109 Background: Increasing costs of cancer drugs underscore the importance of EA, which convey key information about the relative costs and benefits of new interventions. Although guidelines for abstracts exist for phase I, II, and III oncology trials, similar recommendations for EA are lacking. Our objectives were to 1) identify items considered to be essential for EA abstracts; 2) evaluate the quality of EA abstracts submitted to ASCO, ASH, and ISPOR meetings; and 3) propose guidelines for future reporting. Methods: Health economic experts were surveyed and asked to rate each of 24 possible EA elements on a 5-point Likert scale. A scoring system for abstract quality (0=poor and 100=excellent) was devised based on EA elements with an average expert rating ≥ 3.5. All EA abstracts from ASCO (‘97–‘09), ASH (‘04–‘09) and ISPOR (‘97–‘09) were reviewed and assigned a quality score. Results: Of 99 experts surveyed, 50 (51%) responded. Characteristics of respondents: average age = 53; male = 78%; US / Europe / Canada = 54% / 28% / 18%. A total of 216 abstracts were reviewed: ASCO 53%, ASH 14% and ISPOR 33%. Median quality score was 75 (range 48 to 93), but notable deficiencies were observed. For instance, the cost perspective of the EA was reported in only 61% of abstracts, while the time horizon was described in only 47%. An association was seen between year of presentation and overall quality of abstracts (p=0.001), with those from recent years demonstrating better quality scores. There were also disparities in quality scores among EA of different cancer sites (p=0.005). Conclusions: Quality of EA abstracts for oncology has improved over time, but there is room for improvement. Abstracts may be enhanced using guidelines derived from our survey of experts (see table). [Table: see text]