Glomerular filtration rate estimation in people older than 85: Comparison between CKD-EPI, MDRD-IDMS and BIS1 equations. / Estimación del filtrado glomerular en personas mayores de 85 años: comparación de las ecuaciones CKD-EPI, MDRD-IDMS y BIS1.

BACKGROUND: The evidence of glomerular filtration rate (GFR) estimating with serum creatinine based formulae in the elderly population is scarce. The purpose of this study is to compare CKD-EPI, MRD4-IDMS and BIS1 equations to analyse correlation and concordance in a population older than 85 years old. PATIENTS AND METHODS: We designed a retrospective cross-sectional study, which included data from 600 patients older than 85 years. GFR was estimated by the following equations: CKD-EPI, MDR4-IDMS and BIS1, using as variables sex, age and serum creatinine concentration. Statistics analysis included Wilcoxon test, Bland-Altman plot, non-parametric Passing-Bablok method and kappa statistic (simple and weighted). RESULTS: The patients' median (range) age was 87 (interval 85-98). The median GFR (range) was 42.4 (5.2-127.4) mL/min/1.73 m2, when it was estimated with MDRD-IDMS, 40.0 (4.5-93.1) for CKD-EPI and 36.9 (7.6-83.7) for BIS1. The comparison of BIS1 and CKD-EPI and MDRD-IDMS using the Wilcoxon test was significant (P<.001). The regression analysis yielded the following equations: MDRD-IDMS= 1,025×CKD-EPI+1.360; BIS1= 0.688×CKD-EPI+9.074 and BIS1= 0.666×MDRD-IDMS+8.401. The weighted coefficient was 0.958 for the concordance between MDRD-IDMS and CKD-EPI, 0.812 for the concordance between MDRD-IDMS and BIS1 and 0.846 for CKD-EPI and BIS1. CONCLUSIONS: The GFR estimations obtained with BS1 equation are not interchangeable with MDRD-IDMS or CKD-EPI equations. BIS1 estimates lower GFR values than MDRD-IDMS and CKD-EPI and tends to classify the patients in a more advanced chronic kidney disease stage, especially for estimated GFR higher than 29mL/min/1.73 m2.

Estimación del filtrado glomerular en personas mayores de 85 años: comparación de las ecuaciones CKD-EPI, MDRD-IDMS y BIS1 / Glomerular filtration rate estimation in people older than 85: Comparison between CKD-EPI, MDRD-IDMS and BIS1 equations

Antecedentes: La estimación del filtrado glomerular (FG) en el anciano con las fórmulas basadas en la creatinina es limitada. El objetivo del estudio es comparar las ecuaciones CKD-EPI, MDRD-IDMS y BIS1 y analizar la correlación y la concordancia en una población mayor de 85 años. Pacientes y métodos: Realizamos un estudio transversal retrospectivo y se recogieron datos de 600 pacientes mayores de 85 años. Se estimó el FG por las ecuaciones CKD-EPI, MDRD-IDMS y BIS1 a partir de datos de sexo, edad y creatinina. El estudio estadístico incluyó el test de Wilcoxon, análisis de Bland-Altman, rectas de regresión de Passing-Bablok, concordancia bruta e índice ponderado. Resultados: La mediana (intervalo) de edad de los pacientes fue 87 (85-98). Las medianas del filtrado glomerular estimado por MDRD-IDMS fueron 42,4 (5,2-127,4) mL/min/1,73 m2, según CKD-EPI 40,0 (4,5-93,1) mL/min/1,73 m2 y por BIS1 36,9 (7,6-83,7) mL/min/1,73 m2. La comparación mediante test de Wilcoxon de BIS1 con CKD-EPI y MDRD-IDMS fue significativa (p<0,001). El análisis de regresión dio lugar a las siguientes ecuaciones: MDRD-IDMS = 1,025×CKD-EPI+1,36; BIS1=0,688×CKD-EPI+9,074 y BIS1=0,666×MDRD-IDMS+8,401. La concordancia ponderada entre MDRD-IDMS y CKD-EPI fue κ=0,598; entre MDRD-IDMS y BIS1: κ=0,812 y entre CKD-EPI y BIS1: κ=0,846. Conclusiones: Las estimaciones de FG obtenidas con la ecuación BIS1 no son intercambiables ni con MDRD-IDMS ni con CKD-EPI. La ecuación BIS1 presenta valores más bajos que MDRD-IDMS y CKD-EPI, y tiende a clasificar en un estadio mayor de ERC a los pacientes, sobre todo a partir de un FG estimado de 29mL/min/1,73 m2 (AU)

Background: The evidence of glomerular filtration rate (GFR) estimating with serum creatinine based formulae in the elderly population is scarce. The purpose of this study is to compare CKD-EPI, MRD4-IDMS and BIS1 equations to analyse correlation and concordance in a population older than 85 years old. Patients and methods: We designed a retrospective cross-sectional study, which included data from 600 patients older than 85 years. GFR was estimated by the following equations: CKD-EPI, MDR4-IDMS and BIS1, using as variables sex, age and serum creatinine concentration. Statistics analysis included Wilcoxon test, Bland-Altman plot, non-parametric Passing-Bablok method and kappa statistic (simple and weighted). Results: The patients’ median (range) age was 87 (interval 85-98). The median GFR (range) was 42.4 (5.2-127.4) mL/min/1.73 m2, when it was estimated with MDRD-IDMS, 40.0 (4.5-93.1) for CKD-EPI and 36.9 (7.6-83.7) for BIS1. The comparison of BIS1 and CKD-EPI and MDRD-IDMS using the Wilcoxon test was significant (P<.001). The regression analysis yielded the following equations: MDRD-IDMS= 1,025×CKD-EPI+1.360; BIS1= 0.688×CKD-EPI+9.074 and BIS1= 0.666×MDRD-IDMS+8.401. The weighted coefficient was 0.958 for the concordance between MDRD-IDMS and CKD-EPI, 0.812 for the concordance between MDRD-IDMS and BIS1 and 0.846 for CKD-EPI and BIS1. Conclusions: The GFR estimations obtained with BS1 equation are not interchangeable with MDRD-IDMS or CKD-EPI equations. BIS1 estimates lower GFR values than MDRD-IDMS and CKD-EPI and tends to classify the patients in a more advanced chronic kidney disease stage, especially for estimated GFR higher than 29mL/min/1.73 m2 (AU)