Learning the Burden of C diff on the Health Care System through Meta-Analysis

Clostridiodies difficile (C diff) can place a large burden on the health care system, however, such estimates should be interpreted with caution, according to a study published in JAMA Network Open.

Investigators from the University of Iowa conducted a meta-analysis and literature review of 86 studies in order to quantify the incidence of C diff and its related hospital lengths of stay in the United States. The team searched through 6 databases for studies published between 2000 and 2019 that examined C diff and its associated lengths of stay.

“We acknowledge that the literature has diverse studies with variable outcomes,” study author Alexandre Rodrigues Marra, MD, told Contagion®.

The study authors believed their analysis was important and could inform investments in prevention and treatment interventions. They said that while prior studies have examined the effects of C diff infections on length of stay, mortality, and treatment costs, the studies do not often take into account infection severity. Therefore, these past studies may have overestimated the attributable outcomes, the study authors wrote.

Ultimately, they only collected incidence data from multicenter studies that included at least 5 sites. Information about lengths of stays were included only if the original investigation considered post-infection length of stay or used method to account for time to infection among the C diff patients compared to patients without the infection. The study authors also noted that they excluded data from long-term health care facilities.

There were 13 studies that evaluated hospital-onset C diff incident cases per the same denominator, which was 10,000 patient-days. Marra said the study authors wanted to avoid comparisons that used alternative denominators. For analysis of length of stay, the investigators only used studies that implemented advanced statistical methods, such as propensity score matching, Marra said. Therefore, there was considerable variability among the C diff incidence rates and the length of stay calculations.

Nonetheless, the study authors were able to determine that the incidence of C diff infection in the United States is approximately 8.3 cases per 10,000 patient-days. The excess hospital length of stay related to C diff infection ranged from 3 to 21 days, they added.

“Thus, our systematic literature review and meta-analysis quantified the burden of C diff infection in the United States, without overestimating the burden as has been done in past studies that used inferior methods,” Marra said.

The study authors recommend further investigation into this topic, to inform future evaluations of C diff prevention and treatment interventions, they wrote. They also admitted that one of their limitations was using only United States studies published in English, though they said they were primarily hoping to examine the burden in the US.

“It is a good opportunity to stay tuned that C diff infection definition is not only problematic but also complex, and variation in C diff infection incidence may be in part to advances in diagnostic technology as well as variations in diagnostic practices among different U.S. institutions,” Marra concluded. “An understanding of the incidence and impact of C diff infection can promote investments in prevention and treatment interventions.”