Walking speed threshold for classifying walking independence in hospitalized older adults

Abstract

Background. Walking speed norms and several risk thresholds for poor health outcomes have been published for community-dwelling older adults. It is unclear whether these values apply to hospitalized older adults. Objective. The purpose of this study was to determine the in-hospital walking speed threshold that best differentiates walking-independent from walkingdependent older adults. Design. This was a cross-sectional study. Methods. This study recruited a convenience sample of 174 ambulatory adults aged 65 years and older who had been admitted to a medical-surgical unit of a university hospital. The participants' mean (SD) age was 75 (7) years. Fifty-nine percent were women, 66% were white, and more than 40% were hospitalized for cardiovascular problems. Usual-pace walking speed was assessed over 2.4 m. Walking independence was assessed through self-report. Several methods were used to determine the threshold speed that best differentiated walking-independent patients from walking-dependent patients. Approaches included a receiver operating characteristic (ROC) curve, sensitivity and specificity, and frequency distributions. Results. The participants' mean (SD) walking speed was 0.43 (0.23) m/s, and 62% reported walking independence. Nearly 75% of the patients walked more slowly than the lowest community-based risk threshold, yet 90% were discharged home. Overall, cut-point analyses suggested that 0.30 to 0.35 m/s may be a meaningful threshold for maintaining in-hospital walking independence. For simplicity of clinical application, 0.35 m/s was chosen as the optimal cut point for the sample. This threshold yielded a balance between sensitivity and specificity (71% for both). Limitations. The limitations of this study were the small size of the convenience sample and the single health outcome measure. Conclusions. Walking speeds of older adults who are acutely ill are substantially slower than established community-based norms and risk thresholds. The threshold identified, which was approximately 50% lower than the lowest published community-based risk threshold, may serve as an initial risk threshold or target value for maintaining in-hospital walking independence. © 2010 American Physical Therapy Association.