Utility of the Late Life Function and Disability Instrument as an Outcome Measure in Patients Participating in Outpatient Cardiac Rehabilitation: A Preliminary Study

Abstract

The purpose of this study was to examine the concurrent validity of the Late Life Function and Disability Instrument (LLFDI) in patients with coronary heart disease (CHD) and to evaluate the accuracy of information obtained through self-report questionnaire versus interview formats. The study included 29 patients older than 60 years attending an outpatient cardiac rehabilitation program. Participants completed the LLFDI, three additional self-report criterion measures, and six performance-based tests; they completed the LLFDI a second time via interview. We used descriptive statistics, correlations, and t-tests to analyze the data. All LLFDI components were correlated (rs=0.36-0.83) with the self-report criterion measures. The Function Component of the LLFDI was moderately correlated with the 6-Minute Walk Test (r=0.62), timed up-and-go (r=-0.58), walking speed (r=-0.57), and timed sit-to-stand (r=-0.56) scores. The LLFDI demonstrated a ceiling effect (10%) only in the Disability Limitation component. All LLFDI component scores obtained via self-report questionnaire were correlated with scores obtained via interview; except in a single subcategory, there was no difference between LLFDI scores obtained through self-report questionnaire and those obtained through interview. RESULTS indicate that the LLFDI has appropriate validity for older patients (>60 years) with CHD and can be completed independently by patients rather than administered by clinicians.