Association of length of stay and total hospital charges with antimicrobial regimen changes

The association of changes in antimicrobial therapy with length of stay and total hospital charges in a 600-bed general medical hospital was studied. Changes in antimicrobial regimens were examined in three diagnosis-related groups (DRGs): DRG 79 (respiratory infections and inflammations, age greater than 69 years, and/or secondary diagnosis), DRG 89 (simple pneumonia and pleurisy, age greater than 69 years, and/or secondary diagnosis), and DRG 416 (septicemia, age greater than 17 years). These changes were defined as follows: (1) switching from one drug or drug combination to another, (2) adding one or more drugs to a regimen, or (3) discontinuing one drug of a multiple-drug regimen. Variables examined for association with these changes were length of hospital stay and pharmacy, antimicrobial, intravenous therapy, and hospital charges. In DRGs 79 and 89, changes in antimicrobial regimens were associated with significantly longer hospital stay and significantly higher pharmacy, antimicrobial, intravenous therapy, and total hospital charges. In DRG 416, changes in antimicrobial regimens were not associated with higher charges or longer stay. Significant differences among DRGs were found with respect to the types of changes, with more changes from broad- to narrow-spectrum coverage occurring in DRGs 89 and 416 than in DRG 79. At this institution, patients whose antimicrobial regimens were changed had significantly longer hospital stays and higher charges in two of three DRGs.