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.