3.1.3 Association Rule Discovery
Association rules represent a promising technique to improve
heart disease prediction. Unfortunately, when association rules are
applied on a medical data set, they produce an extremely large
number of rules. Most of such rules are medically irrelevant and
the time required to find them can be impractical. In [11], four
constraints were proposed to reduce the number of rules: item
filtering, attribute grouping, maximum itemset size, and
antecedent/consequent rule filtering. When association rules are
applied on a medical data set, they produce an extremely large
number of rules. Most of such rules are medically irrelevant and
the time required to find them can be impractical. A more
important issue is that, in general, association rules are mined on
the entire data set without validation on an independent sample.
To solve these limitations, the author has introduced an algorithm
that uses search constraints to reduce the number of rules, searches
for association rules on a training set, and finally validates them
on an independent test set. Instead of using only Support and
confidence, one more parameter i.e. lift have been used as the
metrics to evaluate the medical significance and reliability of
association rules. Medical doctors use sensitivity and specificity as
two basic statistics to validate results. Sensitivity is defined as the
probability of correctly identifying sick patients, whereas