Safety and cost savings of an improved three-day rule for stool culture in hospitalised children and adults

A diagnostic stewardship approach to prevent unnecessary testing of an enteric bacterial molecular panel

IMPORTANCE

Testing for enteric bacterial pathogens in patients hospitalized for more than 3 days is almost always inappropriate. Our study validates the utility of the 3-day rule and the use of clinical decision support tools to decrease unnecessary testing of enteropathogenic bacteria other than C. difficile. Overriding the restriction was very low yield. Our study highlights the importance of diagnostic stewardship and further refines the criteria for allowing providers to override the restriction while monitoring the impact of the interventions.

The 3-day rule for stool cultures: should all patients with haematological malignancies be excluded?

OBJECTIVES

The '3-day rule' for stool culture ordering suggests that only selected inpatients with nosocomial diarrhoea should have stool cultures for enteropathogenic bacteria (EPBs). Patients with haematological malignancies are not included in this group. We have analysed the ordering of stool cultures at Laikon Hospital to investigate whether all patients with haematological malignancies should be excluded from the 3-day rule.

METHODS

We have retrospectively analysed all inpatient stool specimens sent to the microbiology laboratory for enteropathogenic bacteria culture at Laikon Hospital, Athens, Greece, between January 1, 2014 and December 31, 2014. We classified stool cultures sent after the third day as 'appropriate', 'excluded' with standard rule, 'excluded' with haematological malignancies, and 'inappropriate'.

RESULTS

During the study period, 1101/1593 inpatient stool cultures (69.1%) had been ordered after the third day of hospitalization. The total yield for inpatient EPB stool cultures was 0.7% (11/1593). The yield for 'appropriate' cultures was significantly higher than the yield of all 'excluded' specimens (3.7% (3/81) versus 0.3% (2/585), p 0.018) and to 'inappropriate' orders (3.7% (3/81) versus 0.0% (0/485), p 0.0028). There was no difference in the yield between specimens 'excluded' with the standard rule and 'excluded' with haematological malignancies.

CONCLUSIONS

In our hospital, the yield of stool cultures from patients with haematological malignancies is similar to that of patients 'excluded' from the standard 3-day rule. If patients with haematological malignancies were not excluded from the rule, we would reduce the inpatient stool cultures by 13.6% (217/1593) at the cost of missing one positive stool culture.

Reducing Inappropriate Testing for the Evaluation of Diarrhea Among Hospitalized Patients

BACKGROUND

Diarrhea is one of the most common illnesses in the United States. Evaluation frequently does not follow established guidelines. The objective of this study was to evaluate the effectiveness of a computerized physician order entry-based test guidance algorithm with regard to the clinical, financial, and operational impacts.

METHODS

Our population was patients with diarrheal illness at a tertiary academic medical center. The intervention was a computerized physician order entry-based test guidance algorithm that restricted the use of stool cultures and ova and parasites testing of diarrhea in the adult inpatient location vs nonintervention sites, which were the emergency department, pediatric inpatient and adult and pediatric outpatient locations. We measured stool culture, ova and parasites, and Clostridium difficile testing rates from July 1, 2012 to January 31, 2016. Additionally, we calculated advisor usage, consults generated, accuracy of information, and cost savings.

RESULTS

There was a significant decrease in stool culture and ova and parasites testing rates at the adult inpatient (P = .001 for both), pediatric (P < .001 for both), and adult emergency department (P < .001; P = .009) locations. The decrease at the intervention site was immediate, whereas the other locations showed a delayed but sustained decrease that suggests a collateral impact. A significant increase in the rate of stool culture and ova and parasites testing was observed in the outpatient setting (P = .02 and P = .001). We estimate that $21,931 was saved annually.

CONCLUSIONS

A point-of-order test restriction algorithm for hospitalized adults with diarrhea reduced stool testing. Similar programs should be considered at other institutions and for the evaluation of other conditions.

The yield of stool testing in hospital-onset diarrhea: Has evidence changed practice?

INTRODUCTION

Aside from examination for Clostridium difficile, the yield of stool testing in hospital-onset diarrhea is poor. Clinical practice guidelines discourage overzealous stool testing in patients with diarrhea that develops after the third hospital day. However, the adoption of this recommendation into clinical practice is limited. Furthermore, the effect of microbiology laboratory improvements on hospital-onset diarrhea testing is largely unknown.

METHODS

A retrospective cohort study was conducted in a university-affiliated community-hospital and included all adult inpatients who developed diarrhea after hospitalization.

RESULTS

132 adult patients (53% female) developed diarrhea after hospitalization in 2013. The cohort's mean age was 55.6 years. 46.2% of patients developed diarrhea in the first 3 days of hospitalization. Testing for parasites was negative in all examined 67 samples. Testing for C. difficile was positive in 13 cases (10.8%) out of 120 tested samples. Testing for other pathogens was positive in 1 sample (Campylobacter) out of 129 samples. Stool samples tested in the first 3 days of hospitalization were more likely to be positive (64.3 vs 35.7%, p = 0.1). Change in management was reported in 9 out of 14 patients (64.3%) with positive stool testing compared with 31 out of 118 patients (26.3%) with negative stool testing, p = 0.01.

CONCLUSION

Despite improvements in stool samples' testing, the yield continues to be low, especially in hospital-onset diarrhea past the third hospital day. Physicians' embracement of the '3-day rule' continues to be poor.

Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Bacterial Gastroenteritis

Bacterial gastroenteritis is a disease that is pervasive in both the developing and developed worlds. While for the most part bacterial gastroenteritis is self-limiting, identification of an etiological agent by bacterial stool culture is required for the management of patients with severe or prolonged diarrhea, symptoms consistent with invasive disease, or a history that may predict a complicated course of disease. Importantly, characterization of bacterial enteropathogens from stool cultures in clinical laboratories is one of the primary means by which public health officials identify and track outbreaks of bacterial gastroenteritis. This article provides guidance for clinical microbiology laboratories that perform stool cultures. The general characteristics, epidemiology, and clinical manifestations of key bacterial enteropathogens are summarized. Information regarding optimal specimen collection, transport, and processing and current diagnostic tests and testing algorithms is provided. This article is an update of Cumitech 12A (P. H. Gilligan, J. M. Janda, M. A. Karmali, and J. M. Miller, Cumitech 12A, Laboratory diagnosis of bacterial diarrhea, 1992).

A parallel diagnostic accuracy study of three molecular panels for the detection of bacterial gastroenteritis

Culture-dependent detection of gastroenteric bacteria is labour-intensive and does not provide results in a clinically relevant time frame. Several commercially available multiplex molecular panels are now available which may be more sensitive and could potentially provide rapid results. We compared the diagnostic accuracy, turnaround time and ease of use of three such molecular panels: the RIDA®GENE Bacterial Stool and EHEC/EPEC Panels (R-Biopharm AG, Darmstadt, Germany), the FTD® Bacterial Gastroenteritis Panel (Fast Track Diagnostics, Junglinster, Luxembourg) and the BD MAX™ Enteric Bacterial Panel (Becton Dickinson GmbH, Heidelberg, Germany). The results from 116 retrospective selected and 318 prospective unselected stool samples were compared with conventional culture-based techniques using a gold standard for a positive test of either culture or agreement in two of the three molecular panels. For most targets, the molecular panels were more sensitive than culture, detecting an additional 13 cases that culture missed. The laboratory turnaround time was under 3 h for all molecular panels, compared with 66.5 h for culture. The BD MAX™ panel was the fastest, easiest to use and most flexible.

Validation of the 3-day rule for stool bacterial tests in Japan

OBJECTIVE

Stool cultures are expensive and time consuming, and the positive rate of enteric pathogens in cases of nosocomial diarrhea is low. The 3-day rule, whereby clinicians order a Clostridium difficile (CD) toxin test rather than a stool culture for inpatients developing diarrhea >3 days after admission, has been well studied in Western countries. The present study sought to validate the 3-day rule in an acute care hospital setting in Japan.

METHODS

Stool bacterial and CD toxin test results for adult patients hospitalized in an acute care hospital in 2008 were retrospectively analyzed. Specimens collected after an initial positive test were excluded. The positive rate and cost-effectiveness of the tests were compared among three patient groups.

PATIENTS

The adult patients were divided into three groups for comparison: outpatients, patients hospitalized for ≤3 days and patients hospitalized for ≥4 days.

RESULTS

Over the 12-month period, 1,597 stool cultures were obtained from 992 patients, and 880 CD toxin tests were performed in 529 patients. In the outpatient, inpatient ≤3 days and inpatient ≥4 days groups, the rate of positive stool cultures was 14.2%, 3.6% and 1.3% and that of positive CD toxin tests was 1.9%, 7.1% and 8.5%, respectively. The medical costs required to obtain one positive result were 9,181, 36,075 and 103,600 JPY and 43,200, 11,333 and 9,410 JPY, respectively.

CONCLUSION

The 3-day rule was validated for the first time in a setting other than a Western country. Our results revealed that the "3-day rule" is also useful and cost-effective in Japan.

Performance of stool cultures before and after a 3-day hospitalization: fewer cultures, better for patients and for money

We evaluated retrospectively the yield of stool culture (SC) depending on the length of hospitalization, and we characterized the patients missed by the 3-day rejection rule. SC detects bacterial enteric pathogens (Campylobacter spp., Salmonella enterica, Yersinia spp., Shigella spp.). During this 5-year study period, 13,039 SCs were requested, and 376 were positive (2.9%). The yield of SC dropped from 11.7% before 3 days of hospitalization to 0.7% after 3 days in children and 4.3% to 0.3% in adults. Finally, only 13 clinically relevant cases (0.2% of SC prescribed after 3 days) were undiagnosed by strict application of the 3-day rule. In conclusion, rejection of SC prescribed after 3 days of hospitalization allows to reduce workload by 37.8% for children and 65.7% for adults, representing a cost of €12,500 ($16,250) per year in our hospital.

Recognition and prevention of hospital-associated enteric infections in the intensive care unit

The objectives of this article were to review the causes and extent of hospital-associated infectious diarrhea and associated risks in the general hospital ward and intensive care unit (ICU), to compare microorganisms with similar symptoms to aid in recognition that will lead to timely and appropriate treatment and control measures, and to propose infection prevention protocols that could decrease human process errors in the ICU. This literature review describes epidemiology, comparison of microbial characteristics for potential hospital-associated enteric pathogens, diagnosis, and prevention, especially if important in the ICU, and particularly in regard to Clostridium difficile. Enteric organisms that most commonly cause hospital-associated infectious diarrhea in acute care settings and the ICU are C. difficile, rotavirus, and norovirus, although others may also be important, particularly in developing countries. To recognize and control infectious diarrhea successfully in the ICU, intensivists should be aware that epidemiology, risks, and prevention measures may differ between these microorganisms. In addition, intensivists should be ready to implement systems changes related to notification, isolation precautions and prevention, and environmental cleaning in the ICU.