Preanalytical and Postanalytical Variables: The Leading Causes of Diagnostic Error in Hemostasis?

ABSTRACT

The advent of modern instrumentation, with associated improvements in test reliability, together with appropriate internal quality control and external quality assurance measures, has led to substantial reduction in analytical errors within hemostasis laboratories. Unfortunately, the reporting of incorrect or inappropriate test results still occurs, perhaps even as frequently as in the past. Many of these cases will arise due to a variety of events largely outside the control of the laboratories performing the laboratory tests and primarily comprise preanalytical events related to patient collection and sample processing and postanalytical events related to the reporting and interpretation of test results. The current article provides an overview of these events and provides some suggestions on how they can be minimized or prevented to ensure that the test results the clinician receives actually represent the true clinical status of the patient under investigation rather than just reflecting the status of an (inappropriate) clinical sample received and tested. This article should be of interest to both laboratory scientists working in hemostasis and the clinicians that request such tests. The former, because these are ultimately responsible for the test results they provide to clinicians, and there is a duty of care to provide both accurate and precise results to enable clinicians to manage patients appropriately and to avoid the need to recollect and retest. The latter because unless clinicians gain an appreciation of these issues, they will not be in a position to best manage their patients.

KEYWORDS

Preanalytical variables - postanalytical variables - extra-analytical variables - diagnostic errors - hemostasis

REFERENCES

• 1 Lippi G, Guidi G C. Risk management in the preanalytical phase of laboratory testing.  Clin Chem Lab Med. 2007;  45 720-727
• 2 Lippi G, Guidi G C, Mattiuzzi C, Plebani M. Pre-analytical variability: the dark side of the moon in laboratory testing.  Clin Chem Lab Med. 2006;  44 358-365
• 3 Lippi G, Banfi G, Buttarello M for the Italian Intersociety SIBioCSIMeL-CISMEL Study Group on Extraanalytical Variability et al.. Recommendations for detection and management of unsuitable samples in clinical laboratories.  Clin Chem Lab Med. 2007;  45 728-736
• 4 Lippi G, Fostini R, Guidi G C. Quality improvement in laboratory medicine: extra-analytical issues.  Clin Lab Med. 2008;  28 285-294
• 5 Adcock D M, Hoefner D M, Kottke-Marchant K, Marlar R A, Szamosi D I, Warunek D J. Collection, Transport, and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays and Molecular Hemostasis Assays: Approved Guideline-Fifth Edition. CLSI document H21–A5. Wayne, PA; Clinical Laboratory Standards Institute 2008
• 6 Plebani M. The clinical importance of laboratory reasoning.  Clin Chim Acta. 1999;  280 35-45
• 7 Lippi G, Franchini M, Montagnana M, Salvagno G L, Poli G, Guidi G C. Quality and reliability of routine coagulation testing: can we trust that sample?.  Blood Coagul Fibrinolysis. 2006;  17 513-519
• 8 Kiechle F L, Adcock D M, Calam R R, Davis C, Schwartz J G. So You're Going to Collect a Blood Specimen. An Introduction to Phlebotomy. 12th ed. Northfield, IL; College of American Pathologists 2007
• 9 Joint Commission on Accreditation of Healthcare Organizations .2008 National Patient Safety Goals. Available at: http://www.jointcommission.org/PatientSafety/NationalPatientSafetyGoals/08_amb_npsgs.htm Accessed August 16, 2008
• 10 Payne S, MacKinnon K, Keeney M, Morrow B, Kovacs M J. Effect of 3.2 vs. 3.8% sodium citrate concentration on anti-Xa levels for patients on therapeutic low molecular weight heparin.  Clin Lab Haematol. 2003;  25 317-319
• 11 Danielson C F, Davis K, Jones G, Benson J, Arney K, Martin J. Effect of citrate concentration in specimen collection tubes on the international normalized ratio.  Arch Pathol Lab Med. 1997;  121 956-959
• 12 Adcock D M, Kressin D C, Marlar R A. Effect of 3.2% vs 3.8% sodium citrate concentration on routine coagulation testing.  Am J Clin Pathol. 1997;  107 105-110
• 13 Lippi G, Salvagno G L, Montagnana M, Guidi G C. Influence of two different buffered sodium citrate concentrations on coagulation testing.  Blood Coagul Fibrinolysis. 2005;  16 381-383
• 14 Jilma B. Platelet function analyzer (PFA-100): a tool to quantify congenital or acquired platelet dysfunction.  J Lab Clin Med. 2001;  138 152-163
• 15 Crescente M, Di Castelnuovo A, Iacoviello L, Vermylen J, Cerletti C, de Gaetano G. Response variability to aspirin as assessed by the platelet function analyzer (PFA)-100. A systematic review.  Thromb Haemost. 2008;  99 14-26
• 16 Ernst D J, Balance L O, Calam R R et al.. Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture. Approved Standard-Sixth Edition. CLSI document H3–A6. Wayne, PA; Clinical and Laboratory Standards Institute 2007
• 17 Adcock D M, Kressin D C, Marlar R A. Are discard tubes necessary in coagulation studies?.  Lab Med. 1997;  28 530-533
• 18 Lippi G, Guidi G C. Effect of specimen collection on routine coagulation assays and D-dimer measurement.  Clin Chem. 2004;  50 2150-2152
• 19 Adcock D M, Kressin D C, Marlar R A. Minimum specimen volume requirements for routine coagulation testing. Dependence on citrate concentration.  Am J Clin Pathol. 1998;  109 595-599
• 20 Chuang J, Sadler M A, Witt D M. Impact of evacuated collection tube fill volume and mixing on routine coagulation testing using 2.5 mL (pediatric) tubes.  Chest. 2004;  126 1262-1266
• 21 Adcock D M. Sample integrity and preanalytical variables. In: Preston E, Olsen J, Kitchen S Quality in Laboratory Hemostasis and Thrombosis. West Sussex, United Kingdom; Wiley Blackwell 2009: 31-42
• 22 Lippi G, Salvagno G L, Montagnana M, Guidi G C. Influence of primary sample mixing on routine coagulation testing.  Blood Coagul Fibrinolysis. 2007;  18 709-711
• 23 Laxson C J, Titler M G. Drawing coagulation studies from arterial lines. An integrative literature review.  Am J Crit Care. 1994;  3 16-22
• 24 Powers J M. Obtaining blood samples for coagulation studies from a normal saline lock.  Am J Crit Care. 1999;  8 250-253
• 25 Lippi G, Salvagno G L, Montagnana M, Poli G, Guidi G C. Influence of the needle bore size on platelet count and routine coagulation testing.  Blood Coagul Fibrinolysis. 2006;  17 557-561
• 26 Lippi G, Salvagno G L, Guidi G C. No influence of butterfly device on routine coagulation assays and D-dimer measurement.  J Thromb Haemost. 2005;  3 389-391
• 27 Lippi G, Salvagno G L, Montagnana M, Guidi G C. Short-term venous stasis influences routine coagulation testing.  Blood Coagul Fibrinolysis. 2005;  16 453-458
• 28 Zürcher M, Sulzer I, Barizzi G, Lämmle B, Alberio L. Stability of coagulation assays performed in plasma from citrated whole blood transported at ambient temperature.  Thromb Haemost. 2008;  99 416-426
• 29 Adcock D, Kressin D, Marlar R A. The effect of time and temperature variables on routine coagulation tests.  Blood Coagul Fibrinolysis. 1998;  9 463-470
• 30 Lippi G, Salvagno G L, Montagnana M, Poli G, Guidi G C. Influence of centrifuge temperature on routine coagulation testing.  Clin Chem. 2006;  52 537-538
• 31 Lippi G, Salvagno G L, Montagnana M, Manzato F, Guidi G C. Influence of the centrifuge time of primary plasma tubes on routine coagulation testing.  Blood Coagul Fibrinolysis. 2007;  18 525-528
• 32 Aursnes I, Vikholm V. On possible interaction between ADP and mechanical stimulation of platelet activation.  Thromb Haemost. 1984;  51 54-56
• 33 Favaloro E J, Mohammed A, Coombs R, Mehrabani P A. Filtered plasma as a potential cause of clinical misdiagnosis: inappropriate testing in a haematology laboratory.  Br J Biomed Sci. 1995;  52 243-248
• 34 Favaloro E J, Facey D, Grispo L. Laboratory assessment of von Willebrand factor: use of different assays can influence the diagnosis of von Willebrand's disease, depending on differing sensitivity to sample preparation and differential recognition of high molecular weight VWF forms.  Am J Clin Pathol. 1995;  104 264-271
• 35 Favaloro E J. Pre-analytical variables in coagulation testing.  Blood Coagul Fibrinolysis. 2007;  18 86-89
• 36 van Geest-Daalderop J H, Mulder A B, Boonman-de Winter L J, Hoekstra M M, van den Besselaar A M. Preanalytical variables and off-site blood collection: influences on the results of the prothrombin time/international normalized ratio test and implications for monitoring of oral anticoagulant therapy.  Clin Chem. 2005;  51 561-568
• 37 Salvagno G L, Lippi G, Montagnana M, Franchini M, Poli G, Guidi G C. Influence of temperature and time before centrifugation of specimens for routine coagulation testing.  Int J Lab Hematol. 2008;  (Mar) , 25 [Epub ahead of print]
• 38 Favaloro E J, Mehrabani P A. Laboratory assessment of von Willebrand factor: differential influence of prolonged ambient temperature specimen storage on assay results.  Haemophilia. 1996;  2 218-223
• 39 Favaloro E J, Nair S C, Forsyth C J. Collection and transport of samples for laboratory testing in von Willebrand's disease (VWD): time for a reappraisal?.  Thromb Haemost. 2001;  86 1589-1590
• 40 Favaloro E J, Soltani S, McDonald J. Potential laboratory misdiagnosis of haemophilia and von Willebrand disorder due to cold activation of blood samples for testing.  Am J Clin Pathol. 2004;  122 686-692
• 41 Böhm M, Täschner S, Kretzschmar E, Gerlach R, Favaloro E J, Scharrer I. Cold storage of citrated whole blood induces drastic time-dependent losses in factor VIII and von Willebrand factor: Potential for misdiagnosis of haemophilia and von Willebrand's disease.  Blood Coagul Fibrinolysis. 2006;  17 39-45
• 42 Woodhams B, Giradot O, Blanco M J, Colesse G, Gourmelin Y. Stability of coagulation proteins in frozen plasma.  Blood Coagul Fibrinolysis. 2001;  12 229-236
• 43 Lippi G, Salvagno G L, Rossi L, Montagnana M, Franchini M, Guidi G C. Analytical performances of the D-dimer assay for the Immulite 2000 automated immunoassay analyser.  Int J Lab Hematol. 2007;  29 415-420
• 44 Babson A L, Opper C A, Crane L J. Kinetic latex agglutinometry I. A rapid, quantitative immunologic assay for fibrinogen.  Am J Clin Pathol. 1982;  77 424-429
• 45 Favaloro E J, Bonar R, Duncan E et al.. on behalf of the RCPA QAP in Haematology Haemostasis Committee). Identification of factor inhibitors by diagnostic haemostasis laboratories: a large multi-centre evaluation.  Thromb Haemost. 2006;  96 73-78
• 46 Favaloro E J, Bonar R, Duncan E et al.. on behalf of the RCPA QAP in Haematology Haemostasis Committee). Mis-identification of factor inhibitors by diagnostic haemostasis laboratories: recognition of pitfalls and elucidation of strategies. A follow up to a large multicentre evaluation.  Pathology. 2007;  39 504-511
• 47 Kottke-Marchant K, Duncan A. Antithrombin deficiency: issues in laboratory diagnosis.  Arch Pathol Lab Med. 2002;  126 1326-1336
• 48 Lippi G, Blanckaert N, Bonini P et al.. Haemolysis: an overview of the leading cause of unsuitable specimens in clinical laboratories.  Clin Chem Lab Med. 2008;  46 764-772
• 49 Lippi G, Montagnana M, Salvagno G L, Guidi G C. Interference of blood cell lysis on routine coagulation testing.  Arch Pathol Lab Med. 2006;  130 181-184
• 50 van der Merwe L, Reyers F. The effect of hemolysis on plasma antithrombin activity as determined by a chromogenic method.  Vet Clin Pathol. 2007;  36 55-59
• 51 Marlar R A, Potts R M, Marlar A A. Effect of routine and special coagulation testing values of citrate anticoagulant adjustment in patients with high hematocrit values.  Am J Clin Pathol. 2006;  126 400-405
• 52 O'Brien J R. Relation to blood-coagulation to lipaemia.  Lancet. 1955;  269 690-693
• 53 Larsen L F, Bladbjerg E M, Jespersen J, Marckmann P. Effects of dietary fat quality and quantity on postprandial activation of blood coagulation factor VII.  Arterioscler Thromb Vasc Biol. 1997;  17 2904-2909
• 54 Freese R, Mutanen M. Postprandial changes in platelet function and coagulation factors after high-fat meals with different fatty acid compositions.  Eur J Clin Nutr. 1995;  49 658-664
• 55 Junker R, Pieke B, Schulte H et al.. Changes in hemostasis during treatment of hypertriglyceridemia with a diet rich in monounsaturated and n-3 polyunsaturated fatty acids in comparison with a low-fat diet.  Thromb Res. 2001;  101 355-366
• 56 Moreno P, Ginel P J. Effects of haemolysis, lipaemia and bilirubinaemia on prothrombin time, activated partial thromboplastin time and thrombin time in plasma samples from healthy dogs.  Res Vet Sci. 1999;  67 273-276
• 57 Law R C, Willatts S M. Lipaemia affecting automated clotting results.  Anaesthesia. 1993;  48 1011
• 58 Junker R, Käse M, Schulte H, Bäumer R, Langer C, Nowak-Göttl U. Interferences in coagulation tests—evaluation of the 570-nm method on the Dade Behring BCS analyzer.  Clin Chem Lab Med. 2005;  43 244-252
• 59 Favaloro E J, Soltani S, McDonald J, Grezchnik E, Easton L. Laboratory identification of familial thrombophilia: do the pitfalls exceed the benefits? A reassessment of ABO-blood group, gender, age and other laboratory parameters on the potential influence on a diagnosis of protein C, protein S and antithrombin deficiency and the potential high risk of a false positive diagnosis.  Lab Hematol. 2005;  11 174-184
• 60 Favaloro E J. Diagnostic issues in thrombophilia: a laboratory scientist's view.  Semin Thromb Hemost. 2005;  31 11-16
• 61 Favaloro E J. More on ‘universal’ versus ‘selected’ screening for thrombophilia: the hidden costs of false-positive diagnosis.  Br J Haematol. 2006;  134 239-240
• 62 Lippi G, Salvagno G L, Rugolotto S et al.. Routine coagulation tests in newborn and young infants.  J Thromb Thrombolysis. 2007;  24 153-155
• 63 Favaloro E J, Soltani S, McDonald J, Grezchnik E, Easton L, Favaloro J WC. Reassessment of ABO-blood group, gender and age on laboratory parameters used to diagnose von Willebrand disorder (VWD): potential influence on the diagnosis versus the potential association with risk of thrombosis.  Am J Clin Pathol. 2005;  124 910-917
• 64 Monagle P, Barnes C, Ignjatovic V et al.. Developmental haemostasis. Impact for clinical haemostasis laboratories.  Thromb Haemost. 2006;  95 362-372
• 65 Favaloro E J. Laboratory identification of von Willebrand disease: technical and scientific perspectives.  Semin Thromb Hemost. 2006;  32 456-471
• 66 Lippi G, Franchini M, Brocco G, Manzato F. Influence of the ABO blood type on the platelet function analyzer PFA-100.  Thromb Haemost. 2001;  85 369-370
• 67 Favaloro E J, Mehrabani P A, Koutts J. Laboratory assessment of von Willebrand factor: altered interpretation of laboratory data, and altered diagnosis of von Willebrand's disease, as influenced by the use of different vWF assays and assay conditions.  Clin Appl Thromb Hemost. 1997;  3 110-118
• 68 Adcock D M, Brien W F, Duff S L et al.. Procedures for Validation of INR and Local Calibration of PT/INR Systems; Approved Guideline. H54-A, Vol. 25 No. 23 (replaces H54-P, Vol. 24 No. 30). Wayne, PA; Clinical and Laboratory Standards Institute 2005
• 69 Favaloro E J, Hamdam S, McDonald J, McVicker W, Ule V. Time to think outside the box? Prothrombin time (PT), international normalized ratio (INR), international sensitivity index (ISI), mean normal prothrombin time (MNPT) and measurement of uncertainty (MU): a novel approach to standardisation.  Pathology. 2008;  40 277-287
• 70 Favaloro E J, Adcock D M. Standardization of the INR: how good is your laboratory's INR and can it be improved?.  Semin Thromb Hemost. 2008;  34 593-603
• 71 Brandt J T, Triplett D A, Alving B, Scharrer I. Criteria for the diagnosis of lupus anticoagulants: an update. On behalf of the Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibody of the Scientific and Standardisation Committee of the ISTH.  Thromb Haemost. 1995;  74 1185-1190
• 72 Greaves M, Cohen H, Machin S J, Mackie I. Guidelines on the investigation and management of the antiphospholipid syndrome.  Br J Haematol. 2000;  109 704-715
• 73 Ledford-Kraemer M R. Laboratory testing for lupus anticoagulants: pre-examination variables, mixing studies and diagnostic criteria.  Semin Thromb Hemost. 2008;  34 380-388
• 74 Tripodi A. Laboratory testing for lupus anticoagulants: diagnostic criteria and use of screening, mixing and confirmatory studies.  Semin Thromb Hemost. 2008;  34 373-379
• 75 Carroll W E, Wollitzer A O, Harris L, Ling M C, Whitaker W L, Jackson R D. The significance of platelet counts in coagulation studies.  J Med. 2001;  32 83-96
• 76 Watson H G, Greaves M. Can we predict bleeding?.  Semin Thromb Hemost. 2008;  34 97-103
• 77 Chee Y L, Crawford J C, Watson H G, Greaves M. Guidelines on the assessment of bleeding risk prior to surgery or invasive procedures. British Committee for Standards in Haematology.  Br J Haematol. 2008;  140 496-504
• 78 Lippi G, Franchini M, Brazzarola P, Manzato F. Preoperative screening: the rationale of measuring APTT in risk assessment.  Haematologica. 2001;  86 328
• 79 Lippi G, Salvagno G L, Montagana M, Guidi G C. Chronic influence of vigorous aerobic training on hemostasis.  Blood Coagul Fibrinolysis. 2005;  16 533-534
• 80 Banfi G, Del Fabbro M. Biological variation in tests of haemostasis.  Semin Thromb Hemost. 2008;  34
• 81 Spencer F A, Becker R C. Circadian variations in acute myocardial infarction.  J Am Coll Cardiol. 2003;  41 2143-2146
• 82 Dalby M C, Davidson S J, Burman J F, Davies S W. Diurnal variation in platelet aggregation iwth the PFA-100 platelet function analyser.  Platelets. 2000;  11 320-324
• 83 Bethel M, Adcock D, Zalevsky J, Young M, Fagrell B. Polyethylene glycol-induced prolongation of aPTT in two biopharmaceuticals.  Int J Lab Hematol. 2007;  29(Suppl 1) 69 , (Abst)
• 84 Webster P S, Oleson Jr F B, Paterson D L et al.. Interaction of daptomycin with two recombinant thromboplastin reagents leads to falsely prolonged patient prothrombin time/international normalized ratio results.  Blood Coagul Fibrinolysis. 2008;  19 32-38
• 85 Georgiou A, Westbrook J I. Computerized order entry systems and pathology services—a synthesis of the evidence.  Clin Biochem Rev. 2006;  27 79-87
• 86 Favaloro E J, Bonar R, Sioufi J et al.. (on behalf of the RCPA QAP in Haematology). Multi-laboratory testing of thrombophilia: current and past practice in Australasia as assessed through the Royal College of Pathologists of Australasia Quality Assurance Program in Haematology.  Semin Thromb Hemost. 2005;  31 49-58
• 87 Favaloro E J, Orsag I, Bukuya M, McDonald D. A nine-year retrospective assessment of laboratory testing for activated protein C resistance: evolution of a novel approach to thrombophilia investigations.  Pathology. 2002;  34 348-355
• 88 Favaloro E J, Mirochnik O, McDonald D. Functional activated protein C resistance assays: correlation with factor V DNA analysis is better with RVVT- than APTT-based assays.  Br J Biomed Sci. 1999;  56 23-33
• 89 Favaloro E J, Bonar R, Kershaw G et al.. (on behalf of the RCPA QAP in Haematology). Laboratory diagnosis of von Willebrand disorder: Use of multiple functional assays reduces diagnostic error rates.  Lab Hematol. 2005;  11 91-97
• 90 Favaloro E J, Bonar R, Kershaw G et al.. (on behalf of the RCPA QAP in Haematology). Reducing errors in identification of von Willebrand disease: the experience of the Royal College of Pathologists of Australasia Quality Assurance Program.  Semin Thromb Hemost. 2006;  32 505-513
• 91 Favaloro E J, Bonar R, Meiring M, Street A, Marsden K. (on behalf of the RCPA QAP in Haematology). 2B or not 2B? Disparate discrimination of functional VWF discordance using different assay panels or methodologies may lead to success or failure in the early identification of type 2B VWD.  Thromb Haemost. 2007;  98 346-358
• 92 Favaloro E J. An update on the von Willebrand factor collagen binding (VWF:CB) assay: 21 years of age and beyond adolescence, but not yet a mature adult.  Semin Thromb Hemost. 2007;  33 727-744
• 93 Favaloro E J. Detailed von Willebrand factor multimer analysis in patients with von Willebrand disease in the European study, molecular and clinical markers for the diagnosis and management of type 1 von Willebrand disease (MCMDM-1VWD) – a rebuttal.  J Thromb Haemost. 2008;  6 1999-2001
• 94 Favaloro E J, Wong R CW. Laboratory testing and identification of antiphospholipid antibodies and the antiphospholipid syndrome: a potpourri of problems, a compilation of possible solutions.  Semin Thromb Hemost. 2008;  34 389-410
• 95 Reber G, Boehlen F, de Moerloose P. Technical aspects in laboratory testing for antiphospholipid antibodies: is standardization an impossible dream?.  Semin Thromb Hemost. 2008;  34 340-346
• 96 Berntorp E, Salvagno G L. Standardization and clinical utility of thrombin generation assays.  Semin Thromb Hemost. 2008;  34 670-682
• 97 Enjeti A K, Lincz L F, Seldon M. Detection and measurement of microparticles: an evolving research tool for vascular biology.  Semin Thromb Hemost. 2007;  33 771-779
• 98 Enjeti A K, Lincz L, Seldon M. Microparticles in health and disease.  Semin Thromb Hemost. 2008;  34 683-692
• 99 Wong R C, Gillis D, Adelstein S et al.. Consensus guidelines on anti-cardiolipin antibody testing and reporting.  Pathology. 2004;  36 63-68
• 100 Wong R C, Favaloro E J, Adelstein S et al.. Consensus guidelines on anti-beta2 glycoprotein I testing and reporting.  Pathology. 2008;  40 58-63
• 101 Plebani M. What information on quality specifications should be communicated to clinicians, and how?.  Clin Chim Acta. 2004;  346 25-35