A computer implemented method of evaluating interaction two or more
medical products or conditions, in the context of a reference condition,
based on a dataset of patient records includes developing a reference
contingency lattice of lattice subsets from a subset of the patient
records containing the reference condition, wherein the lattice subsets
correspond to the number of patient records that contain each of the two
or more medical products or conditions and combinations thereof. A
plurality of comparison contingency lattices are developed, each of the
comparison contingency lattices developed from a respective random subset
of patient records not containing the reference condition, where each of
the comparison contingency lattices include lattice subsets that
correspond to the number of patient records that contain each of the two
or more medical products or conditions and combinations thereof. The
lattice subsets of the reference contingency lattice are compared to the
corresponding lattice subsets of the comparison contingency lattices to
determine whether a lattice subset is indicative of an interaction
between the medical products or conditions with respect to the reference
condition.