Computerized Clinical Decision Support Systems Decrease Redundant Clostridioides difficile Infection Testing

Clostridium bacteria, computer illustration. Clostridia are spore-forming bacteria that include several human pathogenic species, C. difficile, C. tetani, C. botulinum, C. perfringens, and others. C. difficile is a normal inhabitant of the human intestine, but it can become a pathogen when antibiotics disrupt the normal intestinal flora and allow C. difficile to become established in the colon. A toxin produced by the bacteria can cause diarrhoea, abdominal pain, fever, inflammation of the colon, vomiting and dehydration. C. tetani is the causative agent of tetanus, C. botulinum causes food poisoning botulism, C. perfringens causes gas gangrene and also food poisoning. Clostridium novyi (oedematiens) causes gas gangrene and infectious necrotic hepatitis. The toxins produced by C. tetani (tetanospasmin) and C. botulinum are among the most dangerous known. Some of the clostridia species are involved in the development of bacterial vaginosis.
Researchers conducted a study to determine whether computerized clinical decision support systems decrease the rate of unnecessary testing for Clostridioides difficile infection.

A computerized clinical decision support (CCDS) system was found to decrease the incidence of unnecessary testing for Clostridioides difficile infection (CDI) and was well received by clinicians at both academic and community hospitals. These findings, from a 2-year cohort study, were published in Clinical Infectious Diseases.

This study was conducted at 9 academic and 6 community hospitals in the United States. The CCDS system provided clinicians with ‘hard’ or ‘soft’ stop prompts within the electronic health record (EHR) if duplicate CDI tests were ordered or if patients had received laxatives in the past 48 hours. A hard stop required clinicians to obtain approval to continue CDI test orders, and a soft stop allowed clinicians to continue the order without further approval. The primary outcome was the difference in monthly CDI testing rates pre- and post-CCDS system implementation; secondary outcomes were incident CDIs, antibiotic prescription rates, and clinicians’ opinions regarding the acceptability of the CCDS system.

Among the hospitals included in the analysis, 9 incorporated hard stops  and 4 incorporated soft stops within their respective EHR systems, and 2 used a non-CCDS human interaction best practice advisory (HBPA) stewardship program in which in-person discussions regarding the necessity of CDI test orders occurred among clinician teams).

The researchers found that the rate of CDI testing per 1000 patient-days decreased from 13.1 to 9.9 at hospitals that used hard stops, from 10.5 to 7.6 at hospitals that used soft stops, and from 12.6 to 9.9 at hospitals that used HBPA stewardship programs. After adjustment for covariates, the rate of CDI testing decreased by 33% among the hospitals that implemented a CCDS system with a hard stop (incidence rate ratio [IRR], 0.67; 95% CI, 0.64-0.70; P <.001). Among the hospitals that implemented the CCDS system with a soft stop and those that used HBPA stewardship programs, CDI testing rates decreased by 23% (IRR, 0.77; 95% CI, 0.75-0.79; P <.001) and 21% (IRR, 0.79; 95% CI, 0.72-0.86; P <.001), respectively.

The researchers found that hospitals that implemented the CCDS system with a hard stop more effectively decreased CDI testing rates compared with both those that implemented the system with a soft stop (IRR, 0.88; 95% CI, 0.84-0.91; P <.001) and those used HBPA stewardship programs (IRR, 0.85; 95% CI, 0.77-0.94; P =.002). Additional analysis showed that the effectiveness CCDS systems with a soft stop in decreasing CDI testing rates was similar to that of HBPA stewardship programs (P =.559).

The researchers compared the pre- and-post CCDS intervention periods and found that all interventions significantly decreased the incidence of both CDIs (all P £.002) and antibiotic use (all P <.001). A comparison between all CCDS system interventions showed that those with hard stops were more effective vs those with soft stops (IRR, 0.56; 95% CI, 0.48-0.66; P <.001) and vs HBPA stewardship programs (IRR, 0.57; 95% CI, 0.43-0.76; P <.001) in decreasing CDI rates. In addition, the researchers found that CCDS systems with hard stops were more effective vs those with soft stops (IRR, 0.90; 95% CI, 0.86-0.94; P <.001) in decreasing the rate of antibiotic use, with similar results observed in regard to HBPA stewardship programs vs soft stops (IRR, 0.83; 95% CI, 0.79-0.88; P <.001).

Following the implementation of the CCDS system, most clinicians reported that the CCDS system alerts were not disruptive and that the system helped in reassessing the necessity of CDI testing.

This study was limited by the researchers’ inability to assess the effectiveness of the CCDS system at all sites via in-person visits due to disruptions associated with the COVID-19 pandemic. Other limitations included potential recruitment bias and limited generalizability.

According to the researchers, “this study provides novel insight into the CCDS (system) to further improve [and increase the effectiveness of] diagnostic stewardship interventions. They concluded that “a systems approach based on human factor engineering provides a framework with…elements to support [the development] of effective CCDS interventions.”

Disclosure: Multiple authors declared affiliations with industry. Please see the original reference for a full list of disclosures.


Rock C, Abosi O, Bleasdale S, et al. Clinical decision support systems to reduce unnecessary Clostridoides difficile testing across multiple hospitals.Clin Infect Dis. 2022;ciac074. doi:10.1093/cid/ciac074