Estimated glomerular filtration rate (eGFR) and albuminuria are among the most important cardiovascular risk factors, but the optimal cutoff for predicting mortality may not yet have been agreed upon. Foley et al. analyzed data from the population-based NHANES III study with classification tree methodology. They found that an eGFR of 94 ml/min per 1.73 m(2) and an albumin-creatinine ratio of 9 mg/g were the optimal cutoff values, that is, more 'normal' values than are used to define chronic kidney disease.