1. An apparatus for evaluating effects of treatments comprising: a processor; and a memory operably coupled to the processor and having program instructions stored therein, the processor being configured to execute the program instructions, the program instructions comprising: receiving record data of a plurality of subjects; identifying relevant characteristics for evaluation; identifying a first treatment; identifying a second treatment; identifying an effect; identifying, from among the subjects, a first group of subjects that received the first treatment; identifying, from among the subjects, a second group of subjects who did not receive the first treatment; assigning a weight to the record data of each subject of the second group of subjects corresponding to a likelihood that the corresponding subject would have received the first treatment to generate weighted record data of the second group of subjects; determining whether the weighted record data of the second group of subjects is balanced with the record data of the first group of subjects; adjusting the weight assigned to the record data of each subject of the second group of subjects to balance the weighted record data of the second group of subjects with the record data of the first group of subjects; determining an estimated relative likelihood, using the weighted record data of the second group of subjects to perform a regression, that the first treatment, as compared to the second treatment, will result in the effect; and outputting the estimated relative likelihood.