The Predictive Validity of Functional Outcome Measures With Discharge Destination for Hospitalized Medical Patients

OBJECTIVE: To investigate the predictive validity for discharge to home or facility of 4 functional mobility outcome measures. DESIGN: Retrospective, observational study. SETTING: Urban, academic hospital in the United States. PARTICIPANTS: Adult patients (N=3999) admitted to medical units between June 1, 2019, and February 29, 2020, with 2 or more recorded scores on each of 4 tools: Activity Measure for Post-Acute Care (AM-PAC) 6-Clicks Basic Mobility and Daily Activity, Henry Ford Mobility Level, and The Johns Hopkins Highest Level of Mobility. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Mobility scores and discharge destination. RESULTS: For the 3999 subjects, 51.4% went home at discharge and had higher mean scores on each measure than those not returning home. Both early (I) and later (II) time point for each measure had positive predictability for discharge home. AM-PAC 6-Clicks had the highest confidence intervals for early and later recorded scores. The c-statistic value for Basic Mobility I (cut point=16) was 0.74 and for II (cut point=18) was, 0.79. The value for Daily Activity I (cut point=18) was 0.75 and for Daily Activity II (cut point=18) was 0.80). The Johns Hopkins Highest Level of Mobility and Henry Ford Mobility Level measures were less discriminative at initial score (c-statistic 0.704 and 0.665, respectively) and final score (c-statistic 0.74 and 0.75, respectively). CONCLUSIONS: Functional outcome measures have good predictive validity for discharge destination. The AM-PAC Basic mobility score appears to have a slightly higher confidence interval than the other tools in this study design.