Quality Assurance in Hemostasis: The Perspective from the College of American Pathologists Proficiency Testing Program

ABSTRACT

External quality assurance (EQA) is an important component of the total quality assurance program of a clinical hemostasis laboratory. The College of American Pathologists (CAP) helps meet this requirement by providing a proficiency testing program that evaluates a broad range of hemostasis methods and analytes. This article reviews the published experience of the CAP proficiency testing program in hemostasis. The purpose is to formulate general conclusions about the benefits of EQA. Between 1963 and 2006, the performance characteristics of a variety of tests have been evaluated, including the prothrombin time, activated partial thromboplastin time, coagulation factor activity assays (e.g., fibrinogen, factor [F] VIII, FIX, FXI), von Willebrand factor assays, unfractionated heparin monitoring, lupus anticoagulant testing, and platelet function. Based on the results of these evaluations, the major benefits of EQA are to (1) enhance patient care and safety through improved laboratory testing; (2) characterize test accuracy and precision across multiple methods; (3) correlate specific method variables with accuracy and precision; (4) identify interfering substances and quantify their effects across multiple methods; (5) identify clinical laboratories that are at risk for poor performance so that their performance can improve; and (6) satisfy accreditation and regulatory requirements.

Coagulation - hemostasis testing - proficiency testing - quality assurance - quality control

REFERENCES

• 1 Miale J B, LaFond D J. 1963 prothrombin time test survey, College of American Pathologists, Standards Committee, Subcommittee on Coagulation.  Am J Clin Pathol. 1967;  47 40-59
• 2 Triplett D A. The College of American Pathologists (CAP) survey program.  Scand J Haematol. 1980;  37(suppl) 156-157
• 3 College of American Pathologists .Coagulation. Available at: http://www.cap.org/apps/docs/proficiency_testing/surveys_catalog/chapter_13.pdf Accessed March 6, 2007
• 4 Koepke J A. The 1969 survey of prothrombin time.  Am J Clin Pathol. 1970;  54 502-507
• 5 Koepke J A, Gilmer Jr P R, Triplett D A, O'Sullivan M B. The prediction of prothrombin time system performance using secondary standards.  Am J Clin Pathol. 1977;  68 191-194
• 6 Evatt B L, Brogan D, Triplett D, Koepke J, Waters G. Effect of thromboplastin and instrumentation on the prothrombin time test.  Clin Lab Haematol. 1981;  3 331-342
• 7 Koepke J A. The partial thromboplastin time in the CAP survey program.  Am J Clin Pathol. 1975;  63 990-994
• 8 Koepke J A, Gilmer Jr P R, Filip D J, Eckstein J D, Sibley C A. Studies of fibrinogen measurement in the CAP survey program.  Am J Clin Pathol. 1975;  63 984-989
• 9 Bovill E G, McDonagh J, Triplett D A et al.. Performance characteristics of fibrinogen assays. Results of the College of American Pathologists proficiency testing program 1988-1991.  Arch Pathol Lab Med. 1993;  117 58-66
• 10 Harms C S, Triplett D A, Koepke J A. Factor VIII (antihemophilic factor) assay results in the 1976 College of American Pathologists survey program.  Am J Clin Pathol. 1978;  70 560-562
• 11 Kocoshis T A, Triplett D A. CAP survey results for factor VIII assays (1977-1978).  Am J Clin Pathol. 1979;  72 346-361
• 12 Triplett D A, Kocoshis T A, Harms C S. Factor assay (VIII and IX) results in the College of American Pathologists survey program (1976-1979).  Scand J Haematol. 1980;  37(suppl) 116-129
• 13 Christensen R L, Triplett D A. Factor assay (VIII and IX) results in the College of American Pathologists survey program (1980-1982).  Am J Clin Pathol. 1983;  80(suppl) 633-642
• 14 Maas R L, Triplett D A, Tholen D. Factor VIII assay proficiency assessment: experience in the USA.  Scand J Haematol. Suppl 1984;  41 109-120
• 15 Brandt J T, Triplett D A, Musgrave K et al.. Factor VIII assays: assessment of variables.  Arch Pathol Lab Med. 1988;  112 7-12
• 16 Arkin C F, Bovill E G, Brandt J T, Rock W A, Triplett D A. Factors affecting the performance of factor VIII coagulant activity assays. Results of proficiency testing of the College of American Pathologists.  Arch Pathol Lab Med. 1992;  116 908-915
• 17 Brandt J T, Arkin C F, Bovill E G, Rock W A, Triplett D A. Evaluation of APTT reagent sensitivity to factor IX and factor IX assay performance. Results from the College of American pathologists survey program.  Arch Pathol Lab Med. 1990;  114 135-141
• 18 Pearson R W, Triplett D A. Factor XI assay results in the CAP survey (1981).  Am J Clin Pathol. 1982;  78(Suppl) 615-620
• 19 Hayes T E, Brandt J T, Chandler W L et al.. External peer review quality assurance testing in von Willebrand disease: the recent experience of the United States College of American Pathologists proficiency testing program.  Semin Thromb Hemost. 2006;  32 499-504
• 20 Triplett D A, Harms C S, Koepke J A. The effect of heparin on the activated partial thromboplastin time.  Am J Clin Pathol. 1978;  70 556-559
• 21 Brandt J T, Triplett D A. Laboratory monitoring of heparin: effect of reagents and instruments on the activated partial thromboplastin time.  Am J Clin Pathol. 1981;  76 530-537
• 22 Gawoski J M, Arkin C F, Bovill T, Brandt J, Rock W A, Triplett D A. The effects of heparin on the activated partial thromboplastin time of the College of American Pathologists survey specimens. Responsiveness, precision, and sample effects.  Arch Pathol Lab Med. 1987;  111 785-790
• 23 Brandt J T, Triplett D A, Rock W A, Bovill E G, Arkin C F. Effect of lupus anticoagulants on the activated partial thromboplastin time. Results of the College of American Pathologists survey program.  Arch Pathol Lab Med. 1991;  115 109-114
• 24 Cunningham M T, Praestgaard J, Styer P E et al.. A method for proficiency testing of small peer groups in the College of American Pathologists coagulation surveys.  Arch Pathol Lab Med. 1999;  123 199-205
• 25 Triplett DA Standardization of Coagulation Assays: An Overview. Skokie, IL; College of American Pathologists 1982
• 26 Triplett DA, Rock WA, Lucas FV, et al Advances in Coagulation Testing: Interpretation and Application. Skokie, IL; College of American Pathologists 1986
• 27 Brandt J T. College of American Pathologists Conference XXXI on laboratory monitoring of anticoagulant therapy. Introduction.  Arch Pathol Lab Med. 1998;  122 765-766
• 28 Olson J T. College of American Pathologists Consensus Conference XXXVI: Diagnostic issues in thrombophilia. Introduction and general considerations.  Arch Pathol Lab Med. 2002;  126 1277-1433
• 29 Smogorzewska A, Brandt J T, Chandler W L et al.. Effect of fondaparinux on coagulation assays: Results of College of American Pathologists proficiency testing.  Arch Pathol Lab Med. 2006;  130 1605-1611
• 30 Olson J, Cunningham M, Brandt J et al.. Use of the D-dimer for exclusion of VTE: difficulties revealed through the proficiency testing program of the College of American Pathologists (CAP).  J Thromb Haemost. 2006;  3(suppl 1) 419 (abst OR302)