A systematic review of measurements of physical function in critically ill adults

Patients who recover from critical illness may be left with significant limitations to their physical function that can have important consequences for their quality of life. Measures of physical function may be useful end points to consider in studies conducted in critically ill patients and are particularly attractive in studies investigating early mobilisation and rehabilitation.

To describe measurements of physical function used in studies investigating early mobilisation and rehabilitation in critically ill adults.

A systematic search of Ovid MEDLINE, Embase, CINAHL, Cochrane Library and PEDro was undertaken to identify studies investigating early mobilisation and rehabilitation in critically ill adults. Two researchers independently extracted data from identified studies that described measurements of physical function and that evaluated the available evidence for the measurement properties and risk of bias associated with the identified end points.

We identified 11 studies of early mobilisation and rehabilitation in critically ill patients, involving 19 distinct measures of physical function. The ability to perform activities such as sitting and standing and the maximum distance ambulated were the most commonly used end points. Only one end point in the included studies, the Functional Status Score for the ICU (FSS-ICU), was designed for use in the ICU setting. Of the end points used, only the Short Form 36 (SF-36), the Medical Research Council (MRC) scale score and handheld dynamometers have proven interrater reliability and population validity in the ICU setting.

A wide range of end points have been used to evaluate physical function in critically ill patients. However, further studies are needed to establish the measurement properties of the most commonly used end points in order to recommend their use in clinical trials.