ABSTRACT
Point-of-care (POC) testing in the field of hemostasis is rapidly expanding in many
countries. This includes use of global tests of hemostasis in operating theaters and
especially use of POC monitors for determination of the international normalized ratio
(INR) for monitoring oral anticoagulant therapy. Issues related to internal quality
control and external quality assessment for these devices are reviewed. Data from
external quality assessment exercises involving users of several different POC-INR
devices is described, and use of split samples where a patient sample is analyzed
by both a POC device and by a conventional laboratory method is described.
KEYWORDS
Quality control - external quality assessment - hemostasis - POC - INR
REFERENCES
- 1 ISO/FDIS 17593 .Clinical Laboratory Testing and In Vitro Diagnostic Systems–In Vitro
Monitoring Systems for Oral Anticoagulant Therapy. Geneva, Switzerland; International
Standards Organization 2006
- 2
Tripodi A, Bressi C, Carpenedo M, Chantarangkul V, Clerici M, Mannucci P M.
Quality assurance program for whole blood prothrombin time-international normalized
ratio point-of-care monitors used for patient self-testing to control oral anticoagulation.
Thromb Res.
2004;
113
35-40
- 3
Kitchen S, Kitchen D P, Jennings I, Woods T AL, Walker I D, Preston F E.
Point of care INRs: UK NEQAS experiences demonstrates necessity for proficiency testing
of three different monitors.
Thromb Haemost.
2006;
96
590-596
- 4
Poller L, Keown M, Ibraham S A et al..
Quality assessment of Coaguchek Point-of-Care Prothrombin Time Monitors. Comparison
of the European Community-approved procedure and conventional external quality assessment.
Clin Chem.
2006;
52
1843-1847
- 5
Murray E T, Kitchen D P, Kitchen S et al.
Patient self-management of oral anticoagulation and external quality assessment.
Br J Haematol.
2003;
122
825-828
- 6
Murray E T, Jennings I, Kitchen D, Kitchen S, Fitzmaurice D A.
Quality assurance for oral anticoagulation self management: a cluster randomized trial.
J Thromb Haemost.
2008;
6
464-469
- 7
Kitchen D P, Murray E T, Jennings I et al..
Comparison of Coaguchek S INRS with hospital laboratory citrated plasma INRs. What
is the truth?.
Br J Haematol.
2005;
129(Suppl)
S1-S18
- 8 Expert WHO Committee on Biological Standardization .Guidelines for thromboplastins
and plasma used to control oral anticoagulation therapy. Geneva, Switzerland; World
Health Organ Tech Rep Serr 1999 889: 64-93
- 9
Watson C, Kitchen S, Woolley A M, Young L, Malia R G.
Recombinant and tissue extract thromboplastins for determination of INR.
Br J Biomed Sci.
1999;
56
123-127
- 10
Perry D J.
Factor VII deficiency.
Br J Haematol.
2002;
118
689-700
- 11
Solvik U O, Stavelin A, Christensen N G, Sandberg S.
External quality assessment of prothrombin time: the split-sample model compared with
external quality assessment with commercial control material.
Scand J Clin Lab Invest.
2006;
66
337-349
- 12
Kitchen D, Murray E T, Kitchen S et al..
External quality assessment for prothrombin time/international normalized ratio using
point-of-care devices: split-sample or conventional external quality assessment using
control samples?.
Scand J Clin Lab Invest.
2007;
67
673-675
- 13
Kitchen S, Walker I D, Woods T AL, Preston F E.
Thromboplastin related differences in the determination of international normalized
ratio: a cause for concern?.
Thromb Haemost.
1994;
72
426-429
- 14
Baglin T, Luddington R.
Reliability of delayed INR determination: implications for decentralized anticoagulant
care with off-site blood sampling.
Br J Haematol.
1997;
96
431-434
- 15
Leeming D R, Craig S, Stevenson K J, Tabener D.
The determination of INR in stored whole blood.
J Clin Pathol.
1998;
51
360-363
- 16
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
- 17
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
- 18
Lippi G, Montagnana M, Salvagno L, Guidi G S.
Interference of blood cell lysis in routine coagulation testing.
Arch Pathol Lab Med.
2006;
130
181-184
- 19
Marlar R A, Potts R M, Marlar A A.
Effect on routine and special coagulation testing values of citrate anticoagulant
adjustment in patients with high hematocrit values.
Am J Clin Pathol.
2006;
126
400-405
- 20
Fitzmaurice D A, Gardiner C, Kitchen S, Mackie I, Murray E T, Machin S.
An evidence based review and guidelines for patients self testing and management of
oral anticoagulation.
Br J Haematol.
2005;
131
156-165
- 21
Jennings I, Kitchen D P, Woods T AL, Kirtchen S, Walker I D.
Emerging technologies and Quality assurance: the UK NEQAS perspective.
Semin Thromb Hemost.
2007;
33
243-249
- 22
Cunningham M T, Brandt J T, Chandler W L et al..
Quality assurance in hemostasis: the perspective from the College of American Pathologists
Proficiency Testing Programme.
Semin Thromb Hemost.
2007;
33
250-258
Dianne P KitchenF.I.B.M.S.
Specialist Scientific Lead for Point of Care Programs, UK NEQAS for Blood Coagulation,
Rutledge Mews
3 Southbourne Road, Sheffield S10 2QN, UK
eMail: dianne.kitchen@coageqa.org.uk
