BOLON M, BRODIE S, GOLD H, CARMELI Y; Interscience Conference on Antimicrobial Agents and Chemotherapy (42nd : 2002 : San Diego, Calif.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2002 Sep 27-30; 42: abstract no. K-1350.

Beth Israel Deaconess Med Ctr, Boston, MA.

BACKGROUND: Case-control analyses of resistant vs. susceptible isolates have implicated FQ as a strong risk factor for FQ-R gram-negative organisms. We suspect this methodology may overestimate this risk. METHODS: In a case-case-control study, 84 cases with FQ-R and 578 cases with FQ-susceptible (FQ-S) E. coli or K. pneumoniae were compared with 608 hospitalized controls without enterobacteriaceae isolates. Data on demographics, hospital events, procedures, and antibiotic treatment were collected. The effect of exposure to FQ was examined in parallel multivariable (MV) analyses. In order to compare with previous estimates, case-control studies of risks for FQ-R in these organisms were identified by Medline search and results were pooled using a random-effect model. RESULTS: 1270 patients were included (mean age 65; 41% male). FQ-R and FQ-S cases were more likely than controls to have an ICU stay, to have comorbidities, and to receive certain antibiotics. On univariate analysis, exposure to FQ was significantly associated with FQ-R (OR 3.2; p < 0.01) and prevented FQ-S (OR 0.18; p <.01). MV model for FQ-R included: FQ use (OR 2.0, p = 0.03); ICU stay (OR 2.7, p < 0.01); cardiovascular disease (OR 2.2, p < 0.05); vancomycin use (OR 3.2, p < 0.01); and aminoglycoside use (OR 3.7, p < 0.01). MV model for FQ-S included: FQ use (OR 0.1, p < 0.01); ICU stay (OR 3.3, p < 0.01); cephalosporin use (OR 0.5, p < 0.05); and metronidazole use (OR 1.9, p < 0.05). To compare with previous case-control studies of the risk of FQ exposure upon FQ-R, OR from 7 studies were pooled: pOR 28, [13.2-60.8]. Had we performed standard case-control analysis, our univariate results would have led to an OR 19 and the MV model to an OR 16. CONCLUSIONS: FQ use is a risk factor for the isolation of FQ-R E. coli and K. pneumoniae; however, previous studies have exaggerated the magnitude of this risk by 10 fold. This case-case-control analysis demonstrates the biases resulting from traditional case-control studies using patients with susceptible isolates as reference.

Publication Types:

• Meeting Abstracts

Keywords:

• Anti-Bacterial Agents
• Case-Control Studies
• Enterobacteriaceae
• Fluoroquinolones
• Humans
• Intensive Care Units
• Male
• Risk Factors
• United States
• utilization

Other ID:

• GWAIDS0027094

UI: 102266718

From Meeting Abstracts