Estimated glomerular filtration rate, urine albumin excretion, and survival among patients consulting in public Chilean public primary care clinics

Abstract

Chronic renal disease (CRD) in its pre-dialysis stage is an important risk factor for mortality among adults. The aim of this study was to assess the effects of CRD on mortality among consultants in Chilean public primary care clinics. We obtained information about serum creatinine, urinary albumin excretion (UAE), blood pressure, and body mass index of 5224 consultants [3379 females aged 67 (59-75) years and 1845 males aged 68 (59-75) years] in three clinics of Metropolitan Santiago. Kaplan-Meier curves and Cox proportional hazard regression models were used to determine risk factors for mortality, determined 41 months after obtaining the blood samples. During the follow-up period, 262 patients died (33% due to circulatory causes and 29% due to tumors). Kaplan-Meier curves showed that there was a significant association between survival, estimated glomerular filtration rate, and UAE. Cox models showed that serum creatinine, UAE, a lower body mass index, and a history of diabetes were significant mortality predictors. A sensitivity analysis performed eliminating extreme ages (less than 50 and more than 80 years), included high diastolic pressure as a predictor of survival. We conclude that among patients with CRD in its pre-dialysis stage, UAE is an important predictor of survival, along with serum creatinine. A low body mass index was associated with a higher mortality.