Validation of an Effective and Easily-Administered Walk Test Measure of Functional Status in Heart Failure Patients: Comparison of the 60 Foot and 6 Minute Walk Tests

Objective: To validate and compare a new, quick, and easy 60ft walk test (WT) with the standard 6 minute walk test (6MWT) for functional evaluation in heart failure (HF). Hypothesis: The 60ft WTand 6MWT will provide comparable information regarding measurement of functional status and predictive value of health outcomes in HF patients. Methods: 63 HF patients were evaluated with the 60ft WT and 6MWT. Compared to the 6MWT, the 60ft WT is less time consuming and can be performed in a smaller area. Patients completed 4 laps of 15ft; the time taken to walk each lap was recorded in seconds (s). The 6MWT measured the distance walked in 6 minutes. Patients completed the Kansas City Cardiomyopathy Questionnaire (KCCQ); B-type natriuretic peptide (BNP) level was measured. Hospitalizations were assessed for up to 12 months. Results: At baseline, average 60ft WT lap time was correlated with total distance on the 6MWT (r = -0.73, p < .001). Both WTs were correlated with subscales on the KCCQ, including Symptom Frequency, Total Symptom, Clinical Summary, and Overall Summary (60ft WT: r's = -0.27 to -0.32; 6MWT: r's = 0.35 to 0.48). Only the 6MWT correlated with KCCQ Physical Limitation (r = 0.32, p = .016) and Symptom Burden (r = 0.33, p = .015), whereas only the 60ft WT correlated to Self-Efficacy (r = 0.32, p = .016). Both WTs were comparably correlated with BNP in the expected directions (60ft WT: r = 0.42, p = 0.004; 6MWT: r = -0.49, p = .001). Hospitalizations occurred in 19 of 63 patients (28.8%) and were predicted by baseline 6MWT (OR = 0.996, p = .012) after controlling for age, gender, and body mass index (BMI). For every 10ft increase in distance walked, there was a 4% lower risk of hospitalization. Predictive value of the baseline 60ft WT was stronger (OR = 1.74, p = .012); every 1s increase in average lap time resulted in a 74% greater risk of hospitalization. Conclusions: The 60ft WT provides much of the same information as the 6MWT, but is completed in less than 1 minute, in a smaller 15ft area, and is less influenced by reduced patient mobility. This new method has high clinical validity, applicability in an office setting, and reduces the burden of functional status testing on patients and health professionals.