Methods: Hospitalized patients with laboratory confirmed infection of E. coli, K. pneumoniae, P. aeruginosa and A. baumannii from specific infection sites (blood, respiratory, urine, other) were identified in electronic health records from Premier Healthcare Alliance database from 2009 to 2013. Two cohorts (Resistant and Susceptible) were identified based on antibiotic susceptibility. Antibiotic usage, including combination regimens, was classified into three time periods: Prior (before index date of infection); Empiric (from index date to day plus 3), or BAT (day 4-10). Treatments received during Empiric period and BAT periods by >=3% of patients for each bacterium and site of infection were described for each cohort.
Results: Ten of 124 treatment patterns treated at least 3% of patients in BAT period and accounted for 24% of CR and 48.6% of CS A. baumannii blood stream infections (BSI) in the same period. Similarly, 9 of 207 treatment patterns with >=3% usage treated 22.5% of CR and 51.5% of CS A. baumannii respiratory infections. Usage of carbapenems in BAT period (17% to 38%) did not change from its empiric period (17% to 38%) for CR A. baumannii and P. aeruginosa infections, but increased for CR of K. pneumoniae (by 11% to 44%) and E. coli infections (by 46% to 100%), and for all CS infections (by 20% to 108%). Colistin or polymyxin B (polymyxin) was used in 30% CR of A. baumannii BSI but 0% of CR E. coli BSI in BAT period. Polymyxin usage in BAT significantly increased from Empiric period for all CR infections (by 37% to 420%) except E. coli from blood or urine. Polymyxins were rarely used (0 to 2.8%) in CS infections.
Conclusion: CR was highly dependent on bacterial species and infection site. Antibiotic BAT was mostly combination treatment and highly variable but frequently included carbapenems. Polymyxin use was more common in A. baumannii BSI but not for other infections. No standard antibiotic regimen exists for CR Gram-negative infections.
E. Ogura, SHIONOGI & CO., LTD.: Employee , Salary
J. C. Arjona Ferreira, SHIONOGI INC.: Employee , Salary
M. Ariyasu, SHIONOGI & CO., LTD.: Employee , Salary
T. Sawada, SHIONOGI & CO., LTD.: Employee , Salary
G. Magee, None
T. D. Nagata, SHIONOGI & CO., LTD.: Employee , Salary
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