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
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.
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
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.
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