UCSF leverages EHR data to track hospital infections

An informatics team at University of California-San Francisco Health has successfully used electronic health records data to identify the source of hospital infections by tracking the movements of more than 85,000 patients admitted to one of its medical centers.

Identifying the source of Clostridium difficile (C. diff) infections in hospitals, bacterium associated with significant morbidity and mortality, is no easy task because of the complex interactions and location changes of patients hospitalized in those healthcare facilities.

Yet, by using time and location stamps entered into the Epic EHR, researchers were able to map 435,000 patient location changes throughout the UCSF Medical Center at Parnassus over a three-year period. Results of the study were published online this week in JAMA Internal Medicine.

“During hospitalization, patients visit many procedural and diagnostic common areas, presenting opportunities for contact with contaminated surfaces,” states the article. “However, these potential exposures are not typically captured in analyses evaluating disease transmission. Electronic health record data allow us to track patients in time and space, but these data are not typically leveraged for infection control quality improvement efforts.”

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Using spatial and temporal mapping, researchers were able to leverage the data to reconstruct where all patients with C. diff infections had travelled in the medical center between 2013 and 2016. What they found was that that one location in the hospital—a CT scanner in the Emergency Department—was a significant source of exposure-related infections.

In fact, patients who entered that scanner within 24 hours after C. diff-positive patients were more than twice as likely to become infected with the bacterium themselves. Specifically, 4 percent of the patients who were considered exposed in the scanner contracted C. diff within two months, while the overall rate of infection for patients who passed through the scanner was 1.6 percent.

“We looked at everywhere those patients went in the hospital,” says Sara Murray, MD, first author of the study and medical director of clinical informatics at UCSF Health. “All that movement represents opportunities for disease transmission.”

Murray contends that traditionally studies examining the spread of C. diff in hospitals have only looked at room sharing with an infected patient. She believes what makes her team’s study novel is that it recognizes the many places in the healthcare setting where infection can potentially happen—although no other sites at the hospital raised concerns regarding C. diff transmission in the three-year study period except one specific CT scanner in the ED.

“There was an association there that we didn’t see anywhere else,” adds Murray, who notes that her informatics team brought that information to the attention of the UCSF Health leadership and infection control committee which implemented cleaning practices for that CT scanner in accordance with those standards already used by other radiology suites. “The data really gave us insight here that we wouldn’t have necessarily had otherwise.”

At the same time, she observes that the EHR database—which includes 16,000 tables—can be challenging to interpret and that her team spent a lot of time validating the data.

“We now know the who, what, when, where and why of what happens to patients in the hospital and there’s a lot of opportunity to leverage EHR data to answer these types of questions,” Murray concludes. “Our hope is that other institutions can take their data and do these kinds of analyses.”

“The electronic health record is a treasure trove of clinical data and insights, but we are just beginning to discover how to unlock its secrets,” said Robert Wachter, MD, chair of the UCSF department of medicine and author of the bestselling book The Digital Doctor: Hope, Hype and Harm at the Dawn of Medicine’s Computer Age. “This study demonstrates the potential to transform patient care when innovative clinicians and technology experts join hands to tackle healthcare’s hardest problems.”