Patients Prefer Self Testing.

Researchers in the UK conducted a prospective study to determine whether patients can achieve accurate INR values through patient self testing, using the CoaguChek S (Roche Diagnostics, Lewes, UK).

The main outcome measurements were:

  • comparability of INR values obtained by patient self testing and the hospital laboratory,
  • patient acceptability as assessed by a questionnaire, and
  • anticoagulant control.


  • Comparison of INRs showed no significant differences between the CoaguChek (median INR 3.02) and laboratory testing (median INR 3.07).
  • There was excellent correlation between the two methods (r =0.95), with 85% of CoaguChek results within 0.5 INR units of the laboratory method.
  • On four occasions, differences of >1 unit INR were obtained, but in each case the patient's anticoagulation was unstable (INR >4.5 by both methods) and the differences in INR would not have altered patient management.
  • 87% of patients found self-testing straightforward; 87% were confident in the result they obtained; and 77% preferred self-testing.


Patient self testing is a reliable alternative to clinic testing. The majority of patients prefer self testing over lab testing and self reported a high degree of confidence in their own ability to conduct the simple fingerstick test.

Source: Chris Gardiner, et al British Journal of Haematology, 128, 242–247