A Cost-Effective Agent for Clinical Trial Assignment Princeton K. Kokku Lawrence O. Hall Dmitry B. Goldgof Eugene Fink Jeffrey P. Krischer

Clinical Trials A clinical trial is an evaluation of a new treatment procedure Researchers recruit patients with appropriate health problems and medical histories

Gotay [1991] showed that only 39% of the eligible patients are selected for clinical trials Fallowfield et al. [1997] showed that less than 50% of the eligible patients are selected Selection of Subjects The selection of subjects for clinical trials is a manual procedure, and researchers may miss some of the eligible patients.

Medical Tests The total cost of related medical tests may depend on their ordering Finding the right ordering is usually a complex optimization problem

Expert System Automatic selection of subjects for clinical trials Cost-effective ordering of related tests Explanation of the reasons for acceptance or rejection

System Design Interface Knowledge base Inference rules Ordering of tests

Interface Entry of patients’ data Emulation of a doctor-patient interview Explanation of the eligibility decisions

Knowledge Base Tests and questions Eligibility criteria

Inference Rules The system includes inference rules suggested by physicians. Example: If the cancer stage is III or IV, then the cancer is invasive.

Ordering of Tests The system chooses the ordering of tests that reduces their expected total cost After getting the results of the first test, it revises the ordering of the remaining tests The ordering of tests is based on the test costs, number of trials that require each test, and structure of eligibility criteria

Adding patients Selecting clinical trials Entering initial data Entering medical data Revising medical data Entering Patients’ Data

Adding patients Selecting clinical trials Entering initial data Entering medical data Revising medical data Adding Patients Add a new patient Find an old patient

Adding patients Selecting clinical trials Entering initial data Entering medical data Revising medical data Selecting Clinical Trials Choose candidate trials View all available trials

Adding patients Selecting clinical trials Entering initial data Entering medical data Revising medical data Entering Initial Data Answer initial questions Change previous answers

Adding patients Selecting clinical trials Entering initial data Entering medical data Revising medical data Entering Medical Data Enter medical-test results View eligibility decisions

Experiments Twelve breast-cancer trials at the H. Lee Moffitt Cancer Center Retrospective data from 187 patients Current data from 74 patients

Finding Eligible Patients Retrospective data from 187 patients Missing Data Clinical Trial Same Matches New Matches

Missing Data Clinical Trial Same Matches New Matches Finding Eligible Patients Current data from 74 patients

Conclusions The system can help to identify eligible patients and increase the number of trial participants It can potentially reduce the cost of medical tests related to eligibility decisions

Future Work Conduct more experiments Add clinical trials for lung cancer Combine the implemented heuristics with probabilistic reasoning