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Automated Selection of Patients for Clinical Trials. Eugene Fink Lawrence O. Hall Dmitry B. Goldgof Bhavesh D. Goswami Matthew Boonstra Jeffrey P. Krischer. Clinical trials. A clinical trial is an evaluation of a new treatment procedure.
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Automated Selection of Patients for Clinical Trials Eugene FinkLawrence O. HallDmitry B. GoldgofBhavesh D. GoswamiMatthew Boonstra Jeffrey P. Krischer
Clinical trials A clinical trial is an evaluationof a new treatment procedure. When physicians conduct a trial, theyrecruit patients with matching healthproblems and medical histories.
Selection of patients The selection of trial participants isa manual procedure, and physiciansmay miss eligible patients. • Gotay [1991] demonstrated that physicians choose only 39% of the eligible patients • Fallowfield et al. [1997] showed that they choose less than 50% of the eligible patients
Expert system We have developed a system thatautomatically selects prospectivetrial participants.
Outline • Knowledge base • Selection results • Cost reduction
Knowledge base • Tests and questions • Eligibility criteria
Tests and questions The knowledge base includes a list of medical tests. A test descriptionincludes a dollar cost and relatedquestions about a patient’s health. Example Mammogram, $150What is the cancer stage?Does the patient have invasive cancer? Biopsy, $400How many lymph nodes have tumor cells?What is the greatest tumor diameter?
Example AND cancer-stage {II, III} lymph-nodes 3 OR invasive-cancer = NO tumor-diameter 2.5 Eligibility criteria The knowledge base also includeslogical expressions that representeligibility for the available trials.
Selection process The system collects data until it candetermine whether the eligibilityexpressions are TRUE or FALSE. If patient records do not provideenough data, the system identifiesthe required medical tests.
Outline • Knowledge base • Selection results • Cost reduction
Experiments We have used fifteen breast-cancertrials at the Moffitt Cancer Center. • Past data from 187 patients • Current data from 169 patients
Summary The results suggest that the systemcan increase the number of trialparticipants by a factor of three.
Outline • Knowledge base • Selection results • Cost reduction
Medical tests The selection of trial participantsmay require medical tests. • The total cost of tests may depend on their ordering • Finding the right ordering is often a complex problem
Ordering of tests The system chooses the ordering of teststhat reduces their expected total cost. After getting the results of the first test, itrevises the ordering of the remaining tests. The ordering is based on the test costs,number of trials that require each test,and structure of eligibility expressions.
Cost reduction Past data for 187 patients $250 W/O Reordering $200 With Reordering $150 $100 $50 $0 11072 11378 10822
Cost reduction Current data for 169 patients $250 W/O Reordering $200 With Reordering $150 $100 $50 $0 12601 12757 11971
Conclusions We have developed a system thatselects prospective trial participants. • Helps physicians to identify eligible patients • Can increase the number of trial participants • Can reduce the cost of the selection process
Future work • Deploy the system at the Moffitt Cancer Center • Evaluate the satisfaction of physicians and nurses • Add probabilistic reasoning