Model to evaluate the impact of hospital-based interventions targeting false-positive blood cultures on economic and clinical outcomes

Do blood contamination reduction devices work? A single institution comparison

We compare two initial specimen diversion devices evaluated over 3 months to investigate their utility in lowering blood culture contamination rates at or below 1%. Overall contamination rates during trial periods were 2.46% and 2.60% but usage was low, whereas device-specific contamination rates were 0.68% and 0.8%, respectively.

Evaluation of hospital-onset bacteraemia and fungaemia in the USA as a potential healthcare quality measure: a cross-sectional study

BACKGROUND

Hospital-onset bacteraemia and fungaemia (HOB) is being explored as a surveillance and quality metric. The objectives of the current study were to determine sources and preventability of HOB in hospitalised patients in the USA and to identify factors associated with perceived preventability.

METHODS

We conducted a cross-sectional study of HOB events at 10 academic and three community hospitals using structured chart review. HOB was defined as a blood culture on or after hospital day 4 with growth of one or more bacterial or fungal organisms. HOB events were stratified by commensal and non-commensal organisms. Medical resident physicians, infectious disease fellows or infection preventionists reviewed charts to determine HOB source, and infectious disease physicians with training in infection prevention/hospital epidemiology rated preventability from 1 to 6 (1=definitely preventable to 6=definitely not preventable) using a structured guide. Ratings of 1-3 were collectively considered 'potentially preventable' and 4-6 'potentially not preventable'.

RESULTS

Among 1789 HOB events with non-commensal organisms, gastrointestinal (including neutropenic translocation) (35%) and endovascular (32%) were the most common sources. Overall, 636/1789 (36%) non-commensal and 238/320 (74%) commensal HOB events were rated potentially preventable. In logistic regression analysis among non-commensal HOB events, events attributed to intravascular catheter-related infection, indwelling urinary catheter-related infection and surgical site infection had higher odds of being rated preventable while events with neutropenia, immunosuppression, gastrointestinal sources, polymicrobial cultures and previous positive blood culture in the same admission had lower odds of being rated preventable, compared with events without those attributes. Of 636 potentially preventable non-commensal HOB events, 47% were endovascular in origin, followed by gastrointestinal, respiratory and urinary sources; approximately 40% of those events would not be captured through existing healthcare-associated infection surveillance.

DISCUSSION

Factors identified as associated with higher or lower preventability should be used to guide inclusion, exclusion and risk adjustment for an HOB-related quality metric.

Clinical Nurse Specialist Role Advocacy: Quantifying the Financial Contributions Via Development of a Scorecard

PURPOSE/OBJECTIVES

The purpose of this article is to guide the clinical nurse specialist in constructing a scorecard to track clinical outcomes and identify the associated financial impact.

DESCRIPTION OF THE PROJECT/PROGRAM

Creation of a scorecard highlighting the financial impact of the clinical nurse specialist team was used to disseminate financial outcomes to hospital executive stakeholders, allowing the clinical nurse specialist team to demonstrate its clinical and financial value.

OUTCOME

During development and ongoing maintenance of the scorecard, the clinical nurse specialist team cultivated skills to identify the financial impact of projects. The team also utilized financial implications of individual and group projects to prioritize work. At the end of fiscal year 2022, the clinical nurse specialist team demonstrated revenue generation of $29 890 and cost avoidance of $2 854 807.30. The clinical nurse specialist scorecard was presented quarterly to the chief nursing officer, who shared with executive leadership.

CONCLUSION

Clinical nurse specialists are positioned to make significant and positive financial impact to organizations. A scorecard presented to executive leadership offers a clinical nurse specialist team a tool to capture and disseminate a clinical nurse specialist team's unique financial contribution at the system level.

Determination of Ideal Factors for Early Adoption and Standardization of Metagenomic Next-generation Sequencing for Respiratory System Infections

BACKGROUND

Metagenomic next-generation sequencing (mNGS) demonstrates great promise as a diagnostic tool for determining the cause of pathogenic infections. The standard diagnostic procedures (SDP) include smears and cultures and are typically viewed as less sensitive and more time-consuming when compared to mNGS. There are concerns about the logistics and ease of transition from SDP to mNGS. mNGS lacks standardization of collection processes, databases, and sequencing. Additionally, there is the burden of training clinicians on interpreting mNGS results.

OBJECTIVE

Until now, few studies have explored factors that could be used as early adoption candidates to ease the transition between SDP and mNGS. This study evaluated 123 patients who had received both SDP and mNGS and compared several variables across a diagnostic test evaluation.

METHODS

The diagnostic test evaluation observed metrics such as sensitivity, specificity, positive and negative likelihood ratios (PLR, NLR), positive and negative predictive values (PPV, NPV), and accuracy. Factors included various sample sources such as bronchoalveolar lavage fluid (BALF), lung tissue, and cerebral spinal fluid (CSF). An additional factor observed was the patient's immune status.

RESULTS

Pathogen detection was found to be significantly greater for mNGS for total patients, BALF sample source, CSF sample source, and non-immunocompromised patients (p<0.05). Pathogen detection was found to be insignificant for lung tissue sample sources and immunocompromised patients. Sensitivity, PLR, NLR, PPV, NPV, and accuracy appeared to be higher with mNGS for the total patients, BALF sample source, and non-immunocompromised patients when compared with SDP (p<0.05).

CONCLUSION

With higher metrics in sensitivity, specificity, PLR, NLR, PPV, NPV, and accuracy for overall patients, mNGS may prove a better diagnostic tool than SDP. When addressing sample sources, mNGS for BALF-collected samples appeared to have higher scores than SDP for the same metrics. When patients were in a non-immunocompromised state, mNGS also demonstrated greater diagnostic benefits to BALF and overall patients compared to SDP. This study demonstrates that using BALF as a sample source and selecting non-immunocompromised patients may prove beneficial as early adoption factors for mNGS standard protocol. Such a study may pave the road for mNGS as a routine clinical method for determining the exact pathogenic etiology of lung infections.

Diagnostic Stewardship: A Systematic Review and Meta-analysis of Blood Collection Diversion Devices Used to Reduce Blood Culture Contamination and Improve the Accuracy of Diagnosis in Clinical Settings

Background

Blood culture contamination may lead to misdiagnosis, overutilization of antibiotics, and prolonged length of stay. Blood specimen diversion devices can reduce contamination rates during blood culture collection procedures. We performed a systematic literature review and meta-analysis evaluating the influence of blood specimen diversion devices in blood culture contamination rates.

Methods

We searched Medline, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science, from database inception to 1 March 2023, for studies evaluating the impact of a diversion device on blood culture contamination. Blood culture contamination was a positive blood culture with microorganisms not representative of true bacteremia, but rather introduced during collection or processing the blood sample. Random-effects models were used to obtain pooled mean differences, and heterogeneity was assessed using the I2 test.

Results

Of 1768 screened studies, 12 met inclusion criteria for this systematic literature review. Of them, 9 studies were included in the meta-analysis. Studies were substantially heterogeneous, but stratified analyses considering only high-quality studies revealed that venipuncture using a diversion device was associated with a significant reduction in blood culture contamination in comparison to the standard procedure of collection (pooled odds ratio [OR], 0.26 [95% confidence interval {CI}, .13-.54]; I2 = 19%). Furthermore, the stratified analysis showed that the adoption of a diversion device did not reduce the detection of true infection (pooled OR, 0.85 [95% CI, .65-1.11]; I2 = 0%).

Conclusions

Blood culture diversion devices was associated with decreased contamination rates and could improve quality of care, reduce costs, and avoid unnecessary antibiotic use.

The Impact of Initial Specimen Diversion Systems on Blood Culture Contamination

Blood culture contamination is associated with increased antimicrobial use, length of stay, and hospital cost. To address this problem, blood culture diversion has been developed as an additional measure to reduce contamination to targeted goals. Three different versions were proposed, including an open technique and 2 commercially available devices. This study aims to review the existing literature and analyze evidence for these 3 techniques.

Verification of quality assurance for blood culture surveillance using 6 years of data from the Japan Infection Prevention and Control Conference for National and Public University Hospitals

The importance of blood culture has been widely recognized, and there is a need for monitoring to evaluate the accuracy of blood culture that reflects domestic healthcare systems. In this study, we assessed 6-year trends in blood culture quality assurance data. The Japan Infection Prevention and Control Conference for National and Public University Hospitals conducted yearly blood culture surveillance at 52 national public university hospitals from 2015 to 2020. Statistical analysis showed that comparison with the previous year showed significant differences in the number of blood cultures per 1000 patient-days in all years. The number of blood cultures per 1000 admissions was not significantly different in 2017 and 2018, but significant differences were shown in all other years. The multiple blood culture set rate was significantly different between non-pediatric inpatients and outpatients but not between pediatric inpatients and outpatients. The contamination rate did not differ significantly. For all parameters, significant differences were found when comparing 2015 and 2020. Our survey showed that although the sample number improved over time, even the most recent values for 2020 were lower than Cumitech's targets. It is difficult to assess whether these sample numbers are appropriate because target values have not been set for the various types of hospitals in Japan. Surveillance is a useful tool for monitoring quality assurance for blood culture. All parameters improved over the 6-year period, but it is necessary to establish a benchmark for evaluating optimization. We will continue to monitor quality assurance and work on setting benchmarks.

Hospital-onset bacteremia and fungemia: An evaluation of predictors and feasibility of benchmarking comparing two risk-adjusted models among 267 hospitals

Objectives:

To evaluate the prevalence of hospital-onset bacteremia and fungemia (HOB), identify hospital-level predictors, and to evaluate the feasibility of an HOB metric.

Methods:

We analyzed 9,202,650 admissions from 267 hospitals during 2015–2020. An HOB event was defined as the first positive blood-culture pathogen on day 3 of admission or later. We used the generalized linear model method via negative binomial regression to identify variables and risk markers for HOB. Standardized infection ratios (SIRs) were calculated based on 2 risk-adjusted models: a simple model using descriptive variables and a complex model using descriptive variables plus additional measures of blood-culture testing practices. Performance of each model was compared against the unadjusted rate of HOB.

Results:

Overall median rate of HOB per 100 admissions was 0.124 (interquartile range, 0.00–0.22). Facility-level predictors included bed size, sex, ICU admissions, community-onset (CO) blood culture testing intensity, and hospital-onset (HO) testing intensity, and prevalence (all P < .001). In the complex model, CO bacteremia prevalence, HO testing intensity, and HO testing prevalence were the predictors most associated with HOB. The complex model demonstrated better model performance; 55% of hospitals that ranked in the highest quartile based on their raw rate shifted to a lower quartile when the SIR from the complex model was applied.

Conclusions:

Hospital descriptors, aggregate patient characteristics, community bacteremia and/or fungemia burden, and clinical blood-culture testing practices influence rates of HOB. Benchmarking an HOB metric is feasible and should endeavor to include both facility and clinical variables.

Initial Specimen Diversion Device Utilization Mitigates Blood Culture Contamination Across Regional Community Hospital and Acute Care Facility

A West Virginia regional community hospital incorporated an initial specimen diversion device (ISDD) into conventional blood culture protocol with the objective to bring the hospital-wide blood culture contamination (BCC) rate from a 3.06% preintervention rate to a target performance level below 1%. Emergency department staff, laboratory phlebotomists, and nursing staff on acute-critical care floors were trained on ISDD (Steripath Gen2, Magnolia Medical Technologies, Inc., Seattle, WA) operating procedure and utilized the device for blood culture sample collection with adult patients from September 2020 through April 2021. Of 5642 blood culture sets collected hospital-wide, 4631 were collected with the ISDD, whereas the remaining sets were collected via the conventional method. The ISDD BCC rate of 0.78% differed from the conventional method BCC rate of 4.06% observed during the intervention period (chi-squared test P < 0.00001). The ISDD group attained a sub-1% BCC rate to satisfy the intervention objective.

Diagnostic Testing for Sepsis: A Systematic Review of Economic Evaluations

Introduction: Sepsis is a serious and expensive healthcare problem, when caused by a multidrug-resistant (MDR) bacteria mortality and costs increase. A reduction in the time until the start of treatment improves clinical results. The objective is to perform a systematic review of economic evaluations to analyze the cost-effectiveness of diagnostic methods in sepsis and to draw lessons on the methods used to incorporate antimicrobial resistance (AMR) in these studies. Material and Methods: the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the Consolidated Health Economic Evaluation Reporting standards (CHEERS) checklist was used to extract the information from the texts. Results: A total of 16 articles were found. A decision model was performed in 14. We found two ways to handle resistance while modelling: the test could identify infections caused by a resistant pathogen or resistance-related inputs, or outcomes were included (the incidence of AMR in sepsis patients, antibiotic use, and infection caused by resistant bacterial pathogens). Conclusion: Using a diagnostic technique to detect sepsis early on is more cost-effective than standard care. Setting a direct relationship between the implementation of a testing strategy and the reduction of AMR cases, we made several assumptions about the efficacy of antibiotics and the length-of-stay of patients.

Evaluation of an Initial Specimen Diversion Device (ISDD) on Rates of Blood Culture Contamination in the Emergency Department

Introduction

Blood cultures are the gold standard for identifying bloodstream infections. The Clinical and Laboratory Standards Institute recommends a blood culture contamination rate of less than 3%. Contamination can lead to misdiagnosis, increased length of stay and hospital costs, unnecessary testing, and antibiotic use. These reasons led to the development of initial specimen diversion devices (ISDD). The purpose of this study was to evaluate the impact of an initial specimen diversion device on rates of blood culture contamination in the emergency department.

Methods

This was a retrospective, multi-site study including patients who had blood cultures drawn in an emergency department. February 2018 to April 2018, when an ISDD was not utilized, was compared with June 2019 to August 2019, when an ISDD was being used. The primary outcome was total blood culture contamination. Secondary outcomes were total hospital cost, hospital and intensive care unit length of stay, vancomycin duration of use, vancomycin serum concentrations obtained, and repeat blood cultures obtained.

Results

A statistically significant difference was found in blood culture contamination rates in the pre-ISDD group vs. the ISDD group (7.47% vs. 2.59%, p < 0.001). None of the secondary endpoints showed a statistically significant difference.

Conclusions

Implementation of an ISDD reduced blood culture contamination. When implementing the ISDD to a healthcare system, compliance is important and will affect contamination rates dramatically.

Prevalence and Predictors of Bacterial Contamination in Excisional Lymph Node Biopsies: Implications for Diagnosis and Management

Routine tissue handling exposes lymph node specimens to microbial contamination that can confound microbiological culture results and interfere with diagnosis. The scope and impact of this problem remain poorly understood. We combined over 13 years of lymph node pathology, culture data, and patient records to define the prevalence, predisposing factors, microbiology, and clinical management of false-positive lymph node cultures at a large academic medical center. Nearly one third (31.9%) of 216 cultured lymph nodes yielded bacterial growth. Approximately 90% of positive bacterial cultures grew 1 of 2 common skin-resident taxa-coagulase-negative Staphylococcus and Cutibacterium acnes-with well-documented predispositions for contamination in other clinical settings. Lymph nodes excised from axillary, cervical, and inguinal regions yielded higher positive culture rates than nodes excised from the mediastinum, suggesting proximity to the skin surface may increase contamination risk. Accordingly, cultures from thoracoscopic pulmonary resections displayed contamination rates over 5-fold lower than those from percutaneously accessed lymph nodes. Lymph nodal tissue allocated for culture in the operating room yielded unexpectedly high contamination rates, significantly higher than cultures sent from the frozen section processing area. A significant minority of contamination events were noted in the clinical record and prompted antibiotic therapy on multiple occasions. Collectively, our results illuminate the risk factors contributing to bacterial contamination and argue that routine lymph node bacterial cultures provide minimal clinical benefit for adult patients. This widespread bacterial contamination also warrants cautious implementation of increasingly sensitive molecular microbiology tools for excised tissues.

Clinical consequences of contaminated blood cultures in adult hospitalized patients at an institution utilizing a rapid blood-culture identification system

OBJECTIVE

To assess the clinical impact of contaminated blood cultures in hospitalized patients during a period when rapid diagnostic testing using a FilmArray Blood Culture Identification (BCID) panel was in use.

DESIGN

Retrospective cohort study.

SETTING

Single academic medical center.

PARTICIPANTS

Patients who had blood culture(s) performed during an admission between June 2014 and December 2016.

METHODS

Length of hospital stay and days of antibiotic therapy were assessed in relation to blood-culture contamination using generalized linear models with univariable and multivariable analyses.

RESULTS

Among 11,474 patients who had blood cultures performed, the adjusted mean length of hospital stay for patients with contaminated blood-culture episodes (N = 464) was 12.3 days (95% confidence interval [CI], 11.4-13.2) compared to 11.5 days (95% CI, 11.0-11.9) for patients (N = 11,010) with negative blood-culture episodes (P = .032). The adjusted mean durations of antibiotic therapy for patients with contaminated and negative blood-culture episodes were 6.0 days (95% CI, 5.3-6.7) and 5.2 days (95% CI, 4.9-5.4), respectively (P = .011).

CONCLUSIONS

Despite the use of molecular-based, rapid blood-culture identification, contamination of blood cultures continues to result in prolonged hospital stay and unnecessary antibiotic therapy in hospitalized patients.

Modern Blood Culture: Management Decisions and Method Options

The optimal care of septic patients depends on the successful recovery of clinically relevant microorganisms from blood cultures and the timely reporting of organism identification and antimicrobial susceptibility testing (AST) results. Many preanalytic factors play a critical role in culturing microorganisms, and advancements in blood culture instrument technology have reduced the time to positive results. Additionally, rapid organism identification and AST results directly from positive blood culture broth via new methods help to further shorten the time from empiric to targeted treatment. This article summarizes the current state of blood culture methods, including preanalytic, analytical, and postanalytic factors that are available to clinical microbiology laboratories.

Practical Guidance for Clinical Microbiology Laboratories: A Comprehensive Update on the Problem of Blood Culture Contamination and a Discussion of Methods for Addressing the Problem

In this review, we present a comprehensive discussion of matters related to the problem of blood culture contamination. Issues addressed include the scope and magnitude of the problem, the bacteria most often recognized as contaminants, the impact of blood culture contamination on clinical microbiology laboratory function, the economic and clinical ramifications of contamination, and, perhaps most importantly, a systematic discussion of solutions to the problem. We conclude by providing a series of unanswered questions that pertain to this important issue.