Clinical and Prognostic Implications of Estimating Glomerular Filtration Rate by Three Different Creatinine-Based Equations in Older Nursing Home Residents

Ersilia Paparazzo; Silvana Geracitano; Vincenzo Lagani; Luca Soraci; Annalisa Cozza; Salvatore Cosimo; Francesco Morelli; Andrea Corsonello; Giuseppe Passarino; Alberto Montesanto

doi:10.3389/fmed.2022.870835

Clinical and Prognostic Implications of Estimating Glomerular Filtration Rate by Three Different Creatinine-Based Equations in Older Nursing Home Residents

Front Med (Lausanne). 2022 Apr 26:9:870835. doi: 10.3389/fmed.2022.870835. eCollection 2022.

Authors

Affiliations

¹ Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
² Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia.
³ Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
⁴ Unit of Geriatric Medicine, Italian National Research Center on Aging (IRCCS INRCA), Cosenza, Italy.
⁵ Laboratory of Pharmacoepidemiology and Biostatistics, Italian National Research Center on Aging (IRCCS INRCA), Cosenza, Italy.
⁶ SADEL S.p.A., Cotronei, Italy.

Abstract

Background: According to the international literature, the percentage of nursing home (NH) residents with renal insufficiency is very high, ranging between 22 and 78%. Diminished kidney function represents a risk factor for drug overdosage, adverse drug reactions, end-stage renal disease, disability, morbidity, and mortality. Several studies suggested that screening for chronic kidney disease (CKD) in high-risk and older populations may represent a cost-effective approach to reducing progression to renal failure and CKD mortality.

Objective: This study aimed (i) to investigate to what extent CKD may be staged interchangeably by three different creatinine-based estimated glomerular filtration rate (eGFR) equations in a sample of older adults living in long-term care facilities; (ii) to investigate factors explaining differences among eGFR equations; and (iii) to compare the predictivity of different creatinine-based eGFR equations with respect to all-cause mortality.

Methods: A total of 522 residents aged 65 years and older participated in a prospective cohort study of 9 long-term care facilities in Calabria. eGFR was calculated by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Berlin initiative study (BIS), and full age spectrum (FAS) equations. Disability in at least one activity of daily living (ADL), depression, cognitive impairment, comorbidity, and malnutrition was considered in the analysis. Statistical analysis was carried out by Bland-Altman analysis, and 2-year mortality was investigated by Kaplan-Meier curves and Cox regression analysis.

Results: Depending on the adopted equation, the prevalence of NH residents with impaired renal function (eGFR < 60 ml/min/1.73 m²) ranged between 58.2% for the CKD-EPI and 79.1% for the BIS1 equation. The average difference between BIS and FAS was nearly negligible (0.45 ml/min/1.73 m²), while a significant bias was detected between CKD-EPI and BIS and also between CKD-EPI and FAS (6.21 ml/min/1.73 m² and 6.65 ml/min/1.73 m², respectively). Although the eGFR study equations had comparable prognostic accuracy in terms of mortality risk, BIS and FAS were able to reclassify NH residents pertaining to a low-risk group with CKD-EPI, and this reclassification improves the discriminative capacity of CKD-EPI with respect to overall mortality.

Conclusion: Despite the relatively good correlation between eGFRs calculated using all adopted equations, the findings in this study reported clearly demonstrated that CKD-EPI and BIS/FAS equations are not interchangeable to assess eGFR among older people and particularly in institutionalized and frail older subjects.

Keywords: Berlin initiative study (BIS); chronic kidney disease (CKD); estimated glomerular filtration rate (eGFR); full age spectrum (FAS); older patients.