Class of 2011 Abstract / OBJECTIVES: To assess the role of patient, payer, clinical and disease-related factors in charges and mortality among adult inpatient cases of polycythemia vera in the United States from 2004 to 2008. METHODS: This retrospective cohort study utilized hospital discharge records from the Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) five consecutive years from 2004 to 2008. RESULTS: There were a total of 156,490 episodes of care involving polycythemia vera between 2004 and 2008. Average age upon admission was 65.94 years (±16.03), with 56% of cases being male (n=87,662). The mean length of stay was 5.14 days (±5.31) and inpatient mortality occurred in 3.1% of cases (n=4,927). The mean number of procedures performed was 1.43 (±2.08) and the mean number of diagnoses on record was 9.56 (±3.86). Charges for each episode of care averaged $32,620 (±42,801), summing to a national bill of $5.02 billion (2010 dollars) over the five-year time horizon. Higher charges were associated with longer length of stay, larger hospital bed size, urban hospital location, teaching status, increased number of diagnoses and procedures, private payer, Western U.S. region, and higher income bracket. Increased mortality was associated with increased age, increased number of diagnoses and procedures, self pay, payer other than Medicare, Medicaid, private or self, and the comorbidities of congestive heart failure, coagulopathy, and fluid/electrolyte disorders. CONCLUSION: Polycythemia vera is associated with considerable burden of illness.