose of this study was to examine the influence of mastery (assessed at baseline) on physical function (observed distance walked and perceived function) over 12 months among ICD patients. Secondary purposes were to (1) examine the influence of aging, in interaction with mastery, on physical function and (2) determine predictors of 12-month physical function.
Methods: The ICD patients (N = 122; 75% men; 88% white; mean age, 65 years) completed the baseline interviews; 100 patients completed the 12-month interviews. Repeated-measures 1-way analyses of variance were used to examine the influence of mastery and the interaction of mastery and aging on physical function over 12 months. Multiple regression analyses were conducted to determine predictors of 12-month physical function.
Results: The ICD patients with higher mastery had better walk distances than those with lower mastery; and walk distances were improved over 12 months, but only in those with lower mastery (F = 5.40, P = .02). The ICD patients with higher mastery had better perceived physical function than those with lower mastery (F = 25.57, P < .0001), but those with both lower and higher mastery did not show significant improvement. Neither significant interaction of aging and mastery on physical function nor predictors of walk distances were found. Baseline depression significantly predicted 12-month perceived physical function (F = 8.94, P = .0042).
Conclusions: The ICD patients with lower mastery had considerable impairments in physical function compared with those with higher mastery over time. Depression is more likely to predict perceived physical function. Further prospective studies are needed to validate these findings in a larger sample and develop interventions to improve physical impairment in ICD patients.