Operationalizing a frailty index using routine blood and urine tests
Authors Ritt M, Jäger J, Ritt JI, Sieber CC, Gaßmann KG
Received 9 January 2017
Accepted for publication 17 March 2017
Published 28 June 2017 Volume 2017:12 Pages 1029—1040
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 2
Editor who approved publication: Dr Richard Walker
Martin Ritt,1,2 Jakob Jäger,2 Julia Isabel Ritt,2 Cornel Christian Sieber,1,3 Karl-Günter Gaßmann1,2
1Institute for Biomedicine of Ageing (IBA), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Nuremberg, Germany; 2Department of Internal Medicine III (Medicine of Ageing), Geriatrics Center Erlangen, Hospital of the Congregation of St Francis Sisters of Vierzehnheiligen, Erlangen, Germany; 3Department of General Internal Medicine and Geriatrics, Hospital of the Order of St John of God, Regensburg, Germany
Background: Uncomplicated frailty instruments are desirable for use in a busy clinical setting. The aim of this study was to operationalize a frailty index (FI) from routine blood and urine tests, and to evaluate the properties of this FI compared to other frailty instruments.
Materials and methods: We conducted a secondary analysis of a prospective cohort study on 306 patients aged ≥65 years hospitalized on geriatric wards. An FI comprising 22 routine blood parameters and one standard urine parameter (FI-Lab), a 50-item FI based on a comprehensive geriatric assessment (FI-CGA), a combined FI (FI-combined [items from the FI-Lab + others from the FI-CGA]), the Clinical Frailty Scale, rule-based frailty definition, and frailty phenotype were operationalized from data obtained during patients’ hospital stays (ie, before discharge [baseline examination]). Follow-up data were obtained up to 1 year after the baseline examination.
Results: The mean FI-Lab score was 0.34±15, with an upper limit of 0.74. The FI-Lab was correlated with all the other frailty instruments (all P<0.001). The FI-Lab revealed an area under the receiver-operating characteristic curve (AUC) for 6-month and 1-year mortality of 0.765 (0.694–0.836) and 0.769 (0.706–0.833), respectively (all P<0.001). Each 0.01 increment in FI-Lab increased the risk (adjusted for age and sex) for 6-month and 1-year mortality by 7.2% and 7.1%, respectively (all adjusted P<0.001). When any of the other FIs (except the FI-combined) were also included in the models, each 0.01 increment in FI-Lab score was associated with an increase in the risk of 6-month and 1-year mortality by 4.1%–5.4% (all adjusted P<0.001).
Conclusion: The FI-Lab showed key characteristics of an FI. The FI-Lab can be applied as a single frailty measure or in combination with/in addition to other frailty instruments.
Keywords: older people, hospital, geriatric wards, frailty, risk stratification, mortality
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]