The association of frailty on cardiac rehabilitation goal achievement

Introduction: Frailty is common among patients entering cardiac rehabilitation (CR). Frailty is associated with poor health outcomes; however, it is unclear if frailty influences achieving goals in CR. Methods: We report a secondary analysis of participants who were referred to an exercise and education-based CR program from 2005 to 2015. Frailty was measured by a 25-item accumulation of deficits frailty index (FI) ranging from 0 to 1; higher scores indicate higher frailty. Participants were categorized by admission frailty levels (FI scores: < 0.20, 0.20-0.29, 0.30-0.39, > 0.40). CR goals were determined with shared decision-making between CR staff and the patients. We conducted logistic regression analyses to examine the odds of goal attainment by CR completion, adjusting for age, sex, education, marital status, and referring diagnosis. Analyses were performed using baseline frailty as a categorical and continuous outcome, and frailty change as a continuous outcome in separate models. Results: Of 759 eligible participants (age: 59.5 +/- 9.8, 24% female), 607 (80%) participants achieved a CR goal at graduation. CR goals were categorized into similar themes: control or lose weight (n = 381, 50%), improve physical activity behaviour and fitness (n = 228, 30%), and improve cardiovascular profile (n = 150, 20%). Compared to the most severe frailty group (FI >0.40), lower levels of frailty at baseline were associated with achieving a goal at CR completion [FI < 0.20: OR = 4.733 (95% CI: 2.197, 10.194), p < .001; FI 0.20-0.29: OR = 2.116 (1.269-3.528), p = .004]. Every 1% increase in the FI was associated with a 3.5% reduction in the odds of achieving a CR goal [OR = 0.965 (0.95, 0.979), p < .001]. Participants who reduced their frailty by a minimally clinically important difference of at least 0.03 (n = 209, 27.5%) were twice as likely to achieve their CR goal [OR = 2.111 (1.262, 3.532), p = .004] than participants who increased their frailty by at least 0.03 (n = 82, 10.8%). Every 1% improvement in the FI from baseline to follow up was associated with a 2.7% increase in the likelihood of CR goal achievement [OR = 1.027 (1.005, 1.048), p = .014]. Conclusion: Lower admission frailty was associated with a greater likelihood of achieving CR goals. Frailty improvements were associated with CR goal achievement, highlighting the influence of frailty on goal attainment.