[Correlation and concordance between the primary glomerular filtration MDRD-6 and creatinine clearance by the conventional method]

Rev Med Inst Mex Seguro Soc. Mar-Apr 2018;56(2):148-153.
[Article in Spanish]

Abstract

Background: The aim of the study was to determine the correlation and concordance between the primary glomerular filtration rate estimated by the MDRD-6 (Modification of Diet in Renal Disease, (mL/min/1.73 m2) equation and the creatinine clearance in 24-hour urine (DCr.mL/min) by conventional method.

Methods: Retrospective, observational and comparative study. We studied 180 patients, were quantified in serum: creatinine (Cr), urea nitrogen (BUN) albumin (Alb) and, in urine for 24 hours: creatinine (Cr). The calculation of the primary glomerular filtration was made with the equation MDRD-6 (mL/min/1.73 m2) and for the creatinine clearance in urine and 24 hours the equation of the conventional method (mL/min). The comparison of methods was calculated with the correlation coefficient of Person and the agreement with the unweighted Kappa test using the Landis and Koch classification.

Results: The correlation obtained between both methods was r2 = 0.4238 with a value p = < 0.0001, the strength of agreement between both Kappa methods = 0.1631.

Conclusions: The primary glomerular filtration estimated by the MDRD-6 equation (mL/min/1.73 m2) and the creatinine clearance in urine of 24 hours estimated by the conventional method equation (mL/min) have a poor correlation and poor agreement.

Introducción: el objetivo del presente trabajo fue determinar la correlación y concordancia entre el filtrado glomerular primario estimado por la ecuación MDRD-6 (Modification of Diet in Renal Disease, mL/min/1.73 m2) y la depuración de creatinina en orina de 24 horas (DCr.mL/min) por método convencional.

Métodos: estudio retrospectivo, observacional y comparativo. Se estudiaron 180 pacientes, se les cuantificó en suero: creatinina (Cr), nitrógeno de urea (BUN) y albumina (Alb), y en orina de 24 horas: creatinina (Cr). El cálculo del filtrado glomerular primario se realizó con la ecuación MDRD-6 (mL/min/1.73 m2), y para la depuración de creatinina en orina en 24 horas la ecuación del método convencional (mL/min). La comparación de métodos se calculó con el coeficiente de correlación de Person y la concordancia con la prueba de Kappa no ponderada, utilizando la clasificación de Landis y Koch.

Resultados: la correlación obtenida entre ambos métodos fue de r2 = 0.4238 con un valor p = < 0.0001, la fuerza de concordancia entre ambos métodos de Kappa = 0.1631.

Conclusiones: el filtrado glomerular primario estimado por la ecuación MDRD-6 (mL/min/1.73 m2) y la depuración de creatinina en orina de 24 horas estimada por la ecuación del método convencional (mL/min) guardan una pobre correlación y escasa concordancia.

Keywords: Renal Insufficiency, Chronic; Glomerular Filtration Rate; Creatinine.

Publication types

  • Comparative Study
  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers / urine
  • Creatinine / urine*
  • Female
  • Glomerular Filtration Rate*
  • Humans
  • Male
  • Middle Aged
  • Renal Insufficiency, Chronic / diagnosis*
  • Renal Insufficiency, Chronic / urine
  • Retrospective Studies
  • Severity of Illness Index*

Substances

  • Biomarkers
  • Creatinine