An Empirical Study of the Clinically Reportable Range in Clinical Chemistry

임상보고 가능범위의 실증적 연구

  • Chang, Sang-Wu (Quality Management Division, Green Cross Reference Laboratories) ;
  • Lee, Sang-Gon (Clinical Chemistry Departmentt, Green Cross Reference Laboratories) ;
  • Choi, Ho-Seong (Laboratory Division, Green Cross Reference Laboratories) ;
  • Song, Eun-Young (Quality Management Division, Green Cross Reference Laboratories) ;
  • Park, Yong-Won (Clinical Chemistry Departmentt, Green Cross Reference Laboratories) ;
  • Lee, In-Ae (Clinical Chemistry Departmentt, Green Cross Reference Laboratories)
  • 장상우 (녹십자의료재단, 품질관리부) ;
  • 이상곤 (녹십자의료재단, 화학혈액 검사실) ;
  • 최호성 (녹십자의료재단, 검사부) ;
  • 송은영 (녹십자의료재단, 품질관리부) ;
  • 박용원 (녹십자의료재단, 화학혈액 검사실) ;
  • 이인애 (녹십자의료재단, 화학혈액 검사실)
  • Published : 2007.04.30

Abstract

The purpose of the clinically reportable range (CRR) in clinical chemistry is to estimate linearity in working range. The reportable range includes all results that may be reliably reported, and embraces two types of ranges: the analytical measurement range (AMR) is the range of analyte values that a method can directly measure on the specimen without any dilution, concentration, or other pretreatment not part of the usual assay process. CAP and JCAHO require linearity on analyzers every six months. The clinically reportable range is the range of analyte values that a method can measure, allowing for specimen dilution, concentration, or other pretreatment used to extend the direct analytical measurement range. The AMR cannot exceed the manufacturer's limits. Establishing AMR is easily accomplished with Calibration Verification Assessment and experimental Linearity. For example: The manufacturer states that the limits of the AST on their instrument are 0-1100. The lowest level that could be verified is 2. The upper level is 1241. The verified AMR of the instrument is 2-1241. The lower limit of the range is 2, because that is the lowest level that could be verified by the laboratory. The laboratory could not use the manufacturer's lower limit of 2 because they have not proven that the instrument values below 2 are valid. The upper limit of the range is 1241, because although the lab has shown that the instrument is linear to 1241, the manufacturer does not make that claim. The laboratory needs to demonstrate the accuracy and precision of the analyzer, as well the validation of the patient AMR. Linearity requirements have been eliminated from the CLIA regulations and from the CAP inspection criteria, however, many inspectors continue to feel that linearity studies are a part of good lab practice and should be encouraged. If a lab chooses to continue linearity studies, these studies must fully comply with the calibration/calibration verification requirements of CLIA and/or CAP. The results of lower limit and upper limit of clinically reportable range were total protein (2.1 - 79.9), albumin (1.3 - 39), total bilirubin (0.2 - 106.2), alkaline phosphatase (13 - 6928.2), aspartate aminotransferase (24 - 7446), alanine aminotransferase (13 - 6724.2), gamma glutamyl transpeptidase (16.64 - 9904.2), creatine kinase (15.26 - 4723.8), lactate dehydrogenase (127.66 - 13231.8), creatinine (0.4 - 129.6), blood urea nitrogen (8.67 - 925.8), uric acid (1.6 - 151.2), total cholesterol (48.52 - 3162), triglycerides (36.91 - 3367.8), glucose (31 - 4218), amylase (21 - 6694.2), calcium (3.1 - 118.2), inorganic phosphorus (1.11 - 108), HDL (11.74 - 666), NA (58.3 - 1800), K (1.0 - 69.6), CL (38 - 1230).

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