6124 Background: Nausea/vomiting is a significant toxicity in the treatment of lung cancer, but barriers exist to the delivery of prophylaxis. We studied compliance and predictors of prophylactic antiemetics with chemotherapy in this setting. Methods: We used a Texas state registry of clinical data linked with Medicare claims from 2001-2007. Our study population was incident lung cancers treated with platinum agents within 12 months of diagnosis. To define guideline-adherent care, we assessed compliance to the American Society of Clinical Oncology recommended prophylactic agents dexamethasone and a 5-HT3 antagonist. Adherence was scored as a binary variable and defined as administration within 24 hours of the first day of the first cycle of chemotherapy. We utilized a logistic regression model to evaluate the role of the following factors in predicting adherence: concurrent radiation therapy (RT), race (black vs. white), histology (small cell vs. non-small cell), rural location, Charlson Comorbidity Index (CCI), household income (by quartiles [Q]), education, and treatment year (binary). Results: Of 31,762 patients in the database, 5155 patients met the above criteria. The adherence rate to dexamethasone and 5-HT3 antagonists increased over time, from 51.5% in 2001 to 71.6% in 2007. Patients treated in the years 2005-2007 were 1.739 times more likely to be adherent to prophylaxis than were those from 2001-2004. Variables that predicted adherence (adjusted odds ratio [OR], 95% confidence interval [CI]) were: age (OR=1.013, CI [1.001, 1.026]), treatment year (OR=1.756, CI [1.548, 1.991]), race (black vs. white OR=0.684, CI [0.548,0.853]), median income (higher vs. lower OR=1.83 [Q2 vs. Q1]; OR=1.296 [Q3 vs. Q1]; OR=1.496 [Q4 vs. Q1]), CCI (1+ vs. 0, OR=0.613, CI [0.530,0.709]), and concurrent RT [yes vs. no OR=1.358, CI [1.197,1.541]). Conclusions: Compliance with guidelines for prophylactic antiemetics is suboptimal, but increasing over time. Several characteristics predict for improved adherence, including white race, median income, advanced age, and the receipt of concurrent RT. These findings highlight substantial economic disparities in supportive care of lung cancer in the state of Texas.