Prevalence of chronic kidney disease in subjects consulting in urban primary care clinics

Background: Chronic kidney disease (CKD) is a major worldwide public health problem and is associated with increased risk of cardiovascular disease and death. Aim: To assess CKD prevalence in urban Primary Care Services (PCS) of Concepcion, Chile. Material and Methods: The clinical records of 27.894 adults aged 55 +/- 18 years (66% females), consulting in outpatient clinics and in whom serum creatinine was measured, with or without assessment of urine albumin levels, were reviewed. The glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease (MDRD)-4 equation. CKD was defined as an eGFR <60 ml/min/1.73 m(2) and classified according to the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NFK-KDOQI) guidelines. Results: Mean eGFR was 77.1 +/- 16.3 ml/min/1.73 m(2). Twelve percent of subjects had CKD (women, 14.5% and men 7,4%, p < 0,05). The prevalence of stages 3, 4 and 5 of CKD were 11.6, 0.3 and 0.2 % respectively eGFR was negatively correlated with age ( r = -0,54, p < 0,05). Among patients with an eGFR <60 ml/min/1.73 m(2), 96.3% had eGFR 30-59, 2.3% 15-29 and 1.4 % < of 15. Seventy nine percent were women. 75.1% were aged 65 years or more, 26.8% had a serum creatinine equal or less than 1.0 mg/dL and 40.5% had microalbuminuria. Only 1% of outpatients ascribed to Cardiovascular or Diabetes Programs had the diagnosis of CKD registered. Independent risk predictors of CKD were age > 60 years, female sex and microalbuminuria. Conclusions: This study showed a high prevalence of CKD in ambulatory patients, mainly among women and older people. The low level of diagnosis of CKD in cardiovascular and diabetes programs is of concern. (Rev Med Chile 2011; 139: 1176-1184).