Epidemiology and OutcomesIdentifying Individuals with a Reduced GFR Using Ambulatory Laboratory Database SurveillanceGarg, Amit X.*,†; Mamdani, Muhammad‡,∥; Juurlink, David N.§,∥; van Walraven, Carl∥,¶,** for the Network of Eastern Ontario Medical Laboratories (NEO-MeL) Author Information *Division of Nephrology and†Department of Epidemiology and Biostatistics, University of Western Ontario, London; Departments of‡Pharmacy and§Medicine, University of Toronto, and∥Institute for Clinical Evaluative Sciences, Toronto; and Departments of¶Medicine and**Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada Address correspondence to: Dr. Amit Garg, University of Western Ontario, London Kidney Clinical Research Unit, Room A01, Westminster Tower, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 4G5, Canada. Phone: 519-685-8502; Fax: 519-685-8072; E-mail: [email protected] Received August 21, 2004. Accepted February 8, 2005. Published online ahead of print. Publication date available atwww.jasn.org. Journal of the American Society of Nephrology 16(5):p 1433-1439, May 2005. | DOI: 10.1681/ASN.2004080697 Buy Metrics Abstract The use of outpatient laboratory databases to identify people with a low GFR may be part of an effective strategy to increase their use of treatments to prevent kidney failure. All renal function data from 17 independent outpatient laboratories in Eastern Ontario were combined to determine the proportion of adults with at least one serum creatinine measurement during a 1-yr period. The detection rates of low GFR were measured using different algorithms, and what proportion of identified low GFR was transient was considered. Canadian census data were used to calculate rates and proportions. Renal function testing was common. Of the 1,090,000 adult residents, 32% of the entire population and 63% of seniors had at least one serum creatinine measured during the study year. Sixteen percent of the population (49% of those with tests performed) had at least one GFR <80 ml/min per 1.73 m2, 5% (16%) had at least one GFR <60 ml/min per 1.73 m2, and 0.6% (1.7%) had at least one GFR <30 ml/min per 1.73 m2. Low GFR were usually not transient: 68% of individuals with subsequent testing at least 30 d later had a similar or worse GFR. Ambulatory laboratory database case finding, particularly in older patients, seems to be a promising method for easily identifying large segments of the population with persistent reductions in GFR. Whether such identification leads to improved health outcomes warrants further study. Copyright © 2005 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.