Fewer than half (45%) of surveyed laboratories that were reporting eGFR were not reporting eGFRs >60 ml/min/1.73 m² per the NKDEP guidelines.
Chart Explanation: Fewer than half of the laboratories (45%) who reported eGFR were not reporting values >60 ml/min/1.73 m², as recommended by NKDEP due to increased imprecision and bias at these higher levels. Of the remaining laboratories, 6% were reporting up to 90 ml/min/1.73 m², 39% were reporting the exact value of eGFR, and 11% did not know their laboratory’s reporting convention. Finally, among the laboratories that did not report eGFR at the time of the survey, 59% are not considering reporting eGFR (whereas only 29% are considering eGFR reporting).
The National Kidney Disease Education Program (NKDEP) performed a survey of 6,350 representative U.S. laboratories (including physician office, hospital, independent, community clinic, health fair, insurance, public health, and other laboratories) regarding their serum creatinine and eGFR reporting practices in 2006-2007. As with any survey, there may be bias created by differential responses due to characteristics of respondents.
In the period October 2006-February 2007, the NKDEP (http://www.nkdep.nih.gov/) performed their own survey of 6,350 representative U.S. laboratories (including physician office, hospital, independent, community clinic, health fair, insurance, public health, and other laboratories) regarding their serum creatinine and eGFR reporting practices. The 10-item questionnaire included the following questions: “Does your lab report serum creatinine values for adults (18 years and older)?” (yes/no/not sure); “How many serum creatinine tests did your lab perform in 2005?”; “Does your lab ever report estimated glomerular filtration rates (eGFR) with serum creatinine determinations?”; (yes/no/not sure) “Under what circumstances does your lab report eGFR?” (with all measured serum or plasma creatinine determinations/only when specifically requested/other); “Which estimating equation do you use for your reports?” (4-parameter MDRD Study equation/6-parameter MDRD Study equation/Cockcroft-Gault/not sure/other; and “When reporting eGFR, at what point do you assign a ‘greater than’ (>) value?” (60 ml/min/1.73 m²/90 ml/min/1.73 m²/never (we always report an exact number)/other). A total of 4,002 laboratories responded to the survey (63% response rate), and 2,493 of these 4,002 laboratories responded that their laboratory reported serum creatinine and subsequently provided information on eGFR reporting.
|Description of Measure||Laboratory reporting of eGFR|
|Data Source||National Kidney Disease Education Program|
|Type of Data Source||Private|
|Data Set||Laboratory survey results|
|Health Care System Data||No|
|Regional or National?||National|
|Demographic Group||Representative sample of accredited laboratories in the CMS CLIA database with a specialty in routine chemistry testing who responded to survey|
|Numerator||Laboratories that reported eGFR with serum creatinine|
|Denominator||Representative sample of accredited laboratories that responded to survey|
|Glomerular filtration rate||Method of estimation of GFR varied by laboratory and was part of survey|
|Primary Data Source Indicator||Proportion of U.S. laboratories that reported eGFR with serum creatinine|
|Primary Indicator Method of Measurement||Survey|
|Frequency of Measurement (Primary)||Once (cross-sectional)|
|U.S. Region Covered by Primary Variable||All|
|Period Currently Available||2006–2007|
|Additional Data Items of Interest||Method of estimation, reporting standards, frequency of reporting, type of laboratory, volume of testing|
|Limitations of Indicator||Only those laboratories of the sample that responded to the survey were included; recall bias|
|Analytical Considerations||Method, standards & frequency can only be obtained within those reporting serum creatinine and eGFR|
References and Sources:
Accetta NA, Gladstone EH, DiSogra C, Wright EC, Briggs M, Narva AS. Prevalence of estimated glomerular filtration rate (eGFR) reporting among US clinical laboratories. Am J Kidney Dis. 2008;52(4):778-787.