Cohort-based Clinical Trial Retrieval
Bevan Koopman, Guido Zuccon · Australasian Document Computing Symposium · 2021
Clinical Trials are a critical step for medical advancement; key to success is recruiting eligible patients to a trial. Retrieval methods are used to identify relevant trials given a single patient/query. After careful consideration of the clinical setting, this paper takes a different approach: cohort-based trial retrieval. We consider ranking trials that maximise recruitment opportunities across the whole patient cohort, instead of a single patient. This resolves into optimising a ranking for the whole query set formed by the patient cohort, rather than treating each query independently — and thus considering an evaluation measure based on cohort coverage. We study the adaptation of rank fusion methods and diversity reranking to this problem. Empirically, we show the surprising impact of initial ranking effectiveness (underlying initial retrieval) on cohort coverage when adapting rank fusion methods. We further highlight that devising cohort-aware methods would have a far greater impact on patient recruitment.