The relevance of geriatric assessments on the association between chronic kidney disease stages and mortality among older people: a secondary analysis of a multicentre cohort study
Authors: Corsonello Andrea , Soraci Luca , Ärnlöv Johan , Carlsson Axel C , Roller-Wirnsberger Regina , Wirnsberger Gerhard , Mattace-Raso Francesco , Tap Lisanne , Formiga Francesc , Moreno-González Rafael , Kostka Tomasz , Guligowska Agnieszka , Artzi-Medvedik Rada , Melzer Itshak , Weingart Christian , Sieber Cornell , Lattanzio Fabrizia ,   the Screening for CKD among Older People across Europe (SCOPE) study investigators, Lattanzio Fabrizia , Corsonello Andrea , Bustacchini Silvia , Bolognini Silvia , D’Ascoli Paola , Moresi Raffaella , Di Stefano Giuseppina , Giammarchi Cinzia , Bonfigli Anna Rita , Galeazzi Roberta , Lenci Federica , Bella Stefano Della , Bordoni Enrico , Provinciali Mauro , Giacconi Robertina , Giuli Cinzia , Postacchini Demetrio , Garasto Sabrina , Cozza Annalisa , Guarasci Francesco , D’Alia Sonia , Firmani Romano , Nacciariti Moreno , Di Rosa Mirko , Fabbietti Paolo , Wirnsberger Gerhard Hubert , Roller-Wirnsberger Regina Elisabeth , Herzog Carolin , Lindner Sonja , Mattace-Raso Francesco , Tap Lisanne , Ziere Gijsbertus , Goudzwaard Jeannette , Kostka Tomasz , Guligowska Agnieszka , Kroc Łukasz , Sołtysik Bartłomiej K , Pigłowska Małgorzata , Wójcik Agnieszka , Chrząstek Zuzanna , Sosowska Natalia , Telążka Anna , Kostka Joanna , Fife Elizaveta , Smyj Katarzyna , Zel Kinga , Artzi-Medvedik Rada , Melzer Yehudit , Clarfield Mark , Melzer Itshak , Yehoshua Ilan , Melzer Yehudit , Formiga Francesc , Moreno-González Rafael , Corbella Xavier , Martínez Yurema , Polo Carolina , Cruzado Josep Maria , Gregorio Pedro Gil , Martínez Sara Laínez , Alonso Mónica González , Herrero Calvo Jose A , Molina Fernando Tornero , Fuentes Lara Guardado , García Pamela Carrillo , Pérez María Mombiedro , Renz Alexandra , Muck Susanne , Theobaldy Stephan , Bekmann Andreas , Kaltsa Revekka , Britting Sabine , Kob Robert , Weingart Christian , Freiberger Ellen , Sieber Cornel , Ärnlöv Johan , Carlsson Axel , Feldreich Tobias 
Published: July 2022

Abstract

Background
age-adapted definition of chronic kidney disease (CKD) does not take individual risk factors into account. We aimed at investigating whether functional impairments influence CKD stage at which mortality increases among older people.

Methods
our series consisted of 2,372 outpatients aged 75 years or more enrolled in a multicentre international prospective cohort study. The study outcome was 24-month mortality. Kidney function was assessed by estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR). Geriatric assessments included handgrip strength, short physical performance battery (SPPB), cognitive impairment, dependency in basic activities of daily living (BADL) and risk of malnutrition. Analysis was carried out by Cox regression, before and after stratification by individual functional impairments. Survival trees including kidney function and functional impairments were also investigated, and their predictivity assessed by C-index.

Results
overall, mortality was found to increase starting from eGFR = 30–44.9 ml/min/1.73 m2 (hazard ratio [HR] = 3.28, 95% confidence interval [CI] = 1.81–5.95) to ACR = 30–300 mg/g (HR = 1.96, 95%CI = 1.23–3.10). However, in survival trees, an increased risk of mortality was observed among patients with impaired handgrip and eGFR = 45–59.9 ml/min/1.73 m2, as well as patients with ACR &lt; 30 mg/g and impaired handgrip and SPPB. Survival tree leaf node membership had greater predictive accuracy (C-index = 0.81, 95%CI = 0.78–0.84 for the eGFR survival tree and C-index = 0.77, 95%CI = 0.71–0.81 for the ACR survival tree) in comparison with that of individual measures of kidney function.

Conclusions
physical performance helps to identify a proportion of patients at an increased risk of mortality despite a mild–moderate impairment in kidney function and improves predictive accuracy of individual measures of kidney function.