Why do clinicians order inappropriate Clostridium difficile testing? An exploratory study

Impact of mandatory nucleic acid amplification test (NAAT) testing approval on hospital-onset Clostridioides difficile infection (HO-CDI) rates: A diagnostic stewardship intervention

Misclassification of Clostridioides difficile colonization as hospital-onset C. difficile infection (HO-CDI) can lead to unnecessary treatment of patients and substantial financial penalties for hospitals. We successfully implemented mandatory C. difficile PCR testing approval as a strategy to optimize testing, which was associated with a significant decline in the monthly incidence of HO-CDI rates and lowering of our standardized infection ratio to 0.77 (from 1.03) 18 months after this intervention. Approval request served as an educational opportunity to promote mindful testing and accurate diagnosis of HO-CDI.

Does this patient have Clostridioides difficile infection? A systematic review and meta-analysis

BACKGROUND

The clinical features and predictors of Clostridioides difficile infection overlap with many conditions.

OBJECTIVES

We performed a systematic review to evaluate the diagnostic utility of clinical features (clinical examination, risk factors, laboratory tests, and radiographic findings) associated with C. difficile.

METHODS

Systematic review and meta-analysis of diagnostic features for C. difficile.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched up to September 2021.

STUDY ELIGIBILITY CRITERIA

Studies that reported clinical features of C. difficile, a valid reference standard test for confirming diagnosis of C. difficile, and a comparison among patients with a positive and negative test result.

PARTICIPANTS

Adult and paediatric patients across diverse clinical settings.

OUTCOMES

Sensitivity, specificity, likelihood ratios.

REFERENCE STANDARD

Stool nucleic acid amplification tests, enzyme immunoassays, cell cytotoxicity assay, and stool toxigenic culture.

ASSESSMENT OF RISK OF BIAS

Rational Clinical Examination Series and Quality Assessment of Diagnostic Accuracy Studies-2.

METHODS OF DATA SYNTHESIS

Univariate and bivariate analyses.

RESULTS

We screened 11 231 articles of which 40 were included, enabling the evaluation of 66 features for their diagnostic utility for C. difficile (10 clinical examination findings, 4 laboratory tests, 10 radiographic findings, prior exposure to 13 antibiotic types, and 29 clinical risk factors). Of the ten features identified on clinical examination, none were significantly clinically associated with increased likelihood of C. difficile infection. Some features that increased likelihood of C. difficile infection were stool leukocytes (LR+ 5.31, 95% CI 3.29-8.56) and hospital admission in the prior 3 months (LR+ 2.14, 95% CI 1.48-3.11). Several radiographic findings also strongly increased the likelihood of C. difficile infection like ascites (LR+ 2.91, 95% CI 1.89-4.49).

DISCUSSION

There is limited utility of bedside clinical examination alone in detecting C. difficile infection. Accurate diagnosis of C. difficile infection requires thoughtful clinical assessment for interpretation of microbiologic testing in all suspected cases.

Two-step algorithm-based Clostridioides difficile testing as a tool for antibiotic stewardship

OBJECTIVES

Diagnosis of Clostridium difficile infection (CDI) can be challenging due to high colonization rates. Unlike PCR-only testing, two-step algorithm testing (that includes toxin and PCR) may help differentiate colonization from active infection, but it is unknown if this type of testing impacts treatment decisions. We examined the association between changing CDI diagnostic methods, the way the testing results were displayed, and the rates of CDI-specific treatment.

METHODS

We performed a retrospective analysis of positive C. difficile cases over 2 years, a year preceding and following our institution's transition from PCR to two-step testing. During the PCR period, results were displayed in the electronic medical record as 'positive'. In the two-step period, positive results were either displayed as 'likely colonized' or 'toxin positive'. Rates of CDI-specific therapy and adverse patient outcomes (30-day mortality and intensive care unit admission) were compared among the three groups.

RESULTS

A total of 610 patients had positive results over the study period. Of the 354 patients in the PCR group, 329 (93%) were treated with CDI-specific therapy. Of the 142 patients in the likely colonized group, 59 (42%) were treated. All 114 patients in the toxin-positive group were treated. Multivariate analysis of patients who were PCR positive or likely colonized showed that tests sent in the two-step era were less likely to be associated with treatment for CDI (odds ratio 0.05, 95% CI 0.03-0.09).

DISCUSSION

We found a correlation between changing the type of test and the way the results were displayed and reduction in CDI-specific antibiotic use without restricting clinician diagnostic ordering.

Role of diagnostic stewardship in reducing healthcare-facility–onset Clostridioides difficile infections

We describe the implementation of an electronic medical record “hard stop” to decrease inappropriate Clostridioides difficile testing across a 5-hospital health system, effectively reducing the rates of healthcare-facility–onset C. difficile infection. This novel approach included expert consultation with medical director of infection prevention and control for test-order override.

Prevalence of and factors associated with inappropriate Clostridioides difficile testing in a teaching hospital in Korea

Background

Given the increasing incidence of Clostridioides difficile infections in Korea, there has been an increase in inappropriate testing for C. difficile, which has rendered overdiagnosis of asymptomatic colonisers common. We aimed to investigate the appropriateness of C. difficile testing and the related factors.

Methods

We retrospectively reviewed the medical records of patients who were admitted to a 1300-bed tertiary-care teaching hospital in Korea and were tested for C. difficile infection from September 2019 to November 2019. We performed logistic regression analysis to investigate factors related to inappropriate testing. Further, a survey was conducted on physicians to assess the knowledge and ordering patterns of C. difficile testing.

Results

We included 715 tests from 520 patients in the analysis. Testing was classified as hospital-onset and community-onset and subclassified as appropriate and inappropriate following an algorithmic method. Among the 715 tests, 576 (80.6%) and 139 (19.6%) tests were classified as hospital-onset and community-onset, respectively. Among the hospital-onset tests, 297 (52%) were considered inappropriate. The risk of inappropriate testing increased when C. difficile tests were conducted in the emergency room (OR 24.96; 95% CI 3.12–199.98) but decreased in intensive care units (OR 0.36, 95% CI 0.19–0.67). The survey was conducted on 61 physicians. Internal medicine physicians had significantly higher scores than non-internal medicine physicians (7.1 vs. 5.7, p = 0.001). The most frequently ordered combination of tests was toxin + glutamate dehydrogenase (47.5%), which was consistent with the ordered tests.

Conclusion

Almost half of the C. difficile tests were performed inappropriately. The patient being located in the emergency room and intensive care unit increased and decreased the risk of inappropriate testing, respectively. In a questionnaire survey, we showed that internal medicine physicians were more knowledgeable about C. difficile testing than non-internal medicine physicians. There is a need to implement the diagnostic stewardship for C. difficile, especially through educational interventions for emergency room and non-internal medicine physicians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01111-0.

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.

Reduction in Health Care Facility-Onset Clostridioides difficile Infection: A Quality Improvement Initiative

Objective

To reduce health care facility–onset (HCFO) Clostridioides difficile infection (CDI) incidence by improving diagnostic stewardship and reducing the inappropriate testing of C difficile assays.

Patients and Methods

A multidisciplinary team conducted a quality improvement initiative from January 1, 2020, through March 31, 2021. Clostridioides difficile infection and inappropriate testing were identified via electronic health records using predefined criteria related to stool quantity/caliber, confounding medications, and laboratory data. An intervention bundle was designed including (1) provider education, (2) implementation of an appropriate testing algorithm, (3) expert review of C difficile orders, and (4) batch testing of assays to facilitate review and cancellation if inappropriate.

Results

Compared with a baseline period from January to September 2020, implementation of our intervention bundle from December 2020 to March 2021 resulted in an 83.6% reduction in inappropriate orders tested and a 41.7% reduction in HCFO CDI incidence.

Conclusion

A novel prevention bundle improved C difficile diagnostic stewardship and HCFO CDI incidence by reducing testing of inappropriate orders. Such initiatives targeting HCFO CDI may positively affect patient safety and hospital reimbursement.

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.

Utilizing a real-time discussion approach to improve the appropriateness of Clostridioides difficile testing and the potential unintended consequences of this strategy

We report electronic medical record interventions to reduce Clostridioides difficile testing risk 'alert fatigue.' We used a behavioral approach to diagnostic stewardship and observed a decrease in the number of tests ordered of ~4.5 per month (P < .0001). Although the number of inappropriate tests decreased during the study period, delayed testing increased.