Development and applicability of a risk assessment tool for hospital-acquired mobility impairment in ambulatory older adults.

ABSTRACT

BACKGROUND: Mobility loss is common in hospitalized older adults, and resources to prevent mobility impairment are finite. Our goal was to use routinely collected data to develop a risk assessment tool that identifies individuals at risk of losing the ability to walk during hospitalization on the first hospital day. Second, we determined if the tool could inform the use of mobility-preserving interventions. METHODS: We included patients admitted to a general medical service, aged ≥65 years, who walked occasionally or frequently on admission (Braden Scale Activity subset > = 3). Patients were considered to have a new mobility impairment if, at discharge, their ability to walk was severely limited or nonexistent or they were confined to bed (Braden Scale Activity subset <3). We used predictors available on the first hospital day to develop (2017-18 cohort) and validate (2019 cohort) a risk assessment tool. We determined the association between predicted risk and therapy use in the validation cohort to highlight the model's clinical utility. RESULTS: 5542 patients were included (median age 76 years, 48% women); 7.6% were discharged unable to walk. The model included 5 predictors age, medication administrations, Glasgow Coma Scale verbal score, serum albumin, and urinary catheter presence. In the validation cohort, the model discriminated well (c-statistic 0.75) and was strongly associated with hospital-acquired mobility impairment (lowest decile 1%, highest decile 25%). In the validation cohort, therapy consultation ordering increased linearly with predicted risk; however, observed mobility impairment increased exponentially. CONCLUSION: The tool assesses the risk of mobility impairment in all ambulatory hospitalized older adults on the first hospital day. Further, it identifies at-risk older adults who may benefit from mobility interventions.