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

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.

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.

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).

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.].