Background: The increasing use of antimicrobial drugs is resulting in enorm
ous hospital expenditures. Careful assessment of inappropriate prescribing
and a search for more cost-effective treatment strategies are urgently requ
ired. Comparisons between hospitals should help identify areas of inappropr
iate prescribing as well as effective drug use programs, but such analyses
may be severely biased if the impact of different case-mixes is not recogni
zed.
Patients and Methods: We studied antimicrobial usage and expenditures at fo
ur state university hospitals in southwestern Germany and assessed the sign
ificance of differences between hospital services after adjustment for pati
ent variables. A prevalence survey was done with review of 2,254 charts of
patients admitted to the surgical, medical and pediatric services to obtain
information on antimicrobial drug prescription and expenditures in the wee
k preceding the survey.
Results: According to pharmacy data for the year 1994, maximal differences
between these hospitals in the antibiotic costs per patient-day were 1.9-fo
ld (surgical services), 1.5-fold (medical services), and 1.6-fold (pediatri
c services). In a multivariate analysis, adjusted antibiotic prescription p
revalence rates did not differ for medical and pediatric service patients,
but did differ for surgical service patients (p = 0.03), Similarly, adjuste
d expenditures per patient-week differed significantly between hospitals fa
r surgical service patients (p = 0.001), but only marginally for medical(p
= 0.14) and pediatric (p = 0.05) service patients. The adjusted difference
in expenditures between surgical departments was as Large as 2.8-fold (95%
CI 1.8 to 4.3) and was primarily related to preferential use of expensive i
v antimicrobial drugs.
Conclusion: In two hospitals, Lowest expenditures in either surgery or medi
cine were associated with active antimicrobial drug use programs suggesting
an impact of these programs on drug use and expenditures Limited to these
services. The identification of such Large patient-mix unrelated difference
s in antimicrobial usage and expenditures offers opportunities for quality
improvements and cost reduction.