Validation of the Clinical Frailty Score (CFS) in French Language

Background: Very old critical ill patients are a rapid expanding group. To better understand the magnitude of the challenges involved in intensive care practice for an ageing population and discuss a rational allocation of resources, healthcare practitioners need a reliable evaluation of frailty. In order to promote the adequate use of the Clinical Frailty Scale (CFS) in a wider panel of countries, we aimed to develop, validate and characterise a French (FR) version from the original English (EN) CFS. Methods: We included participants recruited prospectively for the observational "The very old intensive care patient: A multinational prospective observation study" (VIP Study) at Geneva University Hospitals (FR speaking hospital). A FR version of the CFS was obtained by translation (EN- > FR) and back translation (FR- > EN). The final CFS-FR was then evaluated twice on the same participants with at least a 2-week interval by FR-speaking doctors and nurses. Results: Inter-rater reliability was 0.87 (95%CI: 0.76-0.93) between doctors for the original CFS version and 0.76 (95%CI: 0.57-0.87) between nurses for the FR version. Inter-rater variability between doctor and nurse was 0.75 (95%CI: 0.56-0.87) for the original version, and 0.73 (95%CI: 0.52-0.85) for the FR version. Test-retest (stability) with the original vs the FR version was 0.86 (95%CI: 0.72-0.93) for doctors and 0.87 (95%CI: 0.76-0.93) for nurses. Differences between the evaluations of the CFS-EN and CSF-FR were not different from 0, with a mean difference of 0.06 (95%CI -0.24, 0.36) for the EN version and - 0.03 (95%CI -0.47, 0.41) for the FR version. Average original version ratings were slightly lower than FR version ratings, though this difference did not reach significance: -0.29 (95%CI -0.54, 0.04). Conclusion: In this prospective cohort of very old intensive care participants we developed and tested the basic psychometric properties (internal consistency, reproducibility) of a French version of the CFS. This manuscript provides clinically ...