Poller et al reported a method for the rapid determination of the International Sensitivity Index (ISI) for a coagulometer. The authors are from the University of Manchester, Hospital of South West Denmark, University of Southern Denmark and Hart Biologicals, Ltd.

Line estimates for the plot of a series of data reflecting:

(1) x axis: LN(certified INR)

(2) y axis: LN(local PT in seconds)



= 1 / (slope for the line)


mean normal prothrombin time = MNPT =

= EXP(intercept)



= ((measured PT) / (MNPT))^(ISI)

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