Utility of Functional Metrics Assessed During Acute Care on Hospital Outcomes: A Systematic Review

Abstract

Objective: Traditionally, illness severity, social factors, and comorbid conditions have been examined as predictors of hospital outcomes. However, recent research in the rehabilitation setting demonstrated that physical function outperformed comorbidity indices as a predictor of 30-day readmission. The purpose of this study was to review the literature examining the association between acute hospital physical function and various hospital outcomes and health care utilization. TYPE: Systematic review.

Literature survey: A review of the MEDLINE database was performed. Search terms included acute functional outcomes and frailty outcomes. Studies up to September 2017 were included if they were in English and examined how functional metrics collected at acute care hospitalization affected hospital outcomes.

Methodology: Cohort characteristics and measures of associations were extracted from the studies. Outcomes include hospital readmission, length of stay, mortality, discharge location, and physical function post acute care. The studies were assessed for potential confounders as well as selection, attrition, and detection bias.

Synthesis: A total of 30 studies were identified (hospital readmissions: 6; discharge location: 11; length of stay: 4; mortality: 15; function: 6). Thirteen different metrics assessed function during acute care. Lower function during acute care was associated with statistically significant higher odds of hospital readmission, lower likelihood of discharge to home, longer hospital length of stay, increased mortality, and worse functional recovery when compared to patients with higher function during acute care, when adjusted for age and gender. The Barthel Index may be a useful marker for mortality in the elderly whereas the Functional Independence Measure instrument may be valuable for examining discharge location.

Conclusions: There is increasing evidence that function measured during acute care predicts a broad array of meaningful clinical outcomes. Further research would help direct the use of practical, yet parsimonious functional metrics that effectively screen high-need, high-cost patients to deliver optimal care.

Level of evidence: I.

Figure 1.

Functional metrics measured in the acute care setting. SPPB = short physical performance battery; FIM = Functional Independence Measure; ADL = activities of daily living.

Figure 2.

Association between lower function and various measures of associations. RR = relative risk. All reported measures of associations are from the original manuscripts without independent statistical analysis or calculations.