Pdf preanalytical variables and their influence on the quality of. Aug 28, 2009 the results of laboratory tests have a substantial role in the diagnostics of diseases. This increasing importance and awareness of preanalytical variables led to the first and now second eflmbd european federation of clinical chemistry and laboratory medicine becton dickinson conference on preanalytical phase 35,36. Factors that can affect the laboratory tests lab me. Some of the preanalytical variables such as specimen variables can be. Up to 70% of testing errors occur in the pre analytical phase1. The preanalytical phase includes a set of processes that take place from the time a laboratory request is made by a physician until the sample is ready for testing. The cost of poor blood specimen quality and errors in. The impact of preanalytical variables on the quality of laboratory results. It also shares strategies to reduce specimen recollection, based upon published data and mayo clinic experience.
The results of laboratory tests have a suhstantial role in the diagnostics of diseases. Dec 15, 2009 preanalytic variables can affect test results, leading to misinterpretation and inappropriate patient care. Preanalytical errors and their impact on tests in clinical laboratory. The preanalytical phase of the laboratory testing process includes all of the procedures prior to the start of sample analysis, and typically involves a variety of healthcare professionals. Ordering inappropriate tests is another preanalytical variable that negatively impacts patient. The national committee for clinical laboratory standards.
Article id 1200107 preanalytical phase preanalytical. The preanalytical phase encompasses all the processes from the time of a laboratory request made by the physician until the specimen is analyzed in the lab. General chemistry technical bulletin centrifugation the role. Preanalytic variables in laboratory testing laboratory medicine. In such cases the patients own previous results are a useful baseline. On the other hand, an abnormal laboratory result may be accepted as such and interpreted as a sign of a disease. Preanalytical variables in the chemistry laboratory.
Besides the many publications he has also authored a book on principles and applications of laboratory instrumentation and coauthored with prof. When blood specimens cool from body temperature to room temperature, the cryoglobulins aggregate and may be falsely identified as platelets andor wbcs by the hematology analyzer. Preanalytical factors are an important source of variation or errors in clinical laboratory measurements. Pre analytical variables account for 3275% of laboratory errors, and encompass the time from when thetest is ordered by the physician until the sample is ready for analysis. Preanalytical variables in coagulation testing associated with diagnostic errors in hemostasis. A set of books by donald young is available that cites the basic scientific literature for general effects of drugs, disease, and preanalytical variables on clinical laboratory tests. Preanalytical factors affecting the results of laboratory. Preanalytical variables account for 3275% of laboratory errors, and encompass the time from when thetest is ordered by the physician until the sample is ready for analysis. Preanalytical variables of coagulation testing elite.
Preanalytical and analytical factors affecting laboratory. For the clinical laboratory, errors that occur in the preanalytical phase of testing may account for up to 75% of total laboratory errors. This fourth, updated edition contains the latest developments in analytical techniques. The number of preanalytical factors of variation is very high as published and itemized by young reference young 2007.
The third and fourth sections are alphabetic sorts by laboratory test and by preanalytical variable, respectively. Effects of preanalytical variables on clinical laboratory tests, 3rd edition 9781594250682. Recommendations for sample collection, storage, processing and transport have been developed by national and international consensus. Overall, a significant impact of patient care arising from diagnostic errors has been estimated to arise in around 9% to 15% of errors, while the likelihood of inappropriate care has been described in 2% to 7% of such cases. Transient acute effects of consumption of alcohol i. There have been tremendous work and established quality control criteria for analytical phase of testing but there is paucity of standards for pre analytical phase.
Mar 09, 2017 attention to the preanalytical variables associated with blood collection is critical in ensuring accurate test results. Preanalytical and analytical factors affecting laboratory results. There are pre analytical, analytical and post analytical factors that contribute to accurate test results in clinical laboratories. Up to 70% of testing errors occur in the preanalytical phase1. Preanalytical variables evaluation in laboratory tests of. There are preanalytical, analytical and post analytical factors that contribute to accurate test results in clinical laboratories. Preanalytical variables of coagulation testing elite learning. Guder was director of the institute of clinical chemistry, bogenhausen community hospital munich and professor of clinical biochemistry at the ludwigmaximiliansuniversity of munich. These include the patients preanalytical condition, effects of. Preanalytical phase is most important in testing process and involves variables that are not under the control of the laboratory. Accidental as well as systematic errors in the preanalytical phase can lead to useless samples for metabolomics analysis.
The impact of preanalytical variables on the quality of laboratory results, 4th, updated edition walter g. Preanalytical variables and factors that interfere with the. Overall, a significant impact of patient care arising from diagnostic errors has been estimated to arise in around 9% to 15% of errors, while the likelihood of inappropriate care has been. Awareness of preanalytical variables affecting blood. Some of the preanalytical variables such as specimen variables can be controlled, while. Oct 27, 2018 on laboratory tests, the effect of alcohol may vary on the extent and duration of use. Study on preanalytical errors in a clinical biochemistry. The results of laboratory tests have a substantial role in the diagnostics of diseases.
Physicians should be educated on the potential for preanalytic variation and to question test results for potential preanalytic effects whenever the result does not match the clinical symptoms. This book is intended for everyone involved in patient care and using or performing laboratory tests. Preanalytical variables account for 3275% of laboratory errors, and encompass the time from when the test is ordered by the physician until the sample is ready for analysis. Quality assurance of the preanalytical phase acute care testing. The preanalytical phase encompasses all the processes from the time of a laboratory request made by the physician until the specimen is analyzed in the lab e. Preanalytical phase an overview sciencedirect topics. International standardization bodies such as the iso 6710 have issued standards for type and concentrations of anticoagulants to be used for venous blood samples 7. Preanalytic variables can affect test results, leading to misinterpretation and inappropriate patient care. Diagnostic technology for minimizing preanalytical errors. Effects of preanalytical variables on clinical laboratory tests ed. Pdf preanalytical variables and their influence on the. Young has made significant contributions to aacc and to laboratory medicine.
However, laboratory results do not always correspond with the patients clinical status. Preanalytical variables and their influence on the quality of laboratory results. The role of preanalytical factors in immunoassays introduction measurement of biochemical markers is an important aid to clinicians in the early detection, diagnosis, monitoring, and prognosis of disease. Laboratory testing can be divided into preanalytic, analytic, and postanalytic phases. Effects of preanalytical variables on clinical laboratory tests. Effects of preanalytical variables on clinical laboratory tests, american journal of clinical pathology, volume 101, issue 4, 1 april 1994, pages 549, we use cookies to enhance your experience on our website. So much care needs to be taken to deeply scrutinize this step of analysis and keep a tab on errors arising in it. By continuing to use our website, you are agreeing to our use of cookies. Therefore, current recommendations call for the laboratory. Better control of these variables will improve the total.
Preanalytical variation in clinical laboratory testing. The preanalytical phase of testing is equally important, but often falls outside the lab s direct control. Specimen quality plays a key role in assuring accuracy of those measurements in clinical laboratory testing. He is well known for his work as the principal editor and driving force behind the monumental effects series, a landmark collection of texts on the effects of drugs, disease, preanalytical variables, and herbals on laboratory tests. Therefore, each laboratory must be able to address these variables. Medical errors are most frequent in the preanalytic phase of testing. Clinical chemistry and the german society for laboratory. Pre analytical errors have a major impact on diagnostic accuracy of. The variation in specimen collection and effect of delay in sample pretreatment were examined in a specific study by collecting blood specimens from both arms of 10 persons from laboratory. The addition of new tests without stud ies proving their clinical utility. Smoking, high altitude, patient stance, exercise and pregnancy are some additional patientrelated variables over which the lab has no control. Jan 01, 2020 for other analytes, the effects may not be recognized by physicians as significant contributors to result in variation, such as posture and exercise. Physicians should be educated on the potential for preanalytic variation and to question test results for potential preanalytic effects whenever the result does not match the clinical. Nov 01, 1997 effects of preanalytical variables on clinical laboratory tests, 2nd edn.
Errors, preanalytical, analytical, post analytical, total testing process, quality. Preanalytical factors affecting the results of laboratory blood. Special aspects in clinical chemistry special tubes for hormones and proteomics. Preanalytic variables can affect test results, leading to. Improving quality at the preanalytical phase of blood sampling. It is not always clear when a sample is received in the lab that it may be unsuitable or compromised. Laboratory diagnostics, a pivotal part of clinical decision making, is no safer than other areas of healthcare, with most errors occurring in the manually intensive preanalytical process.
Breast cancer testing scandal shines spotlight on black box of clinical. Overconfidence in laboratory test results requests for multiple tests that are basically equivalent in their diseasedetection capacity quick and easy access to laboratory directory as a result of the use of new technologies. An international team of authors summarizes the information on biological influences, analytical interferences and on the variables affecting the collection, transport and storage, as well as preparation of samples. However, important sources of variation in the laboratory testing process are errors within the preanalytical phase before specimen analysis in the laboratory. Pre analytical errors have a major impact on diagnostic accuracy of laboratory results.
Young a book on effects of herbs and natural products on clinical laboratory tests. Preanalytical variables account for 3275% of laboratory errors, and encompass the time from when the test is ordered by the physician until the sample is ready. Preanalytical issues in the haemostasis laboratory the fritsma. Laboratory errors can often have serious adverse consequences. Effects of drugs on clinical laboratory tests d s young, 1997. The variation in specimen collection and effect of delay in sample pretreatment were examined in a specific study by collecting blood specimens from both arms of 10 persons from laboratory personnel at the labora. Apr 25, 2018 effect of preanalytical and analytical variables on the clinical utility of mean platelet volume. The impact of preanalytical variables on the quality of laboratory resul. Preanalytical errors and their impact on tests in clinical. Sample collection is often entitled as the simple part of a biomedical study. As with the other effects publications, the information is organized into five sections.
Preanalytical variables and factors that interfere with. Preanalytical variation in clinical laboratory testing setia major. The impact of preanalytical variables on the quality of laboratory results, 4th, updated edition wiley. Effect of preanalytical and analytical variables on the. Effects of preanalytical variables on clinical laboratory. An international team of authors summarizes the information on biological influences, analytical interferences and on the variables affecting the collection, transport.
Reducing preanalytical errors whitehat communications. General chemistry technical bulletin centrifugation the. It is to be hoped that the awareness of the importance of the preanalytical phase on the quality of medical laboratory results leads to a broader implementation of preanalytical aspects into national and international quality assurance programs, which may help to reduce its often underestimated portion of errors in laboratory results. Our recommendation is the use of the laboratory information management systems as a recording mechanism for preanalytical errors as this provides the easiest and most standardized mechanism of data capture. Effects of preanalytical variables on clinical laboratory tests, american journal of clinical pathology, volume 101, issue 4, 1 april 1994. Preanalytical variables and their influence on the quality of. Preanalytical factors may have either an animalrelated or a. Clinical decisions based on laboratory test values are correctly made only when the. Effects of herbs on laboratory results collection of specimen when to test. The preanalytical variables have great impact upon the quality. Kazmierczak, in accurate results in the clinical laboratory second edition, 2019 introduction. The impact of preanalytical variables on the quality of laboratory results guder, walter g. Preanalytic patient variables specimen variables collection handling processing analytic performance of selected laboratory test postanalytic test reporting variables recording reporting interpreting table 1. An example of the effect of age, sex and other variables on interpretation of laboratory results is serum alkaline.
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