Differences in antimicrobial susceptibility among hospitals in an integrated health system

We evaluated the differences in antimicrobial susceptibility among hospital s in three different integrated healthcare systems. Each system provided an tibiogram-susceptibility reports from representative hospitals. Reports wer e analyzed for statistically significant differences between hospitals in a given system for nine important organisms. We found numerous significant i nterhospital differences in antimicrobial-susceptibility patterns within he alth systems. For this reason, the practice of combining antibiotic-suscept ibility data into a systemwide antibiogram should be discouraged.