RESUMEN
BACKGROUND: Bedrest is toxic for inpatients and consumer grade physical activity monitors offer an economical solution to monitor patient ambulation. But these devices may not be accurate in debilitated hospitalized patients who frequently ambulate very slowly. OBJECTIVE: To determine whether measures of physical capacity can help identify inpatients for whom wearable physical activity monitors may accurately measure step count. METHODS: Prospective observational study of 54 adult inpatients with acute neurological diagnoses. Patients were assessed using 2 physical capacity assessments (Activity Measure for Post-Acute Care Inpatient Mobility Short Form [AM-PAC IMSF] and Katz Activities of Daily Living [ADL] scale). They also completed a 2-minute walk test (2MWT) wearing a consumer grade physical activity monitor. RESULTS: The wearable activity monitor recorded steps (initiated) in 33 (61%) of the inpatients, and for 94% of inpatients with gait speeds >0.43 m/s. Physical capacity assessments correlated well with gait speed, AM-PAC IMSF r = 0.7, and Katz ADL r = 0.6, p < 0.05. When the physical activity monitor initiated, the mean absolute percent error (SD) comparing device calculated steps to observed steps, was 10% (13). AM-PAC IMSF (T-score >45) and Katz ADL (>5) cutoff scores identified inpatients for whom physical activity monitors initiated with a sensitivity of 94 and 91%, respectively. CONCLUSIONS: Physical capacity assessments, such as AM-PAC, and Katz ADL, may be a useful and feasible screening strategy to help identify inpatients where wearable physical activity monitors can measure their mobility.
Asunto(s)
Actividades Cotidianas , Ejercicio Físico , Adulto , Humanos , Selección de Paciente , Caminata , HospitalesRESUMEN
INTRODUCTION: Efforts to study performance fatigability have been limited because of measurement constrains. Accelerometry and advanced statistical methods may enable us to quantify performance fatigability more granularly via objective detection of performance decline. Thus, we developed the Pittsburgh Performance Fatigability Index (PPFI) using triaxial raw accelerations from wrist-worn accelerometer from two in-laboratory 400-m walks. METHODS: Sixty-three older adults from our cross-sectional study (mean age, 78 yr; 56% women; 88% White) completed fast-paced ( n = 59) and/or usual-paced 400-m walks ( n = 56) with valid accelerometer data. Participants wore ActiGraph GT3X+ accelerometers (The ActiGraph LLC, Pensacola, FL) on nondominant wrist during the walking task. Triaxial raw accelerations from accelerometers were used to compute PPFI, which quantifies percentage of area under the observed gait cadence-versus-time trajectory during a 400-m walk to a hypothetical area that would be produced if the participant sustained maximal cadence throughout the entire walk. RESULTS: Higher PPFI scores (higher score = greater fatigability) correlated with worse physical function, slower chair stands speed and gait speed, worse cardiorespiratory fitness and mobility, and lower leg peak power (| ρ | = 0.36-0.61 from fast-paced and | ρ | = 0.28-0.67 from usual-paced walks, all P < 0.05). PPFI scores from both walks remained associated with chair stands speed, gait speed, fitness, and mobility, after adjustment for sex, age, race, weight, height, and smoking status; PPFI scores from the fast-paced walk were associated with leg peak power. CONCLUSIONS: Our findings revealed that the objective PPFI is a sensitive measure of performance fatigability for older adults and can serve as a risk assessment tool or outcome measure in future studies and clinical practice.