1021 Background: Adjuvant/Prevention approaches should be designed to have broad applicability for maximum effectiveness. Celecoxib had generated interest as a polyp/colon cancer (CC) preventive agent. We used KPNC electronic data bases to identify consecutive Stage I CC patients and determine their eligibility for NSABP P-3, a polyp prevention study utilizing celecoxib in resected stage I CC. Methods: After IRB approval of both the P-3 study and use of KP data bases for recruitment, we prospectively screened all newly diagnosed CC patients within KPNC (1120 new patients a year) for stage I CC and P-3 eligibility. We identified 121 Stage I CC patients from 9/1/04 to 8/1/05 and using electronic data we screened these patients for 10-year life expectancy and other eligibility criteria. We confirmed each pathology diagnosis and stage by direct review. Results: Without chart review or patient history and exam, we found 65% of the patients were ineligible (IE) for any or multiple reasons. The average patient age was 68.9 years. 133 IE criteria were met by the 121 patients. 32% of patients were IE by age, though for only 11% was age the only criteria met. Other IE included 11% prior invasive CA, 19% coronary disease, 11% sulfa allergy, 8% coumadin usage, 7% prior CVA/TIA, 22% other GI or thrombotic criteria. It is likely that in-person history and examination would increase these IE numbers and reveal other barriers. Conclusions: Population-based automated eligibility analysis may be helpful in evaluating feasibility of chemoprevention and adjuvant trials and more importantly in determining their applicability to the whole population at risk. No significant financial relationships to disclose.