BACKGROUND: The prevalence of chronic kidney disease (CKD) is high, especially among older patients.METHODS: In order to identify risk factors for the evolution towards end-stage renal disease (ESRD), a cohort of patients ≥50 years of age for whom at least four serum creatinine measurements were available were selected from a primary care-based database. The slope of changes in estimated glomerular filtration rate (eGFR) (using the Modification of Diet in Renal Disease formula) was calculated, and ESRD was defined as eGFR <15 mL/min. Risk factors for ESRD were analysed using Cox regression analysis.RESULTS: The cohort included 24 682 patients (13 305 women) with a mean age at first available measurement of 64 years. During follow-up (average 7.8 years), 212 patients (0.9%) developed ESRD. The incidence of ESRD per 10 000 person-years is low and depends on baseline eGFR (Stages 0-2: 3, Stage 3A: 13, Stage 3B: 121 and Stage 4: 765). Adjusted hazard ratios (HRs) for patients with baseline eGFR in Stage 3B or 4 depended on age (HR = 0.47 or 0.41 for patients 65-79 years and HR = 0.26 or 0.32 for patients ≥80 years compared with patients aged 50-64 years). Females (HR = 1.48) and patients with diabetes (HR = 1.20), hypertension (HR = 1.25), high total cholesterol (HR = 1.28) or high low-density lipoprotein (LDL) cholesterol (HR = 1.39) were at higher risk for ESRD.CONCLUSIONS: Baseline eGFR, diabetes, high cholesterol, high LDL, hypertension and female gender are independent risk factors for developing ESRD. Older age at baseline predicts a lower risk.