Clinical Application of Overlapping Confidence Intervals for Monitoring Changes in Serial Clinical Chemistry Test Results

BACKGROUND: Interpretation of changes in serial laboratory results is necessary for both clinicians and laboratories; however, setting decision limits is not easy. Although the reference change value (RCV) has been widely used for auto-verification, it has limitations in clinical settings. We introduce the concept of overlapping confidence intervals (CIs) to determine whether the changes are statistically significant in clinical chemistry laboratory test results.METHODS: In total, 1,202,096 paired results for 33 analytes routinely tested in our clinical chemistry laboratory were analyzed. The distributions of delta% absolute values and cut-off values for certain percentiles were calculated. The CIs for each analyte were set based on biological variation, and data were analyzed at various confidence levels. Additionally, we analyzed the data using RCVs and compared their clinical utility.RESULTS: Most analytes had low indexes of individuality with large inter-individual variability. The 97.5th percentile cut-offs for each analyte were much larger than conventional RCVs. The percentages of results exceeding RCV(95%) and RCV(99%) corresponded to those with no overlap at the 83.4% and 93.2% confidence levels, respectively.CONCLUSIONS: The use of overlapping CIs in serial clinical chemistry test results can overcome the limitations of existing RCVs and replace them, especially for analytes with large intra-individual variation.

Performance Evaluation of Automated Chemistry Analyser for Urine Chemistry Test

BACKGROUND: Prompt and accurate urine chemistry analysis is important to provide information for diagnosis and therapy. In this study, we evaluated the overall performance and utility of an automated chemistry analyser for urine chemistry testing in accordance with Clinical and Laboratory Standards Institute guidelines. METHODS: From January 2015 to March 2015, we evaluated the precision, linearity, limits of detection, carryover, and turnaround times after automation of nine items: total protein, albumin, glucose, blood urea nitrogen, total calcium, magnesium, inorganic phosphate, creatinine, and uric acid. A Hitachi 7600-110 instrument (Hitachi Ltd., Japan) and Hitachi ID Privileged Access Manager (Hitachi Ltd.) were used for automated chemistry analysis and sample preparation, respectively. RESULTS: Regarding precision, the coefficient of variation was 3.9% to 1.6% for high levels and 3.3% to 24.1% for low levels. The linearity and coefficients of determination of all the test items were acceptable. Performance comparison revealed that the two systems were comparable, as evidenced by correlation coefficients >0.975 for most items; moreover, carryover of all items was <1%. The mean turnaround time was 59 minutes. CONCLUSIONS: Urine chemistry testing can be performed with acceptable precision, linearity, and performance by using the Hitachi 7600-110 automated chemistry analyser. The sample preparation system reduces turnaround time, which enhances the clinical utility of urine chemistry testing.

Clinical biochemistry: review and prospect / 中华检验医学杂志

With the rapid development of life science and bioinformatics,clinical biochemistry is in a period of vigorous development under the new situation of medical reform.The work of mutual recognition of test results was carried out smoothly,new guidelines for clinical applications were introduced in succession,testing technology was gradually improved.Automation,molecularization and omics study has become three trends in the development of clinical biochemistry,leading clinical biochemistry's development in an all-round way.In this article we reviewed the main events of clinical biochemistry in 2012,and look forward to witnessing that laboratory medicine will play a more important role in the diagnosis and treatment of diseases in 2013.

Economic Profile of Biochemical Tests in Rheumatic Disease / 대한류마티스학회지

Developments in science have brought about progress in automated chemistry analyzers, which have increased the capability of testing various items in short time period. This has resulted in grouping several test items into a profile. However, the profiles generally used can include some unnecessary tests for a specific patient group. Therefore, selecting the right tests for a profile of a particular patient group is a prerequisite for cost-effective medical care. The present study set out to develop an economic chemistry profile in patients suspected of having a rheumatic disease. The study included 60,302 patients who attended the Hospital for Rheumatic Diseases between June 1995 and May 2000. A total 21 different chemistry tests were performed by the automated chemistry analyzer (Hitachi-747, Hitachi Inc., Tokyo, Japan). RESULTS: A total of 758,305 chemistry tests were performed, an average of 12.6 tests per patient. The tests relatively less commonly ordered were direct bilirubin, gamma glutamyl transpeptidase, iron, TIBC. The percentage of abnormal results of total protein, albumin, total calcium, creatinine and total bilirubin were less than 5%. Therefore, these tests should be eliminated from routine testing. CONCLUSION: An economic chemistry profile for rheumatology outpatients would include alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, total cholesterol, creatine kinase, glucose, HDL-cholesterol, lactate dehydrogenase, triglyceride, uric acid. This would result in a 46.4% decrease in cost of biochemical test.