eTACTS: an Eligibility Tag Cloud-based Clinical Trial Search Engine

We present eTACTS, a Web search engine that allows users to select eligibility tags to filter clinical trial search results. A controlled vocabulary of frequent tags is automatically mined by cross-processing clinical trial eligibility criteria and used to index all the trials in ClinicalTrials.gov. After an initial search, these tags are presented to the users as an interactive tag cloud for iterative reduction of resulting trials. The cloud is dynamically updated at every tag selection with respect to the tag frequency and co-occurrences in the remaining trials. Introduction Free-text eligibility criteria are often not processed by clinical trial search engines. Nevertheless, they contain details about eligible research volunteers that should be taken into account to provide meaningful and limited-size results to the end users. To this aim we developed eTACTS, a novel interactive retrieval framework using common eligibility tags to dynamically filter clinical trial search results.