PIN24 THE ECONOMIC IMPACT OF METHICILLIN RESISTANCE IN STAPHYLOCOCCUS AUREUS BACTEREMIA IN KOREA


A166 Abstracts

parison purposes, the mortality rate of all inpatients with S. aureus
infections was 7.3%. Patients with S. aureus cSSSIs were older
(mean age 54 years vs. 46 years for the comparison group) and
were more likely to have congestive heart failure, diabetes with
chronic complications and bacteremia/septicemia. Relative to the
comparison group, patients with S. aureus cSSSIs had significantly
(P < 0.0001) longer mean length of stay (9.7 vs. 4.4 days) and
higher average costs per stay ($16,941 vs. $9,154). After con-
trolling for potentially confounding factors, the excess mean costs
associated with S. aureus cSSSIs were estimated to be $3,396.
CONCLUSION: Our findings suggest that the clinical and eco-
nomic burden of complicated skin and skin structure infections
(cSSSIs) due to Staphylococcus aureus among hospitalized
patients is substantial.

PIN22
IMPACT OF S. AUREUS INFECTIONS ON EXPENDITURES AND
LENGTH-OF-STAY IN U.S. HOSPITALS
Noskin G1, Rubin R2, Schentag J3, Kluytmans J4, Hedblom E5,
Jacobson C5, Smulders M6, Gemmen EK7, Bharmal M7
1Northwestern University Feinberg School of Medicine, Chicago, IL,
USA, 2Georgetown University, Washington, DC, USA, 3University at
Buffalo School of Pharmacy, Buffalo, NY, USA, 4Amphia Hospital and
VUmc Medical University, Amsterdam, 4800 RK, The Netherlands,
53M Medical, St Paul, MN, USA, 6Quintiles, Falls Church, VA, USA,
7Quintiles Strategic Research & Safety, Falls Church, VA, USA
OBJECTIVES: Evaluate the incremental impact of S. aureus
infection stays on hospital charges and length-of-stay in U.S.
hospitals in 2003. METHODS: The 2003 Nationwide Inpatient
Sample data were analyzed. Hospital discharges were classified
as either a S. aureus–related infection stay or a non-S. aureus-
related infection stay using a combination of several ICD-9
codes. Incremental effect of S. aureus infection on hospital
charges and length-of-stay was estimated using multivariate
regression models adjusting for hospital fixed effects and patient
variables including age, gender, race, payer, diagnosis-related
grouping and concomitant conditions including diabetes, dialy-
sis and lung disease. RESULTS: S. aureus infection was reported
as a discharge diagnosis for 1.0% of all hospital inpatients, or
389,963 stays, in 2003. S. aureus infection hospital stays were
significantly more likely among male, older patients, stays that
were paid by Medicare, white or non-Hispanics and hospital
stays among individuals with diabetes, lung disease or dialysis.
After adjusting for covariates, the mean incremental impact of
S. aureus infection on hospital charges and length-of-stay was
$37,251 (95% Confidence Interval (CI): $34,678–$39,823) and
8.2 days (95% CI: 7.9–8.5) among all inpatient stays, $40,637
(95% CI: $37,683–$43,591) and 9.2 days (95% CI: 8.8–9.6)
among surgical stays, $83,952 (95% CI: $75,853–$92,052) and
16.8 days (95% CI:15.7–17.9) among invasive cardiovascular
stays, $34,202 (95% CI: $29,612–$38,791) and 9.6 days (95%
CI: 9.0–10.2) among invasive orthopedic stays and $119,292
(95% CI: $106,209–$132,374) and 19.8 days (95% CI:
17.5–22.2) among invasive neurosurgical stays. CONCLUSION:
S. aureus infections present a considerable economic burden to
U.S hospitals. Based on the prevalence of S. aureus infection and
its incremental impact, the total economic impact of S. aureus
among all hospital admissions was estimated at $14.5 billion in
2004 U.S. dollars.

PIN23
DETERMINANTS OF TOTAL HOSPITAL COSTS AMONG
INPATIENTS WITH CANDIDEMIA
Lee SP1, Bunz T2, Gagne JJ2, Maio V2, Goldfarb NI2, Horn DL2,
Swanson R3
1Thomas Jefferson Univeristy, Philadelphia, PA, USA, 2Thomas Jefferson
University, Philadelphia, PA, USA, 3Pfizer Inc, New York, NY, USA
OBJECTIVES: To identify factors associated with total hospital
costs among patients with candidemia in a large, urban, tertiary
care, teaching hospital. METHODS: This retrospective cohort
study examined hospitalizations during calendar years 2004 and
2005 at Thomas Jefferson University Hospital in Philadelphia,
PA, using data from various hospital systems. Candidemia cases
were identified via the microbiological laboratory information
system as those patients with at least one confirmed positive
blood culture for any Candida species at any point during the
study period. Demographic, economic, and clinical data, includ-
ing length-of-stay (LOS), payer types, total costs, and Diagnosis
Related Group (DRG) assignments were collected from the hos-
pital cost accounting system. Pharmacy data (i.e. medications
administered and associated costs) were retrieved from the phar-
macy electronic information system. A multivariate regression
analysis, using the natural logarithm of total hospitalization
costs as the dependent variable, was conducted. Independent
variables included demographic information, relative DRG
weights, and Candida species. RESULTS: Among 68,526 total
hospitalizations during the study period, 287 cases were con-
firmed positive for candidemia. The mean age of cases was 58
years, 52% were female, and 60% were Caucasian. The mean
LOS was 43.3 days and the average inpatient cost for candidemia
cases was $130,759 (SD = $116,560; median, $97,869). The
most common Candida species was C. albicans (n = 127; 44%).
The most commonly used antifungal treatment was fluconazole
(N = 176, 61%). Age, and relative DRG weights (p < 0.05) were
significantly positively correlated with total hospital costs. Older
patients with higher relative DRG weights were associated with
the higher total costs. Race, gender, and marital status were not
associated with total costs. CONCLUSION: Relative DRG
weights, as well as age are associated with total hospital costs
among patients with candidemia. Candidemia is expensive to
treat and results in lengthy hospital stay. Early detection and
treatment may significantly reduce resource use as well as
improve outcomes.

PIN24
THE ECONOMIC IMPACT OF METHICILLIN RESISTANCE IN
STAPHYLOCOCCUS AUREUS BACTEREMIA IN KOREA
Park EJ1, Lee EK2, Chae S3
1Korea Institute for Health and Social Afffairs, Seoul, South Korea,
2Sookmyung Women’s University, Seoul, South Korea, 3Korea Institute
for Health and Social Affairs, Seoul, South Korea
OBJECTIVES: The objective of this study is to examine the eco-
nomic outcome of Methicillin resistance in Staphylococcus
aureus bacteremia in Korea, where MRSA is endemic in major-
ity of hospitals. METHODS: We conducted retrospective case-
control study of patients admitted to three university-based
teaching hospitals in Seoul, Korea in 2005. Cases were defined
as patients with Methicillin-resistant S. aureus (MRSA) bac-
teremia and controls were Methicillin- susceptible S. aureus
(MSSA) bacteremia selected according to a priori matching cri-
teria. 58 cases and 58 controls were identified. Hospital charges
were collected from hospitals’ billing system. RESULTS: The
median hospital charge after the development of bacteremia was
higher for cases with MRSA bacteremia ($8245) than for con-
trols with MSSA bacteremia ($6569). The median hospital



A167Abstracts

charge for pharmaceuticals of MRSA bacteremia patients was
$2411 and that of MSSA bacteremia patients was $1289. The
median length of hospitalization after the development of MRSA
patients who survived was 32.5 days and that of MSSA bac-
teremia control patients who survived was 18 days. CONCLU-
SION: Antibiotic resistance in Staphylococcus aureus bacteremia
increased direct medical cost by 26%. The results of this study
indicate that the MRSA infection is associated with increased
medical cost and prolonged hospital stay.

PIN25
DIRECT COSTS OF ANEMIA AMONG PATIENTS TREATED
WITH ZIDOVUDINE
Curkendall S1, Doan QV2, Everhard F3, Richardson J1, Emons MF2
1Cerner, Vienna, VA, USA, 2Cerner, Beverly Hills, CA, USA, 3Gilead
Sciences, Foster City, CA, USA
OBJECTIVES: Zidovudine (ZDV) use has been shown to be
associated with anemia. Our objective was to assess the impact
of anemia on medical resource use and cost in patients treated
with a ZDV-containing HAART regimens. METHODS: Case-
control study using HIV Insight, which contains medical chart
data from 21 US HIV care centers. ZDV-naïve patients who
began a ZDV-containing HAART regimen on any date from
January 2000 to June 2004 were assessed for baseline anemia
(Hb < 11 g/dL). Those without anemia (N = 529) were followed
through June, 2005 or until they had anemia or changed to a
non-ZDV-containing regimen. Those with anemia (N = 69) were
followed until anemia worsened (drop ≥ 1.0 g/dL). Patients with
an incident anemia event (initiating or worsening) with ≥12
months of follow-up were selected as cases. Controls were
matched on baseline anemia, CD4 < 350, gender and time
period. Medical resource use was tabulated during the 1-year
post anemia period. Costs were estimated for health care encoun-
ters using external data for prices expressed in 2006 $US.
RESULTS: Cases included 70 patients with anemia (57 initiat-
ing, 13 worsening.) Cases had greater use of medical resources
than controls: 9.2 vs 5.0 (P < 0.001) office visits per year, 33%
vs 3% hospitalized (P < 0.001), 21% vs 3% treated with EPO
(P = 0.001) and 7% vs 0% (P = 0.058) with a transfusion. Cases
had higher average annual costs than controls; $37,124 vs
$25,141 (P = 0.002). Cost components included EPO $1,369 vs
$181 (P = 0.002), antiretrovirals $18,299 vs $19,837 (P =
0.461), other drugs $12,488 vs $3,763 (P = 0.005) and hospital
stays, $3,114 vs $169 (P < 0.001). CONCLUSION: Patients
treated with ZDV who experienced anemia required significantly
more medical care and reported higher medical cost than patients
without anemia.

PIN26
IMPACT OF HIV AND HCV CO-INFECTION ON
HOSPITALIZATION AND RESOURCE USE AMONG
HEMOPHILIA ENROLLEES IN COMMERCIAL HEALTH PLANS
Tencer T1, Friedman H2, Li-McLeod J3, Johnson KA1
1University of Southern California, Los Angeles, CA, USA, 2Analytic
Solutions, LLC, New York, NY, USA, 3Baxter BioScience, Westlake
Village, CA, USA
OBJECTIVES: Determine the economic impact and resource uti-
lization of adult HIV and HCV co-infected hemophilia patients
in a managed care population in the United States. METHODS:
Retrospective claims database analysis from 1/97 to 4/04.
Patients continuously enrolled for at least 6 months and >18
years of age were included. Hemophilia patients were identified
using ICD-9CM, HCPCS, and NDC codes. Four cohorts for
analysis were established: Hemophilia only Hemophilia + HIV,
Hemophilia + HCV, Hemophilia + HIV + HCV. The main out-

comes of study were costs associated with all pharmacy and
medical claims, inpatient hospitalizations (frequency and length
of stay) and office visit distribution by physician specialty.
RESULTS: Annual cost of care was $85,616 for the hemophilia
only cohort, $99,180 for the HIV cohort, $105,676 for the HCV
cohort and $129,889 for HIV/HCV co-infected cohort in 2004
dollars. Clotting factor accounted for approximately 70–81% of
total costs. The Hemophilia only, HCV, HIV, HIV/HCV infected
hemophilia cohorts had prescription drug costs of $2,341,
$8,867, $6,256 and $12,060, respectively. Approximately 17%
of hemophilia only, 19% of HCV, and 27% of the HIV/HCV
cohorts were hospitalized during the study period (p = 0.45).
Hospitalizations that were hemophilia related accounted for
43% of total hospitalizations for the hemophilia only cohort and
16% for the HIV/HCV cohort (p = 0.30). No significant differ-
ence in inpatient length of stay was found. There was a differ-
ence in the mean number of office visits among the cohorts (p =
0.022) with the HIV/HCV cohort having more visits than the
hemophilia only group, 18.3 vs. 7.3, respectively (p = 0.05).
CONCLUSION: Although we were not able to control for sever-
ity, the presence of HIV and HCV co-infection in hemophiliacs
is associated with an increase in annual costs by up to 52%.
Increased clotting factor use and prescription drug costs in the
virally infected groups account for most of the increase in costs.

PIN27
USING DECISION SIMULATION MODEL TO EVALUATE THE
COST EFFECTIVENESS OF ENTECAVIR COMPARED TO
ADEFOVIR THERAPY IN LAMIVUDINE REFRACTORY
CHRONIC HEPATITIS B (CHB) PATIENTS: ANALYSES FROM 
A US PAYER PERSPECTIVE
Yuan Y1, Iloeje U2, Parry D3, Hay JW4, Zammit D5
1Bristol Myers Squibb International Corporation, Plainsboro, NJ, USA,
2Bristol Myers Squibb Company, Wallingford, CT, USA, 3Bristol Myer
Squibb Company, Hounslow, Middlesex, UK, 4University of Southern
California, Los Angeles, CA, USA, 5Bristol-Myers Squibb, Braine
l’Alleud, Belgium
OBJECTIVES: To estimate the long-term health and economic
impact of managing CHB with entecavir instead of adefovir
treatment in the US, based upon projected clinical benefits from
HBV DNA reduction observed in trials. METHODS: We took
the perspective of a comprehensive payer responsible for all
direct health care expenditures. A decision simulation model was
developed to consider a hypothetical cohort of 1000 lamivudine
refractory CHB patients. Multivariate-adjusted relative risks for
five HBV DNA categories were derived from the published
R.E.V.E.A.L.-HBV study. These results were applied to the
patients with simulation of their HBV DNA data derived from
summary statistics reported in separate entecavir and adefovir
clinical trials. Entecavir and Adefovir daily costs were assumed
$20.52 and $19.11 based on the wholesale acquisition prices.
Life expectancy estimates, direct medical cost of and utility
scores for different phases of CHB were estimated from pub-
lished US specific data. Viral resistance due to treatment was
included. RESULTS: Entecavir was superior to adefovir for the
mean reduction in serum HBV DNA by PCR assay (log10
copies/mL) adjusted for lamivudine effect, with reductions of
4.97 versus 4.00, respectively. More patients reached unde-
tectable viral load level with entecavir than adefovir treatment
at Week 48 (19.5% vs 9.6%). In the reference case, for 1000
patients aged 40 years, compared with adefovir, ten years of ente-
cavir treatment avoided 25 compensated cirrhosis, 3 decompen-
sated cirrhosis, and 15 HCC, resulting in 0.235 quality-adjusted
life year (QALY) gain at an incremental cost of $2563 per patient
(3% discounted). The incremental cost of using entecavir was