The measurement properties of fitness measures and health status for persons with spinal cord injuries

Stewart MW, Melton-Rogers SL, Morrison S, Figoni SF. The measurement properties of fitness measures and health status for persons with spinal cord injuries. Arch Phys Med Rehabil 2000;81:394-400. Objective: To assess the measurement properties of measures used to evaluate fitness and health status in the spinal cord injury (SCI) population. Design: Inception cohort assessed during standardized exercise protocols at admission, discharge, and 8-week follow-up from a SCI rehabilitation program. Setting: Urban tertiary care hospital. Patients: One hundred two patients with SCI. Results: Measures at higher levels of physical exertion generally showed higher stability between test and retest. Resting measures, blood lactates, and respiratory exchange ratios were not stable. Heart rate, blood pressure, lactate levels, ventilation rates, and activities of daily living measures did not reflect the construct of aerobic fitness. The use of ratings of perceived exertion to predict heart rate was found to be inaccurate in the SCI population. Conclusion: Power output and V̇O2 at maximal workload, and ratings of perceived exertion at a standard workload demonstrated stability and sensitivity to therapeutic change, indicating acceptable measurement properties for the assessment of aerobic fitness in SCI patients. Some other commonly used measures can be used with less confidence. © 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation