Reductions in Clostridium difficile Infection (CDI) Rates Using Real-Time Automated Clinical Criteria Verification to Enforce Appropriate Testing

Impact of Mandatory Infectious Disease Specialist Approval on Hospital-Onset Clostridioides difficile Infection Rates and Testing Appropriateness

BACKGROUND

Inappropriate Clostridioides difficile testing is common in the hospital setting, leading to potential overdiagnosis of infection when single-step nucleic acid amplification testing is used. The potential role of infectious diseases (ID) specialists in enforcing appropriate C. difficile testing is unclear.

METHODS

At a single 697-bed academic hospital, we performed a retrospective study from 1 March 2012 to 31 December 2019 comparing hospital-onset C. difficile infection (HO-CDI) rates during 3 consecutive time periods: baseline 1 (37 months, no decision support), baseline 2 (32 months, computer decision support), and intervention period (25 months, mandatory ID specialist approval for all C. difficile testing on hospital day 4 or later). We used a discontinuous growth model to assess the impact of the intervention on HO-CDI rates.

RESULTS

During the study period, we evaluated C. difficile infections across 331 180 admission and 1 172 015 patient-days. During the intervention period, a median of 1 HO-CDI test approval request per day (range, 0-6 alerts/day) was observed; adherence by providers with obtaining approval was 85%. The HO-CDI rate was 10.2, 10.4, and 4.3 events per 10 000 patient-days for each consecutive time period, respectively. In adjusted analysis, the HO-CDI rate did not differ significantly between the 2 baseline periods (P = .14) but did differ between the baseline 2 period and intervention period (P < .001).

CONCLUSIONS

An ID-led C. difficile testing approval process was feasible and was associated with a >50% decrease in HO-CDI rates, due to enforcement of appropriate testing.

SEE the DIFFerence: Reducing unnecessary C. difficile orders through clinical decision support in a large, urban safety-net system

BACKGROUND

Clostridioides difficile (C. difficile) is a hospital-acquired infection. Overtesting for C. difficile leads to false positive results due to a high rate of asymptomatic colonization, resulting in unnecessary and harmful treatment for patients.

METHODS

This was a quality improvement initiative to decrease the rate of inappropriate C. difficile testing across 11 hospitals in an urban, safety-net setting. Three best practice advisories were created, alerting providers of recent laxative administration within 48 hours, a recent positive test within 14 days, and a recent negative test within 7 days. The outcome measures were the number of C. difficile tests per 1,000 patient days, as well as the rate of hospital onset C. difficile infection was compared pre- and post-intervention. The process measures included the rate of removal of the C. difficile test from the best practice advisory, as well as the subsequent 24-hour re-order rate.

RESULTS

The number of C. difficile tests decreased by 27.3% from 1.1 per 1,000 patient days preintervention (May 25, 2020-May 24, 2021) to 0.8 per 1,000 patient days postintervention, (May 25, 2021-March 25, 2022), P < .001. When stratified by hospital, changes in testing ranged from an increase of 12.5% to a decrease of 60%. Analysis among provider type showed higher behavior change among attendings than compared to trainees or advanced practice providers. There was a 12.1%, nonsignificant decrease in C. difficile rates from preintervention, 0.33 per 1,000 patient days compared to postintervention, 0.29 per 1,000 patient days, P=.32.

CONCLUSIONS

Using only an electronic health record intervention, we successfully decreased C. difficile orders after 72 hours of admission in a large, safety-net system. Variation existed among hospitals and by provider type.

The future of Clostridioides difficile diagnostics

PURPOSE OF REVIEW

Although the epidemiology of Clostridioides difficile has changed, this organism continues to cause significant morbidity and mortality. This review addresses current and future approaches to the diagnosis of C. difficile disease.

RECENT FINDINGS

Over the last several years, large prospective studies have confirmed that there is no single optimal test for the diagnosis of C. difficile disease. The pendulum has swung from a focus on rapid molecular diagnosis during the years of the ribotype 027 epidemic, to a call for use of algorithmic approaches that include a test for toxin detection. In addition, diagnostic stewardship has been shown to improve test utilization, especially with molecular methods. Advances in testing include development of ultrasensitive toxin tests and an expansion of biomarkers that may be more C. difficile specific. Microbiome research may be leveraged to inform novel diagnostic approaches based on measurements of volatile and nonvolatile organic compounds in stool.

SUMMARY

As rates of C. difficile infection decline, emphasis is now on improving test utilization and a quest for improved diagnostic approaches. These approaches may involve implementation of technologies that improve toxin testing, predict patients likely to have disease and/or a severe outcome, and harnessing research on changes in the microbiome to advance metabolomics.

An emergent infectious disease: Clostridioides difficile infection hospitalizations, 10-year trend in Sicily

Background

Clostridioides difficile is the most common cause of healthcare-associated diarrhoea worldwide and C. difficile infection is an emerging infectious disease. In the US, its rates are monitored trough an active surveillance system, but many European Union member states still lack this, and in Italy no epidemiological data on C. difficile infection are available except for a few single-centre data.

Aim

To provide data on the C. difficile infection incidence in Sicily (the biggest and 5th most populous region of Italy) during a 10-year period.

Methods

We revised all the regional standardized discharge forms between 2009 and June 2019 using the code ICD-9 00845 of the International Classification of Diseases, Ninth Revision Clinical Modification, which refers to C. difficile infection with or without complications.

Results

1139 cases of CDI were identified. 97% were adults with a median age of 73.2 years and a male-to-female ratio of 1:1.4. Female patients were older than males and patients who died were older than patients who did not. The main comorbidities were renal disease, diabetes, pneumonia and hypertension. There were 65 reporting hospitals and 86% of cases were provided by level III and II hospitals. Between 2009 and 2019, the incidence increased 40-fold. 81.5% of cases were reported in Medicine Units, Infectious Diseases Units and long-term care facilities. The mean length of stay was 20 days. Mean case fatality rate was 8.3% over the 10-year period.

Conclusion

Clostridioides difficile infection is a dramatically increasing condition in Sicily. A high-quality surveillance system and shared diagnostic protocols are needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01683-w.

In pursuit of the holy grail: Improving C. difficile testing appropriateness with iterative electronic health record clinical decision support and targeted test restriction

OBJECTIVE

To determine the impact of electronic health record (EHR)-based interventions and test restriction on Clostridioides difficile tests (CDTs) and hospital-onset C. difficile infection (HO-CDI).

DESIGN

Quasi-experimental study in 3 hospitals.

SETTING

957-bed academic (hospital A), 354-bed (hospital B), and 175-bed (hospital C) academic-affiliated community hospitals.

INTERVENTIONS

Three EHR-based interventions were sequentially implemented: (1) alert when ordering a CDT if laxatives administered within 24 hours (January 2018); (2) cancellation of CDT orders after 24 hours (October 2018); (3) contextual rule-driven order questions requiring justification when laxative administered or lack of EHR documentation of diarrhea (July 2019). In February 2019, hospital C implemented a gatekeeper intervention requiring approval for all CDTs after hospital day 3. The impact of the interventions on C. difficile testing and HO-CDI rates was estimated using an interrupted time-series analysis.

RESULTS

C. difficile testing was already declining in the preintervention period (annual change in incidence rate [IR], 0.79; 95% CI, 0.72-0.87) and did not decrease further with the EHR interventions. The laxative alert was temporally associated with a trend reduction in HO-CDI (annual change in IR from baseline, 0.85; 95% CI, 0.75-0.96) at hospitals A and B. The gatekeeper intervention at hospital C was associated with level (IRR, 0.50; 95% CI, 0.42-0.60) and trend reductions in C. difficile testing (annual change in IR, 0.91; 95% CI, 0.85-0.98) and level (IRR 0.42; 95% CI, 0.22-0.81) and trend reductions in HO-CDI (annual change in IR, 0.68; 95% CI, 0.50-0.92) relative to the baseline period.

CONCLUSIONS

Test restriction was more effective than EHR-based clinical decision support to reduce C. difficile testing in our 3-hospital system.

The Impact of Clinical Decision Support Alerts on Clostridioides difficile Testing: A Systematic Review

BACKGROUND

Several studies have investigated the utility of electronic decision support alerts in diagnostic stewardship for Clostridioides difficile infection (CDI). However, it is unclear if alerts are effective in reducing inappropriate CDI testing and/or CDI rates. The aim of this systematic review was to determine if alerts related to CDI diagnostic stewardship are effective at reducing inappropriate CDI testing volume and CDI rates among hospitalized adult patients.

METHODS

We searched Ovid Medline and 5 other databases for original studies evaluating the association between alerts for CDI diagnosis and CDI testing volume and/or CDI rate. Two investigators independently extracted data on study characteristics, study design, alert triggers, cointerventions, and study outcomes.

RESULTS

Eleven studies met criteria for inclusion. Studies varied significantly in alert triggers and in study outcomes. Six of 11 studies demonstrated a statistically significant decrease in CDI testing volume, 6 of 6 studies evaluating appropriateness of CDI testing found a significant reduction in the proportion of inappropriate testing, and 4 of 7 studies measuring CDI rate demonstrated a significant decrease in the CDI rate in the postintervention vs preintervention period. The magnitude of the increase in appropriate CDI testing varied, with some studies reporting an increase with minimal clinical significance.

CONCLUSIONS

The use of electronic alerts for diagnostic stewardship for C. difficile was associated with reductions in CDI testing, the proportion of inappropriate CDI testing, and rates of CDI in most studies. However, broader concerns related to alerts remain understudied, including unintended adverse consequences and alert fatigue.

Clostridium difficile: Diagnosis and the Consequence of Over Diagnosis

Clostridium difficile infection (CDI) is a leading cause of healthcare-associated infections, accounting for significant disease burden and mortality. The clinical spectrum of C. difficile ranges from asymptomatic colonization to toxic megacolon and fulminant colitis. CDI is characterized by new onset of ≥ 3 unformed stools in 24 h and is confirmed by laboratory test for the presence of toxigenic C. difficile. Currently, laboratory tests to diagnose CDI include toxigenic culture, glutamate dehydrogenase (GDH), nucleic acid amplification test (NAAT), and toxins A/B enzyme immunoassay (EIA). The sensitivities of these tests are variable with toxin EIA ranging from 53 to 60% and with NAAT at about 95%. Overall, the specificity is > 90% for these methods. However, the positive predictive value (PPV) depends on the disease prevalence with lower CDI rates associated with lower PPVs.

Notably, the widespread use of the highly sensitive NAAT and its relatively lower clinical specificity have led to overdiagnosis of C. difficile by identifying carriers when NAAT is used as the sole diagnostic method. Overdiagnosis of C. difficile has resulted in unwarranted treatment, possibly attributing to resistance to metronidazole and vancomycin, increased risk for overgrowth of vancomycin-resistant enterococci strains in stool specimens, and increased hospitalization thereby impacting patient safety and healthcare costs.

Strategies to optimize the clinical sensitivity and specificity of current laboratory tests are critical to differentiate the clinical CDI from colonization. To achieve high diagnostic yield, if preagreed institutional criteria for stool submission are not used, a multistep approach to CDI diagnosis is recommended, such as either GDH or NAAT followed by toxins A/B EIA in conjunction with laboratory stewardship by evaluating C. difficile test orders for appropriateness and providing feedback. Furthermore, antimicrobial stewardship, along with provider education on appropriate testing for C. difficile, is vital to differentiate CDI from colonization.

Advances and required improvements in methods to diagnosing Clostridioides difficile infections in the healthcare setting

INTRODUCTION

Clostrididioides difficile is associated with adverse clinical outcomes and increased morbidity, mortality, length of hospital stay, and health-care costs.Areas Covered: We searched relevant papers in PubMed for the last 10 years. In major papers, we scanned the bibliographies to ensure that important articles were included. This review addresses the evolving epidemiology of Clostridioides difficile infection (CDI) and discusses novel methods/approaches for improving the diagnosis of this important disease.

EXPERT OPINION

No single diagnostic test to date has demonstrated optimum sensitivity and specificity for detection of CDI. Many institutions have developed multi-step algorithms consistent with guidelines established by various professional societies. Some institutions have successfully tried to improve the pretest probability of molecular assays by implementing appropriate sample rejection criteria and establishing best practice alerts at the time of electronic order entry. Others have established PCR cycle threshold cutoffs to attempt to differentiate symptomatic patients from asymptomatic carriers or to make predictions about severity of disease with variable success. As research advances our understanding of C. difficile pathogenesis and pathophysiology, more information on CDI specific biomarkers is emerging. Finally, assessments of the microbiome and metabolome may expand the diagnostic armamentarium with advances in mass spectrometry and sequencing technologies.

Impact of a C. difficile infection (CDI) reduction bundle and its components on CDI diagnosis and prevention

BACKGROUND

Published bundles to reduce Clostridioides difficile Infection (CDI) frequently lack information on compliance with individual elements. We piloted a computerized clinical decision support-based intervention bundle and conducted detailed evaluation of several intervention-related measures.

METHODS

A quasi-experimental study of a bundled intervention was performed at 2 acute care community hospitals in Maryland. The bundle had five components: (1) timely placement in enteric precautions, (2) appropriate CDI testing, (3) reducing proton-pump inhibitor (PPI) use, (4) reducing high-CDI risk antibiotic use, and (5) optimizing use of a sporicidal agent for environmental cleaning. Chi-square and Kruskal-Wallis tests were used to compare measure differences. An interrupted time series analysis was used to evaluate impact on hospital-onset (HO)-CDI.

RESULTS

Placement of CDI suspects in enteric precautions before test results did not change. Only hospital B decreased the frequency of CDI testing and reduced inappropriate testing related to laxative use. Both hospitals reduced the use of PPI and high-risk antibiotics. A 75% decrease in HO-CDI immediately postimplementation was observed for hospital B only.

CONCLUSION

A CDI reduction bundle showed variable impact on relevant measures. Hospital-specific differential uptake of bundle elements may explain differences in effectiveness, and emphasizes the importance of measuring processes and intermediate outcomes.

Laboratory test ordering in inpatient hospitals: a systematic review on the effects and features of clinical decision support systems

Background

Studies have revealed inappropriate laboratory testing as a source of waste. This review aimed at evaluating the effects and features of CDSSs on physicians' appropriate laboratory test ordering in inpatient hospitals.

Method

Medline through PubMed, SCOPUS, Web of Science, and Cochrane were queried without any time period restriction. Studies using CDSSs as an intervention to improve laboratory test ordering as the primary aim were included. The study populations in the included studies were laboratory tests, physicians ordering laboratory tests, or the patients for whom laboratory tests were ordered. The included papers were evaluated for their outcomes related to the effect of CDSSs which were categorized based on the outcomes related to tests, physician, and patients. The primary outcome measures were the number and cost of the ordered laboratory tests. The instrument from The National Heart Lung and Blood Institute (NIH) was used to assess the quality of the included studies. Moreover, we applied a checklist for assessing the quality and features of the CDSSs presented in the included studies. A narrative synthesis was used to describe and compare the designs and the results of included studies.

Result

Sixteen studies met the inclusion criteria. Most studies were conducted based on a quasi-experimental design. The results showed improvement in laboratory test-related outcomes (e.g. proportion and cost of tests) and also physician-related outcomes (e.g. guideline adherence and orders cancellation). Patient-related outcomes (e.g. length of stay and mortality rate) were not well investigated in the included studies. In addition, the evidence about applying CDSS as a decision aid for interpreting laboratory results was rare.

Conclusion

CDSSs increase appropriate test ordering in hospitals through eliminating redundant test orders and enhancing evidence-based practice. Appropriate testing and cost saving were both affected by the CDSSs. However, the evidence is limited about the effects of laboratory test CDSSs on patient-related outcomes.

Improving Appropriate Diagnosis of Clostridioides difficile Infection Through an Enteric Pathogen Order Set With Computerized Clinical Decision Support: An Interrupted Time Series Analysis

Background

Inappropriate testing for Clostridioides difficile leads to overdiagnosis of C difficile infection (CDI). We determined the effect of a computerized clinical decision support (CCDS) order set on C difficile polymerase chain reaction (PCR) test utilization and clinical outcomes.

Methods

This study is an interrupted time series analysis comparing C difficile PCR test utilization, hospital-onset CDI (HO-CDI) rates, and clinical outcomes before and after implementation of a CCDS order set at 2 academic medical centers: University of Washington Medical Center (UWMC) and Harborview Medical Center (HMC).

Results

Compared with the 20-month preintervention period, during the 12-month postimplementation of the CCDS order set, there was an immediate and sustained reduction in C difficile PCR test utilization rates at both hospitals (HMC, -28.2% [95% confidence interval {CI}, -43.0% to -9.4%], P = .005; UWMC, -27.4%, [95% CI, -37.5% to -15.6%], P < .001). There was a significant reduction in rates of C difficile tests ordered in the setting of laxatives (HMC, -60.8% [95% CI, -74.3% to -40.1%], P < .001; UWMC, -37.3%, [95% CI, -58.2% to -5.9%], P = .02). The intervention was associated with an increase in the C difficile test positivity rate at HMC (P = .01). There were no significant differences in HO-CDI rates or in the proportion of patients with HO-CDI who developed severe CDI or CDI-associated complications including intensive care unit transfer, extended length of stay, 30-day mortality, and toxic megacolon.

Conclusions

Computerized clinical decision support tools can improve C difficile diagnostic test stewardship without causing harm. Additional studies are needed to identify key elements of CCDS tools to further optimize C difficile testing and assess their effect on adverse clinical outcomes.

Incorporating preauthorization into antimicrobial stewardship pharmacist workflow reduces Clostridioides difficile and gastrointestinal panel testing

OBJECTIVE

To evaluate whether incorporating mandatory prior authorization for Clostridioides difficile testing into antimicrobial stewardship pharmacist workflow could reduce testing in patients with alternative etiologies for diarrhea.

DESIGN

Single center, quasi-experimental before-and-after study.

SETTING

Tertiary-care, academic medical center in Ann Arbor, Michigan.

PATIENTS

Adult and pediatric patients admitted between September 11, 2019 and December 10, 2019 were included if they had an order placed for 1 of the following: (1) C. difficile enzyme immunoassay (EIA) in patients hospitalized >72 hours and received laxatives, oral contrast, or initiated tube feeds within the prior 48 hours, (2) repeat molecular multiplex gastrointestinal pathogen panel (GIPAN) testing, or (3) GIPAN testing in patients hospitalized >72 hours.

INTERVENTION

A best-practice alert prompting prior authorization by the antimicrobial stewardship program (ASP) for EIA or GIPAN testing was implemented. Approval required the provider to page the ASP pharmacist and discuss rationale for testing. The provider could not proceed with the order if ASP approval was not obtained.

RESULTS

An average of 2.5 requests per day were received over the 3-month intervention period. The weekly rate of EIA and GIPAN orders per 1,000 patient days decreased significantly from 6.05 ± 0.94 to 4.87 ± 0.78 (IRR, 0.72; 95% CI, 0.56-0.93; P = .010) and from 1.72 ± 0.37 to 0.89 ± 0.29 (IRR, 0.53; 95% CI, 0.37-0.77; P = .001), respectively.

CONCLUSIONS

We identified an efficient, effective C. difficile and GIPAN diagnostic stewardship approval model.

The Role of Diagnostic Stewardship in Clostridioides difficile Testing: Challenges and Opportunities

PURPOSE OF REVIEW

Accurate and timely diagnosis of Clostridioides difficile infection (CDI) is imperative to prevent C. difficile transmission and reduce morbidity and mortality due to CDI, but CDI laboratory diagnostics are complex. The purpose of this article is to review the role of laboratory tests in the diagnosis of CDI, and the role of diagnostic stewardship in optimization of C. difficile testing.

RECENT FINDINGS

Results from C. difficile diagnostic tests should be interpreted with an understanding of the strengths and limitations inherent in each testing approach. Use of highly sensitive molecular diagnostic tests without accounting for clinical signs and symptoms may lead to over-diagnosis of CDI and increased facility CDI rates. Current guidelines recommend a two-step, algorithmic approach for testing. Diagnostic stewardship interventions, such as education, order sets, order search menus, reflex orders, hard and soft stop alerts, electronic references, feedback and benchmarking, decision algorithms, and predictive analytics may help improve use of C. difficile laboratory tests and CDI diagnosis. The diagnostic stewardship approaches with the highest reported success rates include computerized clinical decision support (CCDS) interventions, face-to-face feedback, and real-time evaluations.

SUMMARY

CDI is a clinical diagnosis supported by laboratory findings. Together, clinical evaluation combined with diagnostic stewardship can optimize the accurate diagnosis of CDI.

Impact of an electronic hard-stop clinical decision support tool to limit repeat Clostridioides difficile toxin enzyme immunoassay testing on test utilization

We performed an intervention evaluating the impact of an electronic hard-stop clinical decision support tool on repeat Clostridioides difficile (CD) toxin enzyme immunoassay (T-EIA) testing. The CD testing rate and number of admissions with repeat tests decreased significantly postintervention (P < .01 for both); the percentage of positive tests was unchanged (P = .27).

A Laboratory Medicine Best Practices Systematic Review and Meta-analysis of Nucleic Acid Amplification Tests (NAATs) and Algorithms Including NAATs for the Diagnosis of Clostridioides (Clostridium) difficile in Adults

The evidence base for the optimal laboratory diagnosis of Clostridioides (Clostridium) difficile in adults is currently unresolved due to the uncertain performance characteristics and various combinations of tests. This systematic review evaluates the diagnostic accuracy of laboratory testing algorithms that include nucleic acid amplification tests (NAATs) to detect the presence of C. difficile The systematic review and meta-analysis included eligible studies (those that had PICO [population, intervention, comparison, outcome] elements) that assessed the diagnostic accuracy of NAAT alone or following glutamate dehydrogenase (GDH) enzyme immunoassays (EIAs) or GDH EIAs plus C. difficile toxin EIAs (toxin). The diagnostic yield of NAAT for repeat testing after an initial negative result was also assessed. Two hundred thirty-eight studies met inclusion criteria. Seventy-two of these studies had sufficient data for meta-analysis. The strength of evidence ranged from high to insufficient. The uses of NAAT only, GDH-positive EIA followed by NAAT, and GDH-positive/toxin-negative EIA followed by NAAT are all recommended as American Society for Microbiology (ASM) best practices for the detection of the C. difficile toxin gene or organism. Meta-analysis of published evidence supports the use of testing algorithms that use NAAT alone or in combination with GDH or GDH plus toxin EIA to detect the presence of C. difficile in adults. There is insufficient evidence to recommend against repeat testing of the sample using NAAT after an initial negative result due to a lack of evidence of harm (i.e., financial, length of stay, or delay of treatment) as specified by the Laboratory Medicine Best Practices (LMBP) systematic review method in making such an assessment. Findings from this systematic review provide clarity to diagnostic testing strategies and highlight gaps, such as low numbers of GDH/toxin/PCR studies, in existing evidence on diagnostic performance, which can be used to guide future clinical research studies.

Reduction in Clostridium difficile infection rates following a multifacility prevention initiative in Orange County, California: A controlled interrupted time series evaluation

OBJECTIVE

To evaluate the Orange County Clostridium difficile infection (CDI) prevention collaborative's effect on rates of CDI in acute-care hospitals (ACHs) in Orange County, California.

DESIGN

Controlled interrupted time series.

METHODS

We convened a CDI prevention collaborative with healthcare facilities in Orange County to reduce CDI incidence in the region. Collaborative participants received onsite infection control and antimicrobial stewardship assessments, interactive learning and discussion sessions, and an interfacility transfer communication improvement initiative during June 2015-June 2016. We used segmented regression to evaluate changes in monthly hospital-onset (HO) and community-onset (CO) CDI rates for ACHs. The baseline period comprised 17 months (January 2014-June 2015) and the follow-up period comprised 28 months (September 2015-December 2017). All 25 Orange County ACHs were included in the CO-CDI model to account for direct and indirect effects of the collaborative. For comparison, we assessed HO-CDI and CO-CDI rates among 27 ACHs in 3 San Francisco Bay Area counties.

RESULTS

HO-CDI rates in the 15 participating Orange County ACHs decreased 4% per month (incidence rate ratio [IRR], 0.96; 95% CI, 0.95-0.97; P &lt; .0001) during the follow-up period compared with the baseline period and 3% (IRR, 0.97; 95% CI, 0.95-0.99; P = .002) per month compared to the San Francisco Bay Area nonparticipant ACHs. Orange County CO-CDI rates declined 2% per month (IRR, 0.98; 95% CI, 0.96-1.00; P = .03) between the baseline and follow-up periods. This decline was not statistically different from the San Francisco Bay Area ACHs (IRR, 0.97; 95% CI, 0.95-1.00; P = .09).

CONCLUSIONS

Our analysis of ACHs in Orange County provides evidence that coordinated, regional multifacility initiatives can reduce CDI incidence.

Use of whole-genome sequencing to guide a Clostridioides difficile diagnostic stewardship program

Whole-genome sequencing (WGS) has yielded new insights into the transmission patterns of healthcare facility-onset Clostridioides difficile infection (HO-CDI). WGS results prompted a focused diagnostic stewardship program, which was associated with a significant and sustained decrease in HO-CDI at large, urban hospital.

Diagnostic stewardship of C. difficile testing: a quasi-experimental antimicrobial stewardship study

OBJECTIVE

We evaluated whether a diagnostic stewardship initiative consisting of ASP preauthorization paired with education could reduce false-positive hospital-onset (HO) Clostridioides difficile infection (CDI).

DESIGN

Single center, quasi-experimental study.

SETTING

Tertiary academic medical center in Chicago, Illinois.

PATIENTS

Adult inpatients were included in the intervention if they were admitted between October 1, 2016, and April 30, 2018, and were eligible for C. difficile preauthorization review. Patients admitted to the stem cell transplant (SCT) unit were not included in the intervention and were therefore considered a contemporaneous noninterventional control group.

INTERVENTION

The intervention consisted of requiring prescriber attestation that diarrhea has met CDI clinical criteria, ASP preauthorization, and verbal clinician feedback. Data were compared 33 months before and 19 months after implementation. Facility-wide HO-CDI incidence rates (IR) per 10,000 patient days (PD) and standardized infection ratios (SIR) were extracted from hospital infection prevention reports.

RESULTS

During the entire 52 month period, the mean facility-wide HO-CDI-IR was 7.8 per 10,000 PD and the SIR was 0.9 overall. The mean ± SD HO-CDI-IR (8.5 ± 2.0 vs 6.5 ± 2.3; P &lt; .001) and SIR (0.97 ± 0.23 vs 0.78 ± 0.26; P = .015) decreased from baseline during the intervention. Segmented regression models identified significant decreases in HO-CDI-IR (Pstep = .06; Ptrend = .008) and SIR (Pstep = .1; Ptrend = .017) trends concurrent with decreases in oral vancomycin (Pstep &lt; .001; Ptrend &lt; .001). HO-CDI-IR within a noninterventional control unit did not change (Pstep = .125; Ptrend = .115).

CONCLUSIONS

A multidisciplinary, multifaceted intervention leveraging clinician education and feedback reduced the HO-CDI-IR and the SIR in select populations. Institutions may consider interventions like ours to reduce false-positive C. difficile NAAT tests.

Clostridium difficile colonization among patients with clinically significant diarrhea and no identifiable cause of diarrhea

OBJECTIVE

To determine the prevalence of Clostridium difficile colonization among patients who meet the 2017 IDSA/SHEA C. difficile infection (CDI) Clinical Guideline Update criteria for the preferred patient population for C. difficile testing.

DESIGN

Retrospective cohort.

SETTING

Tertiary-care hospital in St. Louis, Missouri.PatientsPatients whose diarrheal stool samples were submitted to the hospital's clinical microbiology laboratory for C. difficile testing (toxin EIA) from August 2014 to September 2016.InterventionsElectronic and manual chart review were used to determine whether patients tested for C. difficile toxin had clinically significant diarrhea and/or any alternate cause for diarrhea. Toxigenic C. difficile culture was performed on all stool specimens from patients with clinically significant diarrhea and no known alternate cause for their diarrhea.

RESULTS

A total of 8,931 patients with stool specimens submitted were evaluated: 570 stool specimens were EIA positive (+) and 8,361 stool specimens were EIA negative (-). Among the EIA+stool specimens, 107 (19% of total) were deemed eligible for culture. Among the EIA- stool specimens, 515 (6%) were eligible for culture. One EIA+stool specimen (1%) was toxigenic culture negative. Among the EIA- stool specimens that underwent culture, toxigenic C. difficile was isolated from 63 (12%).

CONCLUSIONS

Most patients tested for C. difficile do not have clinically significant diarrhea and/or potential alternate causes for diarrhea. The prevalence of toxigenic C. difficile colonization among EIA- patients who met the IDSA/SHEA CDI guideline criteria for preferred patient population for C. difficile testing was 12%.

Diagnostic stewardship and the 2017 update of the IDSA-SHEA Clinical Practice Guidelines for Clostridium difficile Infection

Diagnostic stewardship is an increasingly recognized means to reduce unnecessary tests and diagnostic errors. As a leading cause of healthcare-associated infection for which accurate laboratory diagnosis remains a challenge, Clostridium difficile offers an ideal opportunity to apply the principles of diagnostic stewardship. The recently updated 2017 Infectious Diseases Society of America (IDSA)-Society for Healthcare Epidemiology of America (SHEA) Clinical Practice Guidelines for C. difficile infection now recommend separate diagnostic strategies depending on whether an institution has adopted diagnostic stewardship in test decision making. IDSA-SHEA endorsement of diagnostic stewardship for C. difficile highlights the increasing role of diagnostic stewardship in hospitals. In this opinion piece, we introduce the concept of diagnostic stewardship by discussing the new IDSA-SHEA diagnostic recommendations for laboratory diagnosis of C. difficile . We outline recent examples of diagnostic stewardship, challenges to implementation, potential downsides and propose future areas of study.