Original Research

Association Between Physiotherapy Outcome Measures and the Functional Independence Measure: A Retrospective Analysis

Journal of Clinical Outcomes Management. 2021 November;28(6):259-267 | doi:10.12788/jcom.0069

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Results

The patient descriptive data (site from which data were collected, admission length of stay, age at admission, discharge destination, walk aid improvement, and walk assistance improvement) from the 3 impairment groups are reported in Table 2. The functional outcomes for DEMMI, TUG, 10MWT, FIM Motor, FIM Total at admission, discharge, and the change scores are presented in Table 3.

Orthopedic fracture patients had the greatest improvement in their functional outcomes, with a DEMMI improvement of 18 points, TUG score change of 23.49 seconds (s), 10MWT change of 0.30 meters/second (m/s), FIM Motor change of 20.62, and a FIM Total change of 21.9 points. The outcome measures exceeded the minimum detectable change as reported in the literature for DEMMI (8.8 points⁴⁸), TUG (2.08 s²⁶), walking speed 0.19 m/s²⁶, and FIM Motor (14.6 points⁴⁹).

Association of functional outcomes (change scores)

There was a significant weak positive correlation between DEMMI change score and both the FIM Motor (r = 0.396) and FIM Total change scores (r = 0.373). When viewing the specific items within the FIM Motor labelled FIM Walk change, FIM MobilityBedChair change, and FIM stairs change, r values were 0.100, 0.379, and 0.126, respectively. In addition, there was a weak negative correlation between TUG change scores and both FIM Motor (r = -0.217) and FIM Total change scores (r = -0.207). There was a very weak positive correlation between 10MWT (m/s) change scores and both FIM Motor (r = 0.194) and FIM Total change scores (r = 0.187) (Table 4, Figure). There was a moderate correlation between 10MWT change (s) and TUG change (s) (r = 0.72, P < .001).

Discussion

The purpose of this study was to ascertain the association between the DEMMI, TUG, 10MWT, and FIM measures using retrospective data collected from 5 public hospital inpatient rehabilitation wards. The results of this retrospective analysis demonstrate that a variety of objective outcome measures are required for the multidisciplinary team to accurately measure a patient’s functional improvement during their inpatient rehabilitation stay. No single outcome measure in this study fully reported all mobility attributes, and we note the risk of basing decisions on a single measure evaluating rehabilitation outcomes. Although the internationally used FIM has a strong place in rehabilitation reporting and benchmarking, it does not predict change nor provide a proxy for the patient’s whole-body motor control as they extend their mobility, dynamic balance, and ambulatory ability. Multiple objective outcome measures should therefore be required to evaluate the patient’s progress and functional performance toward discharge planning.

The FIM is a measure of disability or care needs, incorporating cognitive, social, and physical components of disability. It is a valid, holistic measure of an individual’s functional ability at a given time. Rehabilitation sites internationally utilize this assessment tool to evaluate a patient’s progress and the efficacy of intervention. The strength of this measure is its widespread use and the inclusion of the personal activities of daily living to provide an overall evaluation encompassing all aspects of a person’s ability to function independently. However, as our study results suggest, patient improvement measured by the FIM Motor components were not correlated to other widely used physiotherapy measures of ambulation and balance, such as the 10MWT or TUG. This is perhaps largely because the FIM Motor components only consider the level of assistance (eg, physical assistance, assistive device, independence) and do not consider assessment of balance and gait ability as assessed in the 10MWT and TUG. The 10MWT and TUG provide assessment of velocity and dynamic balance during walking, which have been shown to predict an individual’s risk of falling.^22,23 This is a pertinent issue in the rehabilitation and geriatric population.²⁹ Furthermore, the use of the FIM as a benchmarking tool to compare facility efficiency may not provide a complete assessment of all outcomes achieved on the inpatient rehabilitation ward, such as reduced falls risk or improved ambulatory ability and balance.