A fuzzy causal measure of individual patient treatment response

Abstract

We (2002) previously defined a necessary and sufficient causal ground to derive a formal causal ground in the unit hypercube. In addition we derived the clinical causal effect. These measures are developed from the fuzzy subset theorem as defined by Kosko (1992) and are in units of cardinality. In this paper we develop a measure of clinical efficiency K which is expressed in units of cardinality and is derived from the measures of formal causal ground and clinical causal effect. The measure of clinical efficiency was applied to 16 patients on an antiplatelet therapy. It renders a unique measure of clinical therapeutic effect for each patient. The measure of clinical efficiency developed herein can be used as an alternative to probability-based statistics to judge clinical causality.