When We should be Testing, How often and what to Report

Abstract

This chapter will offer practical suggestions for clinical microbiologists to help establish cost-effective policies for antimicrobial susceptibility testing of bacteria and efficient reporting of information to guide antimicrobial therapy. The cost of antimicrobic therapy greatly exceeds the cost of the bacteriology laboratory. Therefore, the combined efforts of the microbiologist, the pharmacist and the medical staff should be focused on producing information that reduces antimicrobic cost.¹ Procedures will be recommended here to minimize the production of clinically unnecessary information and the reporting of excessive data that is potentially confusing to clinicians. The practices described are based on over 30 years of cooperative effort between the Microbiology Laboratory, Pharmacy Services and the Division of Infectious Diseases, Department of Medicine at Hartford Hospital. These efforts have reduced the percentage of antimicrobic cost in our pharmacy budget to about 15%. Nationally it is more typical for 30–50% of pharmacy budgets to be consumed by antimicrobic use.^2,3 Further, about 20,000,000 bacterial isolates are subject to antimicrobial susceptibility testing in the nation’s laboratories annually.⁴ Compared to one other major center of comparable size and volume of testing we perform one fifth the number of antimicrobial susceptibility tests (Table 1). This results largely from controls that we have imposed on the quality of specimens and the extent of testing that is performed.⁵ Studies have shown that the cost for microbiologic processing in our laboratory is lower than that for conventional processing without controls.⁶