OBJECTIVES: The objective of this study was to estimate the national prevalence, mortality, and cost of CLABSIs.  CLABSI prevalence in ICUs has been studied in a few hospitals, and some states mandate reporting selected blood stream infections (BSI), but these laws are neither universal nor consistent.  This study estimates the hospital-wide prevalence, cost, and mortality of CLABSI-associated discharges for all US community hospitals.  Hypotheses are that CLABSI prevalence and mortality are increasing and cost is unchanged.   METHODS: Data for the study was extracted from the AHRQ HCUP National Inpatient Sample (NIS) database for 2002 and 2006.  CLABSI was defined as a discharge with an ICD9-CM procedure code for a central line procedure (38.92, 38.93, and 38.95) and an ICD9-CM diagnosis code for a BSI (24 codes).  SAS Proc Surveyreg was used to estimate (log of) cost, and Surveylogistic was used to estimate mortality and CLABSI prevalence.  NIS weights were used to make national estimates, charges were adjusted using cost-to-charge ratios, and costs were adjusted to 2006 US dollars using the hospital service CPI.  RESULTS: Average cost of a CLABSI-related hospitalization was $31,879 in 2006 dollars.  Presence of CLABSI had a positive significant effect on cost (0.128, p<0.001), as did the number of procedures (0.125, p<0.001) and LOS (0.034, p<0.001) while being female had a significant negative effect (-0.027, p<0.001).  The time variable was not significant (-0.056, p=0.052).  OR for CLABSI increased over time (1.196, p<0.001) when controlling for gender, LOS, number of procedures, liver disease, and renal failure.  For mortality significant ORs (p<0.001) were time (0.761), female (0.875), LOS (0.982), age (1.026), number of procedures (1.204), liver disease (1.814), and CLABSI (2.348).  CONCLUSIONS: CLABSI-related hospital mortality in the US is decreasing as is the cost of treatment.  However, the prevalence of CLABSI is increasing.