Clinical Pearls & Morning Reports

By Carla Rothaus

Published October 31, 2018


How did the prevalence of health care–associated infections in U.S. hospitals in 2015 compare to that in 2011?

In 2011, the Centers for Disease Control and Prevention conducted a hospital prevalence survey of health care–associated infections and the use of antimicrobial agents with the Emerging Infections Program, a network of 10 state health departments and academic collaborators. A total of 4% of patients had a health care–associated infection. These data were used to generate national estimates of 648,000 patients with 721,800 health care–associated infections in U.S. hospitals in 2011. Magill et al. repeated the survey in 2015 to assess changes in the prevalence of health care–associated infections. Read the latest NEJM Original Article here

Clinical Pearls

Q: What were the most common health care–associated infections in U.S. hospitals in 2015?

A: A total of 12,299 patients in 199 hospitals were surveyed by Magill et al. There were 427 health care–associated infections in 394 patients in the 2015 survey. Pneumonia was the most common infection, followed by gastrointestinal infections (most of which were due to Clostridium difficile [now Clostridioides difficile]), and surgical-site infections.

Q: How did the prevalence of health care–associated infections in U.S. hospitals in 2015 compare to that in 2011?

A: Applying the same definitions of health care–associated infections that had been used in 2011, Magill et al. found that 394 of 12,299 patients in the 2015 survey had one or more health care–associated infections (3.2%; 95% confidence interval [CI], 2.9 to 3.5), as compared with 452 of 11,282 patients (4.0%; 95% CI, 3.7 to 4.4) in the 2011 survey (P<0.001). Results were similar in an analysis that was restricted to 148 hospitals that participated in both surveys. After adjustment for age, time from admission to survey, presence of devices, and status of being in a large hospital, patients in the 2015 survey were 16% less likely to have a health care–associated infection than patients in the 2011 survey (risk ratio, 0.84; 95% CI, 0.74 to 0.95; P=0.005).

Morning Report Questions

Q: Did the prevalence of one or more types of infection decrease in U.S. hospitals in 2015 as compared to 2011?

A: In the study by Magill et al., the percentages of patients with a surgical-site infection or urinary tract infection were lower in 2015 than in 2011. Percentages of patients with pneumonia, gastrointestinal infection (including C. difficile), or bloodstream infection did not differ significantly between 2015 and 2011. Similarly, an analysis of Medicare Patient Safety Monitoring System data showed that, between 2005 and 2013, the percentage of patients with ventilator-associated pneumonia among eligible Medicare patients with selected diagnoses who were undergoing mechanical ventilation remained the same, at approximately 10%. Although the prevention of ventilator-associated pneumonia remains an important goal, the majority of pneumonia events in hospitals in this survey were not ventilator-associated.

Q: How were hospitals recruited for participation in the analysis by Magill et al.?

A: At 10 sites in the Emerging Infections Program (in California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee), general, women’s, and children’s hospitals were recruited in their survey catchment areas. Sites preferentially recruited hospitals that had participated in the 2011 survey. Sites engaged additional hospitals, up to 25 per site, by recruiting from randomly sorted hospital lists stratified according to hospital size (small, <150 beds; medium, 150 to 399 beds; or large, ≥400 beds).

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