Accuracy and clinical usefulness of the near-patient testing CoaguChek S international normalised ratio monitor in rural medical practice.
OBJECTIVE
To compare the accuracy and clinical usefulness of the near-patient testing CoaguChek S INR monitor in rural medical practice. DESIGN, SETTING AND MAIN OUTCOME MEASURES: General practices were identified through Australian university departments of rural health. Study investigators trained general practitioners and/or practice nurses in the use of the CoaguChek S INR monitor. General practices obtained a fingerprick sample for testing with the INR monitor to compare with conventional pathology testing for accuracy. An evaluation questionnaire was administered to users of the machine to assess ease of use and clinical usefulness.


RESULTS
A total of 169 patients from 15 general practice sites provided 401 paired (CoaguChek S and laboratory) INR results. The CoaguChek S was found to be accurate when compared to laboratory INR (r = 0.89), despite complicating variables such as multiple users of the monitor and multiple laboratories used for comparison with the CoaguChek S INR. Overall, 88% of dual INR measurements were within 0.5 INR units of each other. For laboratory INR </= 1.9, 2.0-3.5 and >/= 3.6, 97%, 90% and 57% of readings were within 0.5 INR units, respectively. Clinical agreement occurred 93% and 90% of the time against published expanded and narrow criteria, respectively.


CONCLUSIONS
The routine use of near-patient testing, with appropriate training and quality assurance programs, has the potential to increase the safety and efficacy of warfarin therapy in rural and remote communities.
Jackson
Shane L
SL
School of Pharmacy, University of Tasmania, Hobart, Tasmania.
Bereznicki
Luke R
LR
Peterson
Gregory M
GM
Marsden
Katherine A
KA
Jupe
David M L
DM
Vial
Janet H
JH
Rasiah
Rohan L
RL
Misan
Gary
G
Williams
Sharon M
SM
D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001315:Australia; D016903:Drug Monitoring / Q000295:instrumentation* / Q000592:standards; D005194:Family Practice / Q000706:statistics & numerical data; D006801:Humans; D019934:International Normalized Ratio / Q000295:instrumentation / Q000592:standards*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D019035:Rural Health Services / Q000592:standards* / Q000706:statistics & numerical data; D014859:Warfarin / Q000627:therapeutic use*
D000925:Anticoagulants; D014859:Warfarin