Risk of hospital-acquired disability greater at low physical activity levels

Low levels of physical activity while in the hospital appears to increase the likelihood of hospital-acquired disability (HAD) in elderly adults, a recent study has shown.

Researchers conducted a prospective, observational assessment of 46 community-dwelling elderly adults (mean age, 73.2±9.5 years; 48 percent male) who were admitted to general medicine departments. The primary outcome was the development of HAD. An ankle accelerometer was used to measure hospital activity. Assessments were performed within 24 hours of admission.

Participants wore their accelerometers for a mean of 4.1±2.0 days, for an average of 16±2.8 hours per day. Devices were worn mostly during the daytime.

Almost half (n=19; 41 percent) of the participants developed HAD, 12 of whom (26 percent) self-reported declines in activities of daily living and scores in the Late-Life Function and Disability Instrument. Seven (15 percent) were discharged to a skilled nursing facility.

Daily activity time (0.8 vs 1.4 hours; p=0.04) and step counts (1,186 vs 1,808 steps; p=0.04) were both significantly lower in participants who developed HAD. Sedentary time had no apparent effect.

Almost a quarter of the participants (24 percent; n=11) walked less than 900 steps per day; more than half of this group (64 percent; n=7) developed HAD. The corresponding risk estimate was elevated but not statistically significant (odds ratio, 3.4, 95 percent confidence intervals, 0.82–13.8). At this threshold, step count had a sensitivity of 0.4 and specificity of 0.85 for predicting HAD.

“Further studies are needed to determine if higher step count thresholds can improve the sensitivity for the identification of hospitalized populations at increased risk for functional decline during hospitalization,” said the researchers.