Defense Date


Document Type


Degree Name

Doctor of Philosophy



First Advisor

Spencer Harpe

Second Advisor

Ron Polk

Third Advisor

Norman Carroll

Fourth Advisor

Amy Pakyz

Fifth Advisor

Elizabeth Turf

Sixth Advisor

Michael Edmond


Background: The proportion of nosocomial Staphylococcus infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has increased from 22% in 1995 to 63% in 2004. Blood stream infections, more commonly referred to as bacteremias, represented the majority (75.5%) of hospital-onset MRSA cases. The economic impact of Staphylococcus aureus bacteremia merits investigation. Methods: This was a retrospective cohort analysis within Cerner HealthFacts data warehouse. Eligible patients were those who had Staphylococcus aureus bacteremia and were discharged between January 1, 2000, and December 31, 2006. Inclusion criteria include age > 18 years old and onset of infection > 48 hours post admission. The crude association was measured by subtracting the total mean hospital charge for MSSA bacteremia from the MRSA charge. A generalized linear model using a gamma distribution and log link were used to determine the adjusted hospital charge and post-infection length of stay for the MRSA and MSSA groups. Path analysis was used to describe the relationships between infection susceptibility status, LOS and total hospital charge. Results: During the study period, 930 patients meet all the inclusion and exclusion criteria. The overall total hospital charge was $111,636 (MRSA = $121,713, MSSA = $97,307.) The crude difference in mean charge was $24,406. The multivariable model included predicted a MRSA patient would have an increased total charge of $22,889. MRSA had a higher total charge but when patients were more severely ill, MRSA charges decreased while MSSA charges increased. The second multivariable model predicted a MRSA patient would have an increased post-infection LOS of 1.3 days. However, the magnitude of increased post-infection LOS based on pre-infection LOS was different for MRSA and MSSA patients. The path analysis model indicated the direct and indirect effects of susceptibility status on both post-infection LOS and total charge were relatively small. Conclusion: This investigation was the first large multi-center investigation to examine the economic impact of MRSA and MSSA bacteremia. MRSA was associated with a higher total charge and longer post-infection LOS than MSSA patients. The path analysis model analyzed suggests the actually role of infection susceptibility status on post-infection LOS and total charge was minor.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

May 2009