Early Mobility Index and Patient Outcomes: A Retrospective Study in Multiple Intensive Care Units

Abstract

Background Early mobility interventions in intensive care units (ICUs) are safe and improve outcomes in subsets of critically ill adults. However, implementation varies, and the optimal mobility dose remains unclear. Objective To test for associations between daily dose of out-of-bed mobility and patient outcomes in different ICUs. Methods In this retrospective cohort study of electronic records from 7 adult ICUs in an academic quarternary hospital, multivariable linear regression was used to examine the effects of out-of-bed events per mobility-eligible day on mechanical ventilation duration and length of ICU and hospital stays. Results In total, 8609 adults hospitalized in ICUs from 2015 through 2018 were included. Patients were mobilized out of bed on 46.5% of ICU days and were eligible for mobility interventions on a median (IQR) of 2.0 (1–3) of 2.7 (2–9) ICU days. Median (IQR) out-of-bed events per mobility-eligible day were 0.5 (0–1.2) among all patients. For every unit increase in out-of-bed events per mobility-eligible day before extubation, mechanical ventilation duration decreased by 10% (adjusted coefficient [95% CI], −0.10 [−0.18 to −0.01]). Daily mobility increased ICU stays by 4% (adjusted coefficient [95% CI], 0.04 [0.03–0.06]) and decreased hospital stays by 5% (adjusted coefficient [95% CI], −0.05 [−0.07 to −0.03]). Effect sizes differed among ICUs. Conclusions More daily out-of-bed mobility for ICU patients was associated with shorter mechanical ventilation duration and hospital stays, suggesting a dose-response relationship between daily mobility and patient outcomes. However, relationships differed across ICU subpopulations.