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Home > Laboratory Professionals > Estimating and Reporting GFR > Study of Estimated GFR Reporting Prevalence
Laboratory Professionals

Study of Estimated GFR Reporting Prevalence

NKDEP conducted a study in late 2006 through early 2007 to estimate the estimated glomerular filtration rate (eGFR) reporting prevalence by clinical laboratories in the United States and its territories. Previously, reporting prevalence had been known only for a few states and laboratories that participate in the College of American Pathologists’ (CAP) proficiency testing program.  (Read a summary of CAP’s 2007 survey results on eGFR reporting.)

NKDEP administered a brief survey to laboratories via mail, Internet, and telephone throughout a four-month period (view the survey instrument [PDF (130K)]). Results of the current study will serve as a baseline measure for NKDEP to assess effectiveness of efforts intended to facilitate widespread adoption of eGFR reporting. Results will also help the clinical laboratory community assess its rate of adoption of this laboratory practice.

What the Study Measured
In addition to assessing the prevalence of eGFR reporting, NKDEP sought to learn the circumstances for eGFR reporting (e.g., with every serum creatinine determination, only when requested), the most commonly used estimating equation, and at what point (or whether) laboratories begin “greater than” reporting (e.g., ≥60 mL/min/1.72 m2). NKDEP will use these data to assess the extent to which U.S. laboratories are following its recommendations.

Study Sample
The study sample was drawn from a population of more than 20,000 laboratories that conduct routine chemistry testing using the Centers for Medicare & Medicaid Services’ Clinical Laboratory Improvement Amendments (CLIA) database. The overall goal was to identify a sample that represented the broader universe of laboratories conducting this type of testing to obtain a generalizable estimate for the prevalence of eGFR reporting. 

NKDEP also sought a representative sample across laboratory types (there are 27 types in the CLIA database) to determine whether significant interlaboratory type variation exists in eGFR reporting. Related to that, the sample design took into account the relatively higher numbers of physician office, hospital, and independent laboratories; that some laboratories are more likely to run tests on blood samples from high-risk populations; and that some laboratories conduct an unusually high volume of routine chemistry tests. 

Summary of Results
NKDEP’s manuscript, Prevalence of Estimated GFR Reporting Among U.S. Clinical Laboratories, has been published in the October 2008 issue of the American Journal of Kidney Diseases.

Obtain Data Set
Researchers can obtain the study’s data set by emailing NKDEP. Please include a brief explanation of the purpose for obtaining the data set and a phone number for the investigator.

*PDF files require Adobe Acrobat

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Last Reviewed: July 18, 2008

NKDEP is an initiative of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK),
National Institutes of Health (NIH), U.S. Department of Health & Human Services (DHHS).

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