A decline in physical functioning is common during an intensive care unit (ICU) stay. The Functional Status Score for the Intensive Care Unit (FSS-ICU) is a performance-based measure designed to evaluate aspects of physical functioning in the ICU setting. While existing data support validity of the FSS-ICU, further investigation is needed regarding its interrater reliability.
Evaluate interrater reliability of the FSS-ICU when completed by physical therapists (PTs), as part of routine clinical practice, across a wide range of patients with critical illness.
Prospective observational evaluation.
Across patients in surgical, medical, and neurological ICUs, 8 PTs with 6 months of experience or more using the FSS-ICU (median [range] years of ICU experience = 2 [1-3]) administered the FSS-ICU. One of 2 reference rater PTs observed the FSS-ICU evaluation, and simultaneously scored it, with a minimum of 10 assessments per clinical PT. Reference rater and clinical PTs were blinded to each other's scores. Bland-Altman plots were constructed and intraclass correlation coefficients were computed using a random intercept (PT session and rater) model.
Eighty-one assessments on 76 different patients were observed by a reference rater PT. Bland-Altman plots revealed a mean difference in FSS-ICU scoring of 0.0 (95% limits of agreement: −4.0 to +4.0), with an intraclass correlation coefficient (95% confidence interval) of 0.985 (0.981-0.987). The intraclass correlation coefficients for patients in surgical, medical, and neurological ICUs were very similar: 0.984 (0.973-0.988), 0.987 (0.979-0.990), and 0.977 (0.963-0.983), respectively.
Single-center evaluation.
The FSS-ICU evaluations, performed by PTs as part of routine clinical care across a variety of patients with critical illness, have excellent reliability compared with reference rater PTs.
Stephanie Hiser, PT, DPT Department of Physical Medicine and Rehabilitation, The Johns Hopkins Hospital, Baltimore, Maryland. Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Amy Toonstra, PT, DPT, CCS Department of Physical Medicine and Rehabilitation, The Johns Hopkins Hospital, Baltimore, Maryland. Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Lisa Aronson Friedman, ScM Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Elizabeth Colantuoni, PhD Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland.
Bronwen Connolly, MSc, PhD, MCSP Guy's and St Thomas' NHS Foundation Trust and King's College London, National Institute for Health Research Biomedical Research Centre, London, United Kingdom.
Centre of Human and Aerospace Physiological Sciences, King's College London, London, United Kingdom.
Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom.
Department of Physiotherapy, The University of Melbourne, Parkville, Victoria, Australia.
Dale M. Needham, FCPA, MD, PhD Outcomes After Critical Illness and Surgery (OACIS) Group, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 1830 E. Monument St, 5th Floor, Baltimore, MD 21205 (USA). dale.needham@jhmi.edu.
S.H., A.T., E.C., and D.N. contributed to the conception and design of the study. All authors contributed to the analysis and interpretation of data. S.H. drafted the manuscript with the exception of L.F. and E.C. drafting the statistical analysis and sample size justification sections, respectively. All other authors critically revised for important intellectual content. All authors gave final approval of the manuscript version to be published.
The authors have no conflicts of interest and no source of funding to declare.
