Abstract
We conducted a study to characterize the variability in the upper limit of normal (ULN) for alanine aminotransferase (ALT) across different laboratories (labs) in Indiana and to understand factors leading to such variability. A survey was mailed to all eligible labs (n = 108) in Indiana, and the response rate was 62%. The survey queried for ALT ULN, the type of chemical analyzer used, five College of American Pathologists (CAP) sample results, and methods used to establish the reference interval. There was a wide variability in the ALT ULN for both men and women. Eighty-five percent of labs used chemical analyzers belonging to one of the four brands. For all five CAP samples, there was a statistically significant difference in ALT values measured by different analyzers (P<0.0001), but these differences were not clinically significant. The majority of labs used the manufacturers' recommendations for establishing their ALT ULN rather than in-house healthy volunteer testing (only 17%). When healthy volunteers were tested, the process for testing was haphazard in terms of the number of individuals tested, frequency of testing, and criteria for choosing the reference population. After controlling for chemical analyzer type, there was no significant relationship between ALT ULN values and the method used for its establishment. Conclusion: Wide variability in ALT ULN across different labs is more likely due to variable reference intervals of different chemical analyzers. It may be possible to minimize variability in ALT ULN by (1) each lab solely following the manufacturers' recommendations and (2) manufacturers of different analyzers following consistent and rigorous methodology in establishing the reference range. Alternatively, studies should be undertaken to identify outcome-based reference intervals for ALT.
| Original language | English |
|---|---|
| Pages (from-to) | 1957-1962 |
| Number of pages | 6 |
| Journal | Hepatology |
| Volume | 50 |
| Issue number | 6 |
| DOIs | |
| State | Published - 2009 |
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ASJC Scopus subject areas
- Hepatology
Cite this
Variability in the upper limit of normal for serum alanine aminotransferase levels : A statewide study. / Dutta, Anand; Saha, Chandan; Johnson, Cynthia S.; Chalasani, Naga.
In: Hepatology, Vol. 50, No. 6, 2009, p. 1957-1962.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Variability in the upper limit of normal for serum alanine aminotransferase levels
T2 - A statewide study
AU - Dutta, Anand
AU - Saha, Chandan
AU - Johnson, Cynthia S.
AU - Chalasani, Naga
PY - 2009
Y1 - 2009
N2 - We conducted a study to characterize the variability in the upper limit of normal (ULN) for alanine aminotransferase (ALT) across different laboratories (labs) in Indiana and to understand factors leading to such variability. A survey was mailed to all eligible labs (n = 108) in Indiana, and the response rate was 62%. The survey queried for ALT ULN, the type of chemical analyzer used, five College of American Pathologists (CAP) sample results, and methods used to establish the reference interval. There was a wide variability in the ALT ULN for both men and women. Eighty-five percent of labs used chemical analyzers belonging to one of the four brands. For all five CAP samples, there was a statistically significant difference in ALT values measured by different analyzers (P<0.0001), but these differences were not clinically significant. The majority of labs used the manufacturers' recommendations for establishing their ALT ULN rather than in-house healthy volunteer testing (only 17%). When healthy volunteers were tested, the process for testing was haphazard in terms of the number of individuals tested, frequency of testing, and criteria for choosing the reference population. After controlling for chemical analyzer type, there was no significant relationship between ALT ULN values and the method used for its establishment. Conclusion: Wide variability in ALT ULN across different labs is more likely due to variable reference intervals of different chemical analyzers. It may be possible to minimize variability in ALT ULN by (1) each lab solely following the manufacturers' recommendations and (2) manufacturers of different analyzers following consistent and rigorous methodology in establishing the reference range. Alternatively, studies should be undertaken to identify outcome-based reference intervals for ALT.
AB - We conducted a study to characterize the variability in the upper limit of normal (ULN) for alanine aminotransferase (ALT) across different laboratories (labs) in Indiana and to understand factors leading to such variability. A survey was mailed to all eligible labs (n = 108) in Indiana, and the response rate was 62%. The survey queried for ALT ULN, the type of chemical analyzer used, five College of American Pathologists (CAP) sample results, and methods used to establish the reference interval. There was a wide variability in the ALT ULN for both men and women. Eighty-five percent of labs used chemical analyzers belonging to one of the four brands. For all five CAP samples, there was a statistically significant difference in ALT values measured by different analyzers (P<0.0001), but these differences were not clinically significant. The majority of labs used the manufacturers' recommendations for establishing their ALT ULN rather than in-house healthy volunteer testing (only 17%). When healthy volunteers were tested, the process for testing was haphazard in terms of the number of individuals tested, frequency of testing, and criteria for choosing the reference population. After controlling for chemical analyzer type, there was no significant relationship between ALT ULN values and the method used for its establishment. Conclusion: Wide variability in ALT ULN across different labs is more likely due to variable reference intervals of different chemical analyzers. It may be possible to minimize variability in ALT ULN by (1) each lab solely following the manufacturers' recommendations and (2) manufacturers of different analyzers following consistent and rigorous methodology in establishing the reference range. Alternatively, studies should be undertaken to identify outcome-based reference intervals for ALT.
UR - http://www.scopus.com/inward/record.url?scp=73149100612&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=73149100612&partnerID=8YFLogxK
U2 - 10.1002/hep.23200
DO - 10.1002/hep.23200
M3 - Article
C2 - 19787805
AN - SCOPUS:73149100612
VL - 50
SP - 1957
EP - 1962
JO - Hepatology
JF - Hepatology
SN - 0270-9139
IS - 6
ER -