Skin infections and antibiotic stewardship: analysis of emergency department prescribing practices, 2007-2010.

INTRODUCTION: National guidelines suggest that most skin abscesses do not require antibiotics, and that cellulitis antibiotics should target streptococci, not community-associated MRSA (CA-MRSA). The objective of this study is to describe antimicrobial treatment of skin infections in U.S. emergency departments (EDs) and analyze potential quality measures.

METHODS: The National Hospital Ambulatory Medical Care Survey (NHAMCS) is a 4-stage probability sample of all non-federal U.S. ED visits. In 2007 NHAMCS started recording whether incision and drainage was performed at ED visits. We conducted a retrospective analysis, pooling 2007-2010 data, identified skin infections using diagnostic codes, and identified abscesses by performance of incision and drainage. We generated national estimates and 95% confidence intervals using weighted analyses; quantified frequencies and proportions; and evaluated antibiotic prescribing practices. We evaluated 4 parameters that might serve as quality measures of antibiotic stewardship, and present 2 of them as potentially robust enough for implementation.

RESULTS: Of all ED visits, 3.2% (95% confidence interval 3.1-3.4%) were for skin infection, and 2.7% (2.6-2.9%) were first visits for skin infection, with no increase over time (p=0.80). However, anti-CA-MRSA antibiotic use increased, from 61% (56-66%) to 74% (71-78%) of antibiotic regimens (p<0.001). Twenty-two percent of visits were for abscess, with a non-significant increase (p=0.06). Potential quality measures: Among discharged abscess patients, 87% were prescribed antibiotics (84-90%, overuse). Among antibiotic regimens for abscess patients, 84% included anti-CA-MRSA agents (81-89%, underuse).

CONCLUSION: From 2007-2010, use of anti-CA-MRSA agents for skin infections increased significantly, despite stable visit frequencies. Antibiotics were over-used for discharged abscess cases, and CA-MRSA-active antibiotics were underused among regimens when antibiotics were used for abscess. [West J Emerg Med. 2014;15(3):282-289.].