Measurement of inpatient mobility impairment can help predict later mortality

Patients who were mobile at admission and developed impairment were significantly more likely to die during the next six months, while those who recovered mobility during hospitalization had a reduced mortality risk.

A scale used to measure inpatients' mobility status identified a group of patients with a higher risk of mortality in the six months after discharge, according to a recent study.

The retrospective cohort study used data on 19,769 patients who were age 65 years or older and hospitalized at one academic center between January 2009 and April 2014. Nurses at the hospital used the Braden Activity subscale to assess mobility at every shift change (about three times per day). Scores on the scale range from 1 (patient is confined to bed) to 4 (patient walks outside the room at least twice a day and inside the room at least once every two hours during waking hours). Researchers considered a score less than 3 as significant mobility impairment. Results were published in the June Journal of Hospital Medicine.

Of the 10,717 study patients with a score of 4 at admission, 20.7% developed mobility impairment during hospitalization. The patients who developed mobility impairment had higher odds of death during follow-up than those who stayed mobile (odds ratio [OR], 1.23; 95% CI, 1.08 to 1.39), with the effect being most prominent in the first six months of follow-up. Of the 9,052 patients who were admitted with some mobility impairment, 52.3% recovered to walking occasionally or frequently by discharge. Those who recovered mobility had lower risk of death during follow-up than those who didn't (OR, 0.54; 95% CI, 0.49 to 0.59), with the effect being slightly stronger during the first six months.

The study authors concluded that the nurses' mobility assessments had “substantial prognostic value.” The study also shows that developing mobility impairment in the hospital is a sign of significant and rapid health decline and that clinicians should intervene early to try to prevent impairment and enhance mobility recovery to reduce the risk of death. The study was limited by the pooling of scores and use of data from a single center, but it shows the Braden Activity subscale could be an efficient and valuable source of information for targeting care for older adults during and after hospitalization, according to the authors.

An accompanying editorial noted that there are many scores available for measuring mobility but that none of them were designed for hospitalized patients. Ideal assessment tools are needed, but so are additional measurement methods, according to the editorialists. “Complementing the use of these tools with more objective and precise mobility measures (eg, activity counts or steps from wearable sensors) would greatly increase the ability to accurately assess mobility and potentially enable providers to recommend specific mobility goals for patients in the form of steps or minutes of activity per day,” they wrote.