PDF herunterladen
Thromb Haemost 1987; 58(03): 905-910
DOI: 10.1055/s-0038-1646013
Original Article
Schattauer GmbH Stuttgart

Oral Anticoagulant Therapy Control: Evidence that INR Expression Improves the Inter-Laboratory Comparability of Results - The Bologna Oral Anticoagulant Control Exercise

G Palareti
1   The Dept. of Angiology and Blood Coagulation, Hosp. S. Orsola (head Prof. S. Coccheri, supervisor of the exercise), Italy
,
S Coccheri
1   The Dept. of Angiology and Blood Coagulation, Hosp. S. Orsola (head Prof. S. Coccheri, supervisor of the exercise), Italy
,
M Poggi
1   The Dept. of Angiology and Blood Coagulation, Hosp. S. Orsola (head Prof. S. Coccheri, supervisor of the exercise), Italy
,
M Bonetti
2   Central Laboratory, Hosp. S. Orsola (head Prof. G. Bugiardini), Italy
,
V Cervi
3   Institute for Cardiovascular Dis., Hosp. S. Orsola (head Prof. B. Magnani), Italy
,
A Mazzuca
4   Central Laboratory, Hosp. Malpighi (head Prof. F. Barboni), Italy
,
M Savoia
5   Central Laboratory, Hosp. Maggiore (head Prof. M. Martuzzi), Italy
,
L Veri
6   Central Laboratory, Hosp. Bellaria (head Prof. L. Abate), Italy
,
F Fiori
7   Central Laboratory, Orthopedic Institutes Rizzoli (head Prof. A. Pizzoferrato), Italy
,
G Gaspari
8   Laboratories of Clinical Chemistry Mengoli and Tiarini of the USL, (Local Health Unit) N. 28 (responsible Dr. G. Gaspari), Italy
,
A Palareti
9   Statistician, Institute of Computer Science, University of Ancona, Italy
,
The Bologna oral anticoagulant control study group › Institutsangaben
Weitere Informationen

Publikationsverlauf

Received 05. Dezember 1986

Accepted after revision 11. Juni 1987

Publikationsdatum:
28. Juni 2018 (online)

Auch verfügbar auf
  als PDF herunterladen  Lizenzen und Reprints

Summary

The aims of the present study were: l) interlaboratory normalization of prothrombin time (PT) testing for anticoagulant therapy control through calibration of customary thromboplastins against international reference materials, and 2) “on field” validation of the advantages offered by expression of results as International Normalized Ratio (INR) as opposedto percentage activity. PT tests were carried out over 8 days on the same normal subjects (16) and patients on oral an ticoagulants (48) in the 9 laboratories of the Bologna area. The use of customary thromboplastins and coagulometers was maintained in all labs throughout the study. The main results were: 1) the interlaboratory CV of the prothrombin ratios obtained for each sample with all customary thromboplastins (5 different brands) was 15%, but was reduced to levels of 5.8 to 8.9 when using constant thromboplastin brands and batches; 2) the International Sensitivity Index (ISI) values obtained in the different labs were only slightly influenced by the use of different coagulometers; 3) comparable ISI values were obtained through direct calibration with the international reference material and through intermediate calibration with a locally selected standard; 4) use of INR values instead of percentage activity greatly reduced interlaboratory variability and significantly improved uniformity of anticoagulation level measurements. thus reducing the possibility of erroneous prescriptions. The Bologna exercise is therefore of educational value for laboratory and community doctors of the area in understanding and accepting the INR system.

Keywords

Anticoagulant control - INR-PT normalization - PT expression
 

  • References

  • 1 Lam-Po-Tang P RL C, Poller L. Oral anticoagulant therapy and its control: an international survey. Thrombos Diath Haemorrh 1975; 34: 419-425
    PubMedSuche in Google Scholar
  • 2 WHO Expert Committee on Biological Standardization. 33rd Report. Tech Rep Ser 687. p. 81 WHO; Geneva: 1983
    Suche in Google Scholar
  • 3 Loeliger EA. ICSH/ICTH recommendations for reporting prothrombin time in oral anticoagulant control. Thromb Haemostas 1985; 53: 155-156
    PubMedSuche in Google Scholar
  • 4 Community Bureau of Reference. Certified Reference Material; BCR No 149. Brussels 1981.
    PubMed
  • 5 Community Bureau of Reference. BCR information. The certification of three Reference Materials for Thromboplastins. EUR 7763, Brussels 1984.
    PubMed
  • 6 Lehmann EL. Non parametrics: statistical methods based on ranks. McGraw-Hill; New York: 1975. chapter 6 p. 260
  • 7 Van der Velde EA. Orthogonal regression equation. In: Thromboplastin Calibration and Oral Anticoagulant Control. Van den Besselaar A MH P, Gralnick HR, Lewis SM. (Eds). Martinus Nijhoff Publ; The Hague: 1984. p. 25
    Suche in Google Scholar
  • 8 Quick AJ, Stanley-Brown M, Bancroft FW. A study of the coagulation defect in hemophilia and in jaundice. Am J Med Sci 1935; 190: 501-511
    CrossrefPubMedSuche in Google Scholar
  • 9 Conley CL, Morse WI. Thromboplastin factors in the estimation of prothrombin concentration. Am J Med Sci 1948; 215: 158-164
    CrossrefPubMedSuche in Google Scholar
  • 10 Verstraete M, Clark PA, Wrigth IS. Use of different tissue thromboplastins in the control of anticoagulant therapy. Circulation 1957; 16: 213-226
    CrossrefPubMedSuche in Google Scholar
  • 11 Zucker S, Brosious E, Cooper GR. One-stage prothrombin time survey. Am J Clin Pathol 1970; 53: 340-347
    CrossrefPubMedSuche in Google Scholar
  • 12 ICTII/ICSII. PioLhioinbm Lime siandardization: Repoitol Llie Expert Panel on Anticoagulant Control. Thromb Haemostas 1979; 42: 1073-1114
    PubMedSuche in Google Scholar
  • 13 Koepke J. Evaluation of materials and methods for coagulation testing. In: Quality control and laboratory medicine. Henry JB, Giegel JL. (Eds). Masson; New York: 1977. p. 157-166
    Suche in Google Scholar
  • 14 Biggs R, Denson K WE. Standardization of the one-stage prothrombin time for the control of anticoagulant therapy. Br Med J 1967; 1: 84-88
    CrossrefPubMedSuche in Google Scholar
  • 15 Poller L. A national standard for anticoagulant therapy. The Manchester comparative reagent. Lancet 1967; 1: 491-493
    PubMedSuche in Google Scholar
  • 16 Duckert F, Marbet GA. Die Kontrolle der oralen Antikoagulation. Der therapeutische Bereich. Schweiz Med Wochenschr 1977; 107: 1308
    PubMedSuche in Google Scholar
  • 17 Evatt BL, 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
    PubMedSuche in Google Scholar
  • 18 Starr H, Rhoades P, Lam-Po-Tang P RL C, Archer GT. Prothrombin times: an evaluation of four thromboplastins and four machines. Pathology 1980; 12: 567-573
    CrossrefPubMedSuche in Google Scholar
  • 19 Van den Besselaar A MH P. Proficiency testing and standardization of prothrombin time: effect of thromboplastin, instrumentation and plasma. Am J Clin Pathol 1984; 82: 688-699
    CrossrefPubMedSuche in Google Scholar
  • 20 Van den Besselaar A MH P. Standardization of the prothrombin time in oral anticoagulant control. Haemostasis 1985; 15: 271-277
    PubMedSuche in Google Scholar
  • 21 Hermans J. The European Community Bureau of Reference Calibration Study. In: Thromboplastin Calibration and Oral Anticoagulant Control. Van den Besselaar A MH P, Gralnick HR, Lewis SM. (Eds). Martinus Nijhoff Publ; The Hague: 1984. p. 41
    Suche in Google Scholar
  • 22 Loeliger EA, Van den Besselaar A MH P, Lewis SM. Reliability and clinical impact of the normalization of the prothrombin limes in oral aulicoagulanl control. Thromb Ilaemostais 1985; 53: 148-154
    PubMedSuche in Google Scholar