Objective: To compare the prevalence and classification of chronic kidney disease (CKD) in accordance with the estimated glomerular filtration rate (eGFR) by MDRD-4 IDMS and CKD-EPI in individuals ≥ 60 years of age in primary care.
Material and methods: Cross-sectional descriptive observational study. Subjects ≥ 60 years treated at 40 primary care centres with serum creatinine determination conducted between 1 January and 31 December 2010 at a single centralised laboratory.
Exclusion criteria: renal transplantation, home care.
Variables: socio-demographic, anthropometric, risk factors and cardiovascular disease as recorded in electronic medical records and serum creatinine concentration by a standardised compensated kinetic Jaffe method with IDMS and eGFR by MDRD-4 IDMS and CKD-EPI. Agreement was analysed using the kappa coefficient and the Bland-Altman graphical method.
Results: 97,554 individuals (57.3% women, mean age 70.0 [Q1: 65.0, Q3: 77.0]). Median eGFR with MDRD 78.7 [66.7, 91.0] ml/min/1.73m² (77.9 for women, 79.7 for men, P<.001) and 81.8 [68.5, 90.5] ml/min/1.73 m² (P=.311) with CKD-EPI, eFG(MDRD) prevalence <60 15.0% (16.5% women, 13.1% men and 6.5% in ≤ 70 years, 24%> 70 years) with CKD-EPI 14.2% (15.0% female, 13.0% male, 4.7% in ≤ 70 years, 24.1% in> 70 years) . There was an overall agreement of 85.6% (kappa coefficient = 0.75) in women> 70 years of 86.6% (kappa = 0.77), of 83.2% (kappa = 0.69) in men> 70 years, of 82.7% (kappa = 0.68) in women ≤ 70 years and 90% (kappa = 0.81) in men ≤ 70 years.
Conclusions: CKD-EPI decreased the prevalence of CKD especially in women ≤ 70 years; the prevalence increased in men> 70 years. One in eight individuals with stage 3a was reclassified to no disease; reclassified individuals had lower comorbidity.