S. Eggmann1,2, M.L. Verra1, V. Stefanicki3, A. Kindler1, D. Seyler1, J.C. Schefold4, B. Zante4, C.H. Bastiaenen2
1Inselspital, Bern University Hospital, Department of Physiotherapy, Bern, Switzerland, 2Research Line Functioning and Rehabilitation CAPHRI, Maastricht University, Department of Epidemiology, Maastricht, Netherlands, 3Swiss Paraplegic Centre, Department of Physiotherapy, Nottwil, Switzerland, 4Inselspital, Bern University Hospital, University of Bern, Department of Intensive Care Medicine, Bern, Switzerland
Background: The Chelsea Critical Care Physical Assessment tool (CPAx) is a performance-based measurement for critically ill adults with excellent inter-rater reliability and established construct and cross-sectional validity. The ten items include observations of respiratory function, functional mobility and grip strength. They are rated from 0 (dependent) to 5 (independent) after a standard physiotherapy treatment.
Purpose: This study investigated the predictive validity of the CPAx score at intensive care unit (ICU) discharge in critically ill, mechanically ventilated adults. The primary hypothesis was that the score will have a moderate accuracy (AUROC=0.75) in predicting a good outcome defined as residence at home within 90 days of ICU discharge. We further hypothesised that the CPAx can discriminate between hospital discharge destinations and would moderately correlate with health-related quality of life.
Methods: A prospective clinimetric study was conducted from November, 2017 to May, 2019 in a mixed ICU of an academic hospital. Eligible participants were recruited within 72 to 144 hours of mechanical ventilation and subsequently assessed by a certified physiotherapist at baseline and ICU discharge. The main exclusion criteria were neurological admission diagnosis, wheelchair users, living in a care facility or a planned discharge on the next day. Participants were followed-up 90 days after ICU discharge to collect survival status, current residence, working status and health-related quality of life using the Short Form 36 (SF-36) questionnaire. A-priori hypotheses were investigated with ROC-analysis, non-parametric Jonckheere-Trend-Test and Spearman correlation. Prospective sample size calculation was performed.
Results: CPAx data of 58 participants (70.7% male) with a median age of 68 years (IQR 56-73), APACHE II score of 32 (IQR 28-36) and ICU stay of 7.97 days (IQR 6.69-12.85) were analysed. The CPAx scores were 5/50 (IQR 3-7) at baseline and 19/50 (IQR 14-26) at ICU discharge. The CPAx at ICU discharge performed as hypothesised with a moderate accuracy (AUROC=0.778) of predicting a return to home within 90 days. The score was further able to differentiate between hospital discharge destinations with a significant increasing trend for the following discharge groups: ‘transferred/died’ ≤ ‘rehabilitation’ ≤ ‘home’ (p<0.001). However, the correlations for the CPAx at ICU discharge with the SF-36 sum-scores at 90-day follow-up were lower than expected (physical sum-score: r=0.261, mental sum-score r=0.193).
Conclusion(s): The CPAx score at ICU discharge had a good predictive validity in predicting residence at home within 90 days as well as the general discharge destination (home, rehabilitation, transfer/death). In contrast, the CPAx does not seem useful to predict health-related quality of life.
Implications: This study expands the clinimetric properties of the CPAx. A score of >17/50 at ICU discharge has a sensitivity of 80% and specificity of 70% in predicting a good outcome of returning home after 90 days. The CPAx can therefore be partially recommended to predict patient-relevant outcomes such as discharge destination or future residence. Physiotherapists may further use the CPAx at ICU discharge to identify candidates for a targeted, in-hospital rehabilitation, to advice patients on their probable trajectory of recovery or to recognise candidates for multidisciplinary follow-up after ICU discharge.
Funding, acknowledgements: Funded with a PhD Grant 2018 from the Swiss Foundation for Physiotherapy Science and a research grant from physioswiss.
Keywords: predictive validity, measurement instrument, physical function
Topic: Critical care
Did this work require ethics approval? Yes
Institution: Inselspital, Bern University Hospital, Bern, Switzerland
Committee: Ethics Committee of Bern, Switzerland
Ethics number: ID 2017-01396
All authors, affiliations and abstracts have been published as submitted.
