Agreement between Chronic Kidney Disease Epidemiological Collaboration and Berlin Initiative Study equations for estimating glomerular filtration rate in older people: The Invecchiare in Chianti (Aging in Chianti Region) study

Abstract

Aim The aim was to investigate to what extent chronic kidney disease (CKD) can be staged interchangeably by Chronic Kidney Disease Epidemiological Collaboration (CKD-EPI) and by Berlin Initiative Study (BIS) equations, and to verify whether cystatin C can improve concordance between formulas. Methods Our series consisted of 828 community-dwelling individuals aged 65 years or older enrolled in the Invecchiare in Chianti Study (“Aging in the Chianti Region”). Estimated glomerular filtration rate was calculated using the creatinine-based CKD-EPI, creatinine/cystatin C-based CKD-EPI, creatinine-based BIS and creatinine/cystatin C-based BIS equations. Agreement and sources of discrepancy between equations in identifying people with different degrees of kidney dysfunction was investigated by κ statistic and Bland–Altman plots. Results Overall, CKD-EPI values were higher than that obtained with BIS equations, especially for eGFR = 30–60 mL/min/1.73 m2. A total of 191 out of 828 participants were classified in stage 2 by the creatinine-based CKD-EPI and in stage 3a by the creatinine-based BIS equation, whereas 123 participants were classified in stage 2 by creatinine/cystatin C-based CKD-EPI and in stage 3a by the creatinine/cystatin C-based BIS equation. A total of 27 participants were classified in stage 3a by creatinine-based CKD-EPI and in stage 3b by creatinine-based BIS equation, whereas 18 were classified as stage 3a by creatinine/cystatin C-based CKD-EPI and stage 3b by the creatinine/cystatin C-based BIS equation. Conclusions Despite a fair overall concordance, the CKD-EPI and BIS equations cannot be considered interchangeable to assess estimated glomerular filtration rate in older people, and using creatinine/cystatin C-based rather than creatinine-based equations only marginally improves the concordance between CKD-EPI and BIS. Disagreement between equations might significantly impact the applications of stage-specific measures for managing CKD among older people.

Analysis of chronic kidney disease staging with different estimated glomerular filtration rate equations in Chinese centenarians

“…The diagnosis of these CKD stages is very important for determining the specific diagnostic and therapeutic measures to be recommended. [ 9 ] These findings were similar to those of a previous study reported by Corsonello et al [ 10 ] involving elderly individuals approximately 80 years old. The CKD-EPI equation classified more patients with CKD stage 5 than the BIS1 equation.…”

Clinical Implications of Estimating Glomerular Filtration Rate with Three Different Equations among Older People. Preliminary Results of the Project “Screening for Chronic Kidney Disease among Older People across Europe (SCOPE)”

“…Several studies reported on discrepancies between eGFR values obtained with different equations, but only a few of them included the most recently published BIS and FAS equations at the same time. A former study showed that the average difference between creatinine-based CKD-EPI and BIS was 9.5 mL/min/1.73 m 2 in a population of 828 community-dwelling older people [16], which is very close to the 8.97 mL/min/1.73 m 2 difference observed in the present study. The average 8.72 mL/min/1.73 m 2 difference between CKD-EPI and FAS, as well as the negligible average difference between BIS and FAS are not surprising given the fact that FAS has been designed to match the BIS equation for ages >70 years [11].…”

“…Other biomarkers of kidney function, especially cystatin C, were investigated in an attempt to improve the accuracy of kidney function estimates. While the accuracy of equations including both creatinine and cystatin C in predicting measured GFR was found to be better than that observed with creatinine-based ones among older patients [15], the agreement between equations was found to be only marginally improved [16] and prognostic accuracy unchanged when adding cystatin C [17]. Thus, the additional costs generated by cystatin C assessment may not be associated with a true improvement in clinical assessment of kidney function.…”

The practicality of different eGFR equations in centenarians and near-centenarians: which equation should we choose?

“…In groups stratified by sex ( Fig. 4), differences in these three equations were higher in female participants than in male participants, consistent with the findings of a previous study (Corsonello et al, 2017). Notably, the eGFR tended to be overestimated when these three equations were used in women.…”

“…Notably, the selection of older adults for diagnostic and therapeutic interventions related to CKD stage changes depends on which equation is used (Changjie et al, 2017). Thus, considering the discordance among these equations with regard to their respective accuracies for predicting measured GFR has practical clinical implications (Corsonello et al, 2017). Centenarians represent a unique population in experimental research because they develop all the signs and characteristics of the extreme aging process (Puca et al, 2017).…”