A multicentre randomised clinical endpoint study of parma 5 computer-assisted oral anticoagulant dosage

Leon Poller, Michelle Keown, Saied Ibrahim, Gordon Lowe, Marco Moia, Alexander G. Turpie, Christopher Roberts, Aton M H P Van Den Besselaar, Felix J M Van Der Meer, Armando Tripodi, Gualtiero Palareti, Jørgen Jespersen

Research output: Contribution to journalArticle


To meet growing demand for oral anticoagulation worldwide there has been increased dependence on computer-assistance in dosage although the safety and effectiveness of any of the individual computer-assisted dosage programs has not previously been established. This randomised multicentre clinical end-point study assessed a new version of the parma 5 program. It compared parma 5 safety and effectiveness with manual dosage by experienced medical staff at 19 centres with a known interest in oral anticoagulation. Target recruitment was 8000 patient-years, randomised to medical staff or parma-5 assisted dosage. Safety and effectiveness of the parma 5 program was compared with manual dosage. A total of 10 421 patients were recruited (15 369 patient-years) in the 5-year study. International normalised ratio (INR) tests numbered 167 791 with manual and 160 078 with parma 5 dosage. With parma 5 there was overall a non-significant reduction in clinical events but in the 2542 patients with deep vein thrombosis/pulmonary embolism, clinical events were significantly reduced (P = 0.005). Success in achieving 'time in target INR range' was also significantly greater with parma 5 compared with the dosage by experienced medical staff. This study demonstrated the safety and effectiveness of parma 5-assisted dosage.

Original languageEnglish
Pages (from-to)274-283
Number of pages10
JournalBritish Journal of Haematology
Issue number2
Publication statusPublished - Oct 2008



  • Clinical events
  • Computer dosage
  • International normalised ratio
  • Safety and effectiveness
  • Time-in-range

ASJC Scopus subject areas

  • Hematology

Cite this

Poller, L., Keown, M., Ibrahim, S., Lowe, G., Moia, M., Turpie, A. G., Roberts, C., Van Den Besselaar, A. M. H. P., Van Der Meer, F. J. M., Tripodi, A., Palareti, G., & Jespersen, J. (2008). A multicentre randomised clinical endpoint study of parma 5 computer-assisted oral anticoagulant dosage. British Journal of Haematology, 143(2), 274-283. https://doi.org/10.1111/j.1365-2141.2008.07337.x