Trends in catheter-associated urinary tract infections among a national cohort of hospitalized adults, 2001-2010

Automating detection of diagnostic error of infectious diseases using machine learning

Diagnostic error, a cause of substantial morbidity and mortality, is largely discovered and evaluated through self-report and manual review, which is costly and not suitable to real-time intervention. Opportunities exist to leverage electronic health record data for automated detection of potential misdiagnosis, executed at scale and generalized across diseases. We propose a novel automated approach to identifying diagnostic divergence considering both diagnosis and risk of mortality. Our objective was to identify cases of emergency department infectious disease misdiagnoses by measuring the deviation between predicted diagnosis and documented diagnosis, weighted by mortality. Two machine learning models were trained for prediction of infectious disease and mortality using the first 24h of data. Charts were manually reviewed by clinicians to determine whether there could have been a more correct or timely diagnosis. The proposed approach was validated against manual reviews and compared using the Spearman rank correlation. We analyzed 6.5 million ED visits and over 700 million associated clinical features from over one hundred emergency departments. The testing set performances of the infectious disease (Macro F1 = 86.7, AUROC 90.6 to 94.7) and mortality model (Macro F1 = 97.6, AUROC 89.1 to 89.1) were in expected ranges. Human reviews and the proposed automated metric demonstrated positive correlations ranging from 0.231 to 0.358. The proposed approach for diagnostic deviation shows promise as a potential tool for clinicians to find diagnostic errors. Given the vast number of clinical features used in this analysis, further improvements likely need to either take greater account of data structure (what occurs before when) or involve natural language processing. Further work is needed to explain the potential reasons for divergence and to refine and validate the approach for implementation in real-world settings.

An international prospective study of INICC analyzing the incidence and risk factors for catheter-associated urinary tract infections in 235 ICUs across 8 Asian Countries

BACKGROUND

Identify urinary catheter (UC)-associated urinary tract infections (CAUTI) incidence and risk factors (RF) in 235 ICUs in 8 Asian countries: India, Malaysia, Mongolia, Nepal, Pakistan, the Philippines, Thailand, and Vietnam.

METHODS

From January 1, 2014, to February 12, 2022, we conducted a prospective cohort study. To estimate CAUTI incidence, the number of UC days was the denominator, and CAUTI was the numerator. To estimate CAUTI RFs, we analyzed 11 variables using multiple logistic regression.

RESULTS

84,920 patients hospitalized for 499,272 patient days acquired 869 CAUTIs. The pooled CAUTI rate per 1,000 UC-days was 3.08; for those using suprapubic-catheters (4.11); indwelling-catheters (2.65); trauma-ICU (10.55), neurologic-ICU (7.17), neurosurgical-ICU (5.28); in lower-middle-income countries (3.05); in upper-middle-income countries (1.71); at public-hospitals (5.98), at private-hospitals (3.09), at teaching-hospitals (2.04). The following variables were identified as CAUTI RFs: Age (adjusted odds ratio [aOR] = 1.01; 95% CI = 1.01-1.02; P < .0001); female sex (aOR = 1.39; 95% CI = 1.21-1.59; P < .0001); using suprapubic-catheter (aOR = 4.72; 95% CI = 1.69-13.21; P < .0001); length of stay before CAUTI acquisition (aOR = 1.04; 95% CI = 1.04-1.05; P < .0001); UC and device utilization-ratio (aOR = 1.07; 95% CI = 1.01-1.13; P = .02); hospitalized at trauma-ICU (aOR = 14.12; 95% CI = 4.68-42.67; P < .0001), neurologic-ICU (aOR = 14.13; 95% CI = 6.63-30.11; P < .0001), neurosurgical-ICU (aOR = 13.79; 95% CI = 6.88-27.64; P < .0001); public-facilities (aOR = 3.23; 95% CI = 2.34-4.46; P < .0001).

DISCUSSION

CAUTI rate and risk are higher for older patients, women, hospitalized at trauma-ICU, neurologic-ICU, neurosurgical-ICU, and public facilities. All of them are unlikely to change.

CONCLUSIONS

It is suggested to focus on reducing the length of stay and the Urinary catheter device utilization ratio, avoiding suprapubic catheters, and implementing evidence-based CAUTI prevention recommendations.

Quick Detection of Proteus and Pseudomonas in Patients' Urine and Assessing Their Antibiotic Susceptibility Using Infrared Spectroscopy and Machine Learning

Bacterial resistance to antibiotics is a primary global healthcare concern as it hampers the effectiveness of commonly used antibiotics used to treat infectious diseases. The development of bacterial resistance continues to escalate over time. Rapid identification of the infecting bacterium and determination of its antibiotic susceptibility are crucial for optimal treatment and can save lives in many cases. Classical methods for determining bacterial susceptibility take at least 48 h, leading physicians to resort to empirical antibiotic treatment based on their experience. This random and excessive use of antibiotics is one of the most significant drivers of the development of multidrug-resistant (MDR) bacteria, posing a severe threat to global healthcare. To address these challenges, considerable efforts are underway to reduce the testing time of taxonomic classification of the infecting bacterium at the species level and its antibiotic susceptibility determination. Infrared spectroscopy is considered a rapid and reliable method for detecting minor molecular changes in cells. Thus, the main goal of this study was the use of infrared spectroscopy to shorten the identification and the susceptibility testing time of Proteus mirabilis and Pseudomonas aeruginosa from 48 h to approximately 40 min, directly from patients' urine samples. It was possible to identify the Proteus mirabilis and Pseudomonas aeruginosa species with 99% accuracy and, simultaneously, to determine their susceptibility to different antibiotics with an accuracy exceeding 80%.

Use of Female External Urinary Catheters in a Burn Intensive Care Unit: Benefits and Challenges

BACKGROUND

Burn patients have a relatively high rate of indwelling Foley catheter use because of their need for complex fluid management and wound care. However, Foley catheter use is associated with risks, including urinary tract infection. For female patients, an external urinary catheter is an alternative.

OBJECTIVES

To evaluate the use of female external urinary catheters in a burn intensive care unit and to develop a standard protocol.

METHODS

This study involved female patients admitted to a burn intensive care unit from 2017 to 2020. An initiative to increase the use of female external urinary catheters was begun in 2019. A retrospective review of medical records was used to determine rates of indwelling and external catheter use and of catheter-associated urinary tract infection before and after implementation of the initiative.

RESULTS

Of 77 female burn patients admitted to the unit between 2019 and 2020, 56 (73%) required indwelling Foley catheterization, a significant decrease from 94% before the initiative (P = .002). The mean duration of indwelling Foley catheter use decreased significantly from 19.4 days to 10.47 days (P = .049). Female external urinary catheters were used in 21 patients (27%). No patients with female external urinary catheters contracted urinary tract infections, compared with 9 patients with indwelling Foley catheters.

CONCLUSION

The use of female external urinary catheters may help reduce the risk of urinary tract infection in female burn patients. Further research is needed to refine the protocol for use of these devices and determine their safety profile.

Frequency and Impact of Infectious Disease Conditions Diagnosed During Decompensated Heart Failure Hospitalizations in the United States

There are limited data on the frequency of diagnosis of infectious disease and its impact on patients hospitalized with decompensated heart failure. We sought to evaluate the prevalence, types, trends, and outcomes of infectious disease diagnosis in patients admitted with decompensated heart failure. We performed a retrospective cohort study in patients admitted with a primary diagnosis of heart failure using the National Inpatient Sample database from 2009 to 2019. Patients with a length of stay ≥3 days were included. Patients with chronic dialysis, left ventricular assist devices, cardiogenic shock, or solid organ transplantation or who required mechanical ventilation or mechanical circulatory support were excluded. Patients were stratified according to the presence or absence of infectious disease diagnosis. Outcomes of interest were in-hospital mortality, length of stay, and resource utilization. Among the 7,228,521 admissions with a primary diagnosis of heart failure that met the inclusion and exclusion criteria, an infectious disease diagnosis was reported in 1,806,514 (24.9%). Infectious disease diagnosis was more frequent in patients who were female, older, and White, and who had higher baseline co-morbidity. Since 2014, there has been a steady decrease in infectious conditions in patients admitted with a primary diagnosis of heart failure (p for trend <0.01). After propensity match analysis was performed, patients with infectious disease diagnosis had a longer length of stay (6.9 vs 5.7 days, p <0.001) and higher cost ($14,305 vs $11,760, p <0.001), were less likely to be discharged home (35.3% vs 44.7%, p <0.001), and had higher in-hospital mortality (2.6% vs 1.6%, p <0.001). In conclusion, approximately 1 in 4 patients admitted with primary heart failure will be diagnosed with an infectious condition. The presence of an infectious disease diagnosis is associated with increased morbidity and mortality.

Rapid determination of Proteus mirabilis susceptibility to antibiotics using infrared spectroscopy in tandem with random forest

Bacterial infections cause serious illnesses that are treated with antibiotics. Currently used methods for detecting bacterial antibiotic susceptibility consume 48-72 h, leading to overuse of antibiotics. Thus, many bacterial species have acquired resistance to a broad range of available antibiotics. There is an urgent need to develop efficient methods for rapid determination of bacterial susceptibility to antibiotics. The combination of machine learning and Fourier-transform infrared (FTIR) spectroscopy has generated a promising diagnostic approach in medicine and biology. Our main goal is to examine the potential of FTIR spectroscopy to determine the susceptibility of urinary tract infection-Proteus mirabilis to a specific range of antibiotics, within about 20 min after 24 h culture and identification. We measured the infrared spectra of 489 different P. mirabilis isolates and used random forest to analyze this spectral database. A classification success rate of ~84% was achieved in differentiating between the resistant and sensitive isolates based on their susceptibility to ceftazidime, ceftriaxone, cefuroxime, cefuroxime axetil, cephalexin, ciprofloxacin, gentamicin, and sulfamethoxazole antibiotics in a time span of 24 h instead of 48 h.

Antimicrobial Resistance and Virulence Factors of Proteus mirabilis Isolated from Dog with Chronic Otitis Externa

Otitis externa is among the most prevalent diseases in dogs. If the underlying cause is not addressed, bacterial reinfection becomes frequent, necessitating antibiotic administration for an extended period of time. Prolonged treatment promotes the emergence of antibiotic-resistant bacteria and increases the risk of their transmission from animals to humans. This study aimed to analyze the antibiotic resistance pattern of the emerging pathogen Proteus mirabilis to identify bacterial virulence and antibiotic selection. Samples were collected from randomly encountered dogs with chronic otitis externa. Thirty-two strains of P. mirabilis were isolated and identified, using MALDI-TOF. The Kirby-Bauer disk diffusion method was used to assess the antibiotic susceptibility of P. mirabilis to 11 antibiotics. The isolates (n = 32) were most resistant to cefazolin (75%), trimethoprim–sulfamethoxazole (72%), chloramphenicol (72%), amoxicillin–clavulanate (63%), ampicillin (59%), cefepime (56%), ciprofloxacin (53%), aztreonam (50%), ceftazidime avibactam (50%), gentamicin (22%), and amikacin (16%). Moreover, 75% of isolates were found to be multidrug-resistant bacteria. P. mirabilis was found to have a high resistance-pattern ratio. Although the exact cause is unknown, continuous antibiotic use is thought to be a major factor. We concluded that antibiotic use must be prudent and selective to prevent antibiotic resistance.

Antibiotic Resistance in Proteus mirabilis: Mechanism, Status, and Public Health Significance

Proteus mirabilis is a specific opportunistic pathogen of many infections including urinary tract infections (UTIs). Risk factors are linked with the acquisition of multidrug-resistant (MDR) to 3 or more classes of antimicrobials) strains. The resistance in extended-spectrum alpha-lactamase is rare, but the rising resistance in extended-spectrum beta-lactamase (ESBL) producing strains is a matter of concern. β-lactamases and antibiotic modifying enzymes mainly constitute the ESBLs resistance mechanism by hydrolyzing the antibiotics. Mutation or Porin loss could lead to the reduced permeability of antibiotics, enhanced efflux pump activity hindering the antibiotic access to the target site, antibiotic failure to bind at the target site because of the target modification, and lipopolysaccharide mutation causing the resistance against polymyxin antibiotics. This review aimed to explore various antimicrobial resistance mechanisms in Proteus mirabilis and their impact on public health status.

Prospective assessment of catheter-associated bacteriuria clinical presentation, epidemiology, and colonization dynamics in nursing home residents

BACKGROUND

Catheterization facilitates continuous bacteriuria, for which the clinical significance remains unclear. This study aimed to determine the clinical presentation, epidemiology, and dynamics of bacteriuria in a cohort of long-term catheterized nursing home residents.

METHODS

Prospective urine culture, urinalysis, chart review, and assessment of signs and symptoms of infection were performed weekly for 19 study participants over 7 months. All bacteria ≥ 1 × 10³ cfu/mL were cultured, isolated, identified, and tested for susceptibility to select antimicrobials.

RESULTS

In total, 226 of the 234 urine samples were polymicrobial (97%), with an average of 4.7 isolates per weekly specimen. A total of 228 urine samples (97%) exhibited ≥ 1 × 10⁶ CFU/mL, 220 (94%) exhibited abnormal urinalysis, 126 (54%) were associated with at least 1 possible sign or symptom of infection, and 82 (35%) would potentially meet a standardized definition of catheter-associated urinary tract infection (CAUTI), but only 3 had a caregiver diagnosis of CAUTI. Bacterial isolates (286; 30%) were resistant to a tested antimicrobial agent, and bacteriuria composition was remarkably stable despite a combined total of 54 catheter changes and 23 weeks of antimicrobial use.

CONCLUSION

Bacteriuria composition was largely polymicrobial, including persistent colonization by organisms previously considered to be urine culture contaminants. Neither antimicrobial use nor catheter changes sterilized the urine, at most resulting in transient reductions in bacterial burden followed by new acquisition of resistant isolates. Thus, this patient population exhibits a high prevalence of bacteriuria coupled with potential indicators of infection, necessitating further exploration to identify sensitive markers of true infection.

FUNDING

This work was supported by the NIH (R00 DK105205, R01 DK123158, UL1 TR001412).

Catalase Activity is Critical for Proteus mirabilis Biofilm Development, EPS Composition, and Dissemination During Catheter-Associated Urinary Tract Infection

Proteus mirabilis is a leading uropathogen of catheter-associated urinary tract infections (CAUTIs), which are among the most common healthcare-associated infections worldwide. A key factor that contributes to P. mirabilis pathogenesis and persistence during CAUTI is the formation of catheter biofilms, which provide increased resistance to antibiotic treatment and host defense mechanisms. Another factor that is important for bacterial persistence during CAUTI is the ability to resist reactive oxygen species (ROS), such as through the action of the catalase enzyme. Potent catalase activity is one of the defining biochemical characteristics of P. mirabilis, and the single catalase gene (katA) encoded in strain HI4320 was recently identified as a candidate fitness factor for UTI, CAUTI, and bacteremia. Here we show that disruption of katA results in increased ROS levels, increased sensitivity to peroxide, and decreased biofilm biomass. The biomass defect was due to a decrease in extracellular polymeric substances (EPS) production by the ΔkatA mutant, and specifically due to reduced carbohydrate content. Importantly, the biofilm defect resulted in decreased antibiotic resistance in vitro and a colonization defect during experimental CAUTI. The ΔkatA mutant also exhibited decreased fitness in a bacteremia model, supporting a dual role for catalase in P. mirabilis biofilm development and immune evasion.

Effectiveness of meatal cleaning in the prevention of catheter-associated urinary tract infections and bacteriuria: an updated systematic review and meta-analysis

OBJECTIVE

A systematic review on meatal cleaning prior to urinary catheterisation and post catheterisation and reduces the risk catheter-associated urinary tract infections (CAUTIs) and bacteriuria was published in 2017, with further studies undertaken since this time. The objective of this paper is to present an updated systematic review on the effectiveness of antiseptic cleaning of the meatal area for the prevention of CAUTIs and bacteriuria in patients who receive a urinary catheter.

DESIGN

Systematic review.

DATA SOURCES

Electronic databases Cochrane Library, PubMed, Embase, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medline and Academic Search Complete were searched from 1 January 2016 and 29 February 2020.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) and quasi-experimental studies evaluating the use of antiseptic, antibacterial or non-medicated agents for cleaning the meatal, periurethral or perineal areas before indwelling catheter insertion or intermittent catheterisation or during routine meatal care.

DATA EXTRACTION AND SYNTHESIS

Data were extracted using the Cochrane Collaboration's data collection form for RCTs and non-RCTs. Data were extracted by one researcher and then checked for accuracy by a second researcher.

RESULTS

A total of 18 studies were included. Some potential benefit of using antiseptics, compared with non-antiseptics for meatal cleaning to prevent bacteriuria and or CAUTI was identified (OR 0.84, 95% CI 0.69 to 1.02; p=0.071). Antiseptics (chlorhexidine or povidine-iodine) may be of value for meatal cleaning on the incidence of CAUTI, compared with comparator agents (saline, soap or antimicrobial cloths) (OR=0.65, 95% CI 0.42 to 0.99; p=0.047).

CONCLUSION

There is emerging evidence of the role of some specific antiseptics (chlorhexidine) prior to urinary catheterisation, in reducing CAUTIs, and some potential benefit to the role of antiseptics more generally in reducing bacteriuria.

PROSPERO REGISTRATION NUMBER

CRD42015023741.

Association of Stratification by Proportion of Patients Dually Enrolled in Medicare and Medicaid With Financial Penalties in the Hospital-Acquired Condition Reduction Program

Importance

The Hospital-Acquired Condition Reduction Program (HACRP) is a value-based payment program focused on safety events. Prior studies have found that the program disproportionately penalizes safety-net hospitals, which may perform more poorly because of unmeasured severity of illness rather than lower quality. A similar program, the Hospital Readmissions Reduction Program, stratifies hospitals into 5 peer groups for evaluation based on the proportion of their patients dually enrolled in Medicare and Medicaid, but the effect of stratification on the HACRP is unknown.

Objective

To characterize the hospitals penalized by the HACRP and the distribution of financial penalties before and after stratification.

Design, Setting, and Participants

This economic evaluation used publicly available data on HACRP performance and penalties merged with hospital characteristics and cost reports. A total of 3102 hospitals participating in the HACRP in fiscal year 2020 (covering data from July 1, 2016, to December 31, 2018) were studied.

Exposures

Hospitals were divided into 5 groups based on the proportion of patients dually enrolled, and penalties were assigned to the lowest-performing quartile of hospitals in each group rather than the lowest-performing quartile overall.

Main Outcomes and Measures

Penalties in the prestratification vs poststratification schemes.

Results

The study identified 3102 hospitals evaluated by the HACRP. Safety-net hospitals received $111 333 384 in penalties before stratification compared with an estimated $79 087 744 after stratification-a savings of $32 245 640. Hospitals less likely to receive penalties after stratification included safety-net hospitals (33.6% penalized before stratification vs 24.8% after stratification, Δ = -8.8 percentage points [pp], P < .001), public hospitals (34.1% vs 30.5%, Δ = -3.6 pp, P = .003), hospitals in the West (26.8% vs 23.2%, Δ = -3.6 pp, P < .001), hospitals in Medicaid expansion states (27.3% vs 25.6%, Δ = -1.7 pp, P = .003), and hospitals caring for the most patients with disabilities (32.2% vs 28.3%, Δ = -3.9 pp, P < .001) and from racial/ethnic minority backgrounds (35.1% vs 31.5%, Δ = -3.6 pp, P < .001). In multivariate analyses, safety-net status and treating patients with highly medically complex conditions were associated with higher odds of moving from penalized to nonpenalized status.

Conclusions and Relevance

This economic evaluation suggests that stratification of hospitals would be associated with a narrowing of disparities in penalties and a marked reduction in penalties for safety-net hospitals. Policy makers should consider adopting stratification for the HACRP.

Polymicrobial interactions in the urinary tract: is the enemy of my enemy my friend?

The vast majority of research pertaining to urinary tract infection has focused on a single pathogen in isolation, and predominantly Escherichia coli. However, polymicrobial urine colonization and infection are prevalent in several patient populations, including individuals with urinary catheters. The progression from asymptomatic colonization to symptomatic infection and severe disease is likely shaped by interactions between traditional pathogens as well as constituents of the normal urinary microbiota. Recent studies have begun to experimentally dissect the contribution of polymicrobial interactions to disease outcomes in the urinary tract, including their role in development of antimicrobial-resistant biofilm communities, modulating the innate immune response, tissue damage, and sepsis. This review aims to summarize the epidemiology of polymicrobial urine colonization, provide an overview of common urinary tract pathogens, and present key microbe-microbe and host-microbe interactions that influence infection progression, persistence, and severity.

Short-term urinary catheters and their risks: an integrated systematic review

This thematic review was part of a bigger literature review into the effects of short-term urinary catheters on patients who are discharged home from an acute hospital. This integrated review examined the risks associated with short-term urinary catheters. The MEDLINE, British Nursing Index and CINAHL databases were searched for studies published between 2013 and 2018 that researched the effects of short-term urinary catheters on patients. Twelve research studies were included, which showed the presence of short-term indwelling urinary catheters increased the risk of infection, length of hospital stay and mortality rates. Short-term urinary catheters should be strictly monitored and removed as soon as they are not required.

Short-term urinary catheters and their risks: an integrated systematic review

Background:

This thematic review was part of a bigger literature review into the effects of short-term urinary catheters on patients who are discharged home from an acute hospital.

Aims:

This integrated review examined the risks associated with short-term urinary catheters.

Methods:

The MEDLINE, British Nursing Index and CINAHL databases were searched for studies published between 2013 and 2018 that researched the effects of short-term urinary catheters on patients.

Findings:

Twelve research studies were included, which showed the presence of short-term indwelling urinary catheters increased the risk of infection, length of hospital stay and mortality rates.

Conclusion:

Short-term urinary catheters should be strictly monitored and removed as soon as they are not required.

Urinary tract infections: microbial pathogenesis, host-pathogen interactions and new treatment strategies

Urinary tract infections (UTIs) are common, recurrent infections that can be mild to life-threatening. The continued emergence of antibiotic resistance, together with our increasing understanding of the detrimental effects conferred by broad-spectrum antibiotic use on the health of the beneficial microbiota of the host, has underscored the weaknesses in our current treatment paradigm for UTIs. In this Review, we discuss how recent microbiological, structural, genetic and immunological studies have expanded our understanding of host-pathogen interactions during UTI pathogenesis. These basic scientific findings have the potential to shift the strategy for UTI treatment away from broad-spectrum antibiotics targeting conserved aspects of bacterial replication towards pathogen-specific antibiotic-sparing therapeutics that target core determinants of bacterial virulence at the host-pathogen interface.

Pathophysiology, Treatment, and Prevention of Catheter-Associated Urinary Tract Infection

Urinary tract infections (UTIs) are among the most common microbial infections in humans and represent a substantial burden on the health care system. UTIs can be uncomplicated, as when affecting healthy individuals, or complicated, when affecting individuals with compromised urodynamics and/or host defenses, such as those with a urinary catheter. There are clear differences between uncomplicated UTI and catheter-associated UTI (CAUTI) in clinical manifestations, causative organisms, and pathophysiology. Therefore, uncomplicated UTI and CAUTI cannot be approached similarly, or the risk of complications and treatment failure may increase. It is imperative to understand the key aspects of each condition to develop successful treatment options and improve patient outcomes. Here, we will review the epidemiology, pathogen prevalence, differential mechanisms used by uropathogens, and treatment and prevention of uncomplicated UTI and CAUTI.

Variations in indwelling urinary catheter use in four Australian acute care hospitals

AIMS AND OBJECTIVES

To identify the point prevalence of indwelling urinary catheters (IDCs) in adult inpatients in acute care hospitals, and to describe the indications for IDC insertion based on patient age, gender, specialty and hospital.

BACKGROUND

Catheter-associated urinary tract infections (CAUTIs) are preventable healthcare-associated infections. IDC duration is the strongest predictor of CAUTI, and little is known about characteristics of patients who receive an IDC.

DESIGN

Two single-day point prevalence surveys collected baseline patient data as part of a larger pre-post control-intervention study.

METHODS

Surveys were conducted at four acute care hospitals in NSW, Australia, for all adult patients. Data collection included IDC presence, insertion details and urine culture collection. Point prevalence data were linked with electronically extracted patient demographic data. This study is presented in line with STROBE checklist (See Supplementary File 1).

RESULT

Data from 1,630 patients were analysed, with 196 patients (12%) identified as having an IDC on the survey dates. IDC prevalence rates were higher in males (13%) than in females (11%). Critical care had the highest rate of patients with IDCs (42%). Urine cultures were collected in 70 patients with an IDC (43%).

CONCLUSIONS

Findings indicated similar rates of IDC use in males and females, and there was no significant difference in age between patients with or without an IDC. However, indication for IDC varied by patient age and gender. High rates of urine culture collection may represent routine collection.

RELEVANCE TO CLINICAL PRACTICE

IDC use is found across genders, all age groups and specialties. Nurses should be aware that any of their patients may have an IDC and be particularly aware of certain indications based on patient age and gender. Routine urine culture collection is not advised, and instead, nurses should be guided by clinical decision-making tools.

Characteristics of pathogens and mortality predictors of older Chinese patients with nosocomial urinary tract infections

AIM

The aim of the present study was to investigate predominant pathogens and predictors of 28-day mortality of older Chinese patients with nosocomial urinary tract infections (NUTI).

METHODS

We retrospectively studied 1122 older patients (aged ≥60 years) with culture-positive NUTI in Guangdong General Hospital, Guangzhou, China, from January 2009 to December 2014. The clinical features, microbial distributions and outcomes of these patients were recorded and compared between survival and death patients. Multivariate logistic regression was carried out to identify independent predictors of 28-day mortality.

RESULTS

The present results showed the all-cause mortality was 8.3%, and NUTI mortality was 1.43%. The proportions of Candida albicans (P = 0.004), Acinetobacter baumannii (P = 0.045) and Candida tropicalis (P < 0.001) in the death group were significantly higher than those in the survival group. Multivariate analysis showed two novel risk factors for mortality of older patients with NUTI, which were higher Charlson Comorbidity Index (odds ratio [OR] 1.205, 95% confidence interval (CI) 1.088-1.334] and lower level of serum prealbumin (OR 0.995, 95% CI 0.990-0.999). Furthermore, previous use of antibiotics (OR 1.984, 95% CI 1.106-3.559), inappropriate antimicrobial therapy (OR 1.883, 95% CI 1.144-3.098), intensive care unit stay (OR 4.082, 95% CI 2.469-6.749) and higher concentration of serum C-reactive protein (OR 1.005, 95% CI 1.001-1.010) were independent prognostic factors for 28-day mortality in older patients with NUTI.

CONCLUSIONS

NUTI is associated with a high 28-day in-hospital mortality rate in older patients. We should evaluate the comorbidity, nutritional status, inflammatory markers, department staying and drug sensitivity test, and choose systematic therapy strategies for these older patients with NUTI. Geriatr Gerontol Int 2019; 19: 541-546.

Twin arginine translocation, ammonia incorporation, and polyamine biosynthesis are crucial for Proteus mirabilis fitness during bloodstream infection

The Gram-negative bacterium Proteus mirabilis is a common cause of catheter-associated urinary tract infections (CAUTI), which can progress to secondary bacteremia. While numerous studies have investigated experimental infection with P. mirabilis in the urinary tract, little is known about pathogenesis in the bloodstream. This study identifies the genes that are important for survival in the bloodstream using a whole-genome transposon insertion-site sequencing (Tn-Seq) approach. A library of 50,000 transposon mutants was utilized to assess the relative contribution of each non-essential gene in the P. mirabilis HI4320 genome to fitness in the livers and spleens of mice at 24 hours following tail vein inoculation compared to growth in RPMI, heat-inactivated (HI) naïve serum, and HI acute phase serum. 138 genes were identified as ex vivo fitness factors in serum, which were primarily involved in amino acid transport and metabolism, and 143 genes were identified as infection-specific in vivo fitness factors for both spleen and liver colonization. Infection-specific fitness factors included genes involved in twin arginine translocation, ammonia incorporation, and polyamine biosynthesis. Mutants in sixteen genes were constructed to validate both the ex vivo and in vivo results of the transposon screen, and 12/16 (75%) exhibited the predicted phenotype. Our studies indicate a role for the twin arginine translocation (tatAC) system in motility, translocation of potential virulence factors, and fitness within the bloodstream. We also demonstrate the interplay between two nitrogen assimilation pathways in the bloodstream, providing evidence that the GS-GOGAT system may be preferentially utilized. Furthermore, we show that a dual-function arginine decarboxylase (speA) is important for fitness within the bloodstream due to its role in putrescine biosynthesis rather than its contribution to maintenance of membrane potential. This study therefore provides insight into pathways needed for fitness within the bloodstream, which may guide strategies to reduce bacteremia-associated mortality.

Pathogenesis of Proteus mirabilis Infection

Proteus mirabilis, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs) that are often polymicrobial. These infections may be accompanied by urolithiasis, the development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. Repressors of motility are often encoded by these fimbrial operons. Motility is mediated by flagella encoded on a single contiguous 54-kb chromosomal sequence. On agar plates, P. mirabilis undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. When swarms from different strains meet, a line of demarcation, a "Dienes line," develops due to the killing action of each strain's type VI secretion system. During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending urinary tract infections or CAUTIs using both single-species and polymicrobial models. Global gene expression studies performed in culture and in the murine model have revealed the unique metabolism of this bacterium. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances.

Risk factors of mortality in patients with purple urine bag syndrome

Aim: Purple urine bag syndrome (PUBS) is rarely seen in clinical practice. Several studies have reported that PUBS is relatively benign in its clinical course, but this study aimed to identify risk factors for mortality related to PUBS. Materials and methods: In a PubMed search from October 1980 to August 2016, using the search term "Purple urine bag syndrome (PUBS)", 106 articles (n = 174 cases) were identified. This study excluded 58 cases. Among them, 14 cases did not include information on patient sex and four cases did not include information on patient age. Thirty-seven cases did not report the white blood cell (WBC) count, shock, fever, or etiology. Three cases did not report patient survival. This study considered 116 PUBS cases. Chi-square tests were used to compare the survival and mortality groups. Results: In relative risk analysis, uremia (17.8), shock (14.4), diabetes (4.8), leukocytosis (1.1), and female sex (1.1) were significant risk factors for mortality after PUBS. However, it is possible that PUBS cases are under-reported worldwide. Conclusions: PUBS is a warning sign of a urinary tract infection, and it often follows a relatively benign clinical course. This study found that female sex, leukocytosis, shock at presentation, comorbidity with diabetes, and uremia are risk factors for mortality associated with PUBS.

d-Serine Degradation by Proteus mirabilis Contributes to Fitness during Single-Species and Polymicrobial Catheter-Associated Urinary Tract Infection

Urinary tract infections are among the most common health care-associated infections worldwide, the majority of which involve a urinary catheter (CAUTI). Our recent investigation of CAUTIs in nursing home residents identified Proteus mirabilis, Enterococcus species, and Escherichia coli as the three most common organisms. These infections are also often polymicrobial, and we identified Morganella morganii, Enterococcus species, and Providencia stuartii as being more prevalent during polymicrobial CAUTI than single-species infection. Our research therefore focuses on identifying “core” fitness factors that are highly conserved in P. mirabilis and that contribute to infection regardless of the presence of these other organisms. In this study, we determined that the ability to degrade d-serine, the most abundant d-amino acid in urine and serum, strongly contributes to P. mirabilis fitness within the urinary tract, even when competing for nutrients with another organism. d-Serine uptake and degradation therefore represent potential targets for disruption of P. mirabilis infections.

Proteus mirabilis is a common cause of catheter-associated urinary tract infection (CAUTI) and secondary bacteremia, which are frequently polymicrobial. We previously utilized transposon insertion-site sequencing (Tn-Seq) to identify novel fitness factors for colonization of the catheterized urinary tract during single-species and polymicrobial infection, revealing numerous metabolic pathways that may contribute to P. mirabilis fitness regardless of the presence of other cocolonizing organisms. One such “core” fitness factor was d-serine utilization. In this study, we generated isogenic mutants in d-serine dehydratase (dsdA), d-serine permease (dsdX), and the divergently transcribed activator of the operon (dsdC) to characterize d-serine utilization in P. mirabilis and explore the contribution of this pathway to fitness during single-species and polymicrobial infection. P. mirabilis was capable of utilizing either d- or l-serine as a sole carbon or nitrogen source, and dsdA, dsdX, and dsdC were each specifically required for d-serine degradation. This capability was highly conserved among P. mirabilis isolates, although not universal among uropathogens: Escherichia coli and Morganella morganii utilized d-serine, while Providencia stuartii and Enterococcus faecalis did not. d-Serine utilization did not contribute to P. mirabilis growth in urine ex vivo during a 6-h time course but significantly contributed to fitness during single-species and polymicrobial CAUTI during a 96-h time course, regardless of d-serine utilization by the coinfecting isolate. d-Serine utilization also contributed to secondary bacteremia during CAUTI as well as survival in a direct bacteremia model. Thus, we propose d-serine utilization as a core fitness factor in P. mirabilis and a possible target for disruption of infection.

IMPORTANCE Urinary tract infections are among the most common health care-associated infections worldwide, the majority of which involve a urinary catheter (CAUTI). Our recent investigation of CAUTIs in nursing home residents identified Proteus mirabilis, Enterococcus species, and Escherichia coli as the three most common organisms. These infections are also often polymicrobial, and we identified Morganella morganii, Enterococcus species, and Providencia stuartii as being more prevalent during polymicrobial CAUTI than single-species infection. Our research therefore focuses on identifying “core” fitness factors that are highly conserved in P. mirabilis and that contribute to infection regardless of the presence of these other organisms. In this study, we determined that the ability to degrade d-serine, the most abundant d-amino acid in urine and serum, strongly contributes to P. mirabilis fitness within the urinary tract, even when competing for nutrients with another organism. d-Serine uptake and degradation therefore represent potential targets for disruption of P. mirabilis infections.

Risk factors of mortality in patients with purple urine bag syndrome

Aim: Purple urine bag syndrome (PUBS) is rarely seen in clinical practice. Several studies have reported that PUBS is relatively benign in its clinical course, but this study aimed to identify risk factors for mortality related to PUBS. Materials and methods: In a PubMed search from October 1980 to August 2016, using the search term "Purple urine bag syndrome (PUBS)", 106 articles (n = 174 cases) were identified. This study excluded 58 cases. Among them, 14 cases did not include information on patient sex and four cases did not include information on patient age. Thirty-seven cases did not report the white blood cell (WBC) count, shock, fever, or etiology. Three cases did not report patient survival. This study considered 116 PUBS cases. Chi-square tests were used to compare the survival and mortality groups. Results: In relative risk analysis, uremia (17.8), shock (14.4), diabetes (4.8), leukocytosis (1.1), and female sex (1.1) were significant risk factors for mortality after PUBS. However, it is possible that PUBS cases are under-reported worldwide. Conclusions: PUBS is a warning sign of a urinary tract infection, and it often follows a relatively benign clinical course. This study found that female sex, leukocytosis, shock at presentation, comorbidity with diabetes, and uremia are risk factors for mortality associated with PUBS.

Urine Cytokine and Chemokine Levels Predict Urinary Tract Infection Severity Independent of Uropathogen, Urine Bacterial Burden, Host Genetics, and Host Age

Urinary tract infections (UTIs) are among the most common infections worldwide. Diagnosing UTIs in older adults poses a significant challenge as asymptomatic colonization is common. Identification of a noninvasive profile that predicts likelihood of progressing from urine colonization to severe disease would provide a significant advantage in clinical practice. We monitored colonization susceptibility, disease severity, and immune response to two uropathogens in two mouse strains across three age groups to identify predictors of infection outcome. Proteus mirabilis caused more severe disease than Escherichia coli, regardless of mouse strain or age, and was associated with differences in interleukin-1β (IL-1β), beta interferon (IFN-β), CXCL5 (LIX), CCL5 (RANTES), and CCL2 (MCP-1). In a comparison of responses to infection across age groups, mature adult mice were better able to control colonization and prevent progression to kidney colonization and bacteremia than young or aged mice, regardless of mouse strain or bacterial species, and this was associated with differences in IL-23, CXCL1, and CCL5. A bimodal distribution was noted for urine colonization, which was strongly associated with bladder CFU counts and the magnitude of the immune response but independent of age or disease severity. To determine the value of urine cytokine and chemokine levels for predicting severe disease, all infection data sets were combined and subjected to a series of logistic regressions. A multivariate model incorporating IL-1β, CXCL1, and CCL2 had strong predictive value for identifying mice that did not develop kidney colonization or bacteremia, regardless of mouse genetic background, age, infecting bacterial species, or urine bacterial burden. In conclusion, urine cytokine profiles could potentially serve as a noninvasive decision support tool in clinical practice and contribute to antimicrobial stewardship.

Anti-Adherent Biomaterials for Prevention of Catheter Biofouling

Medical device-associated infections present a leading global healthcare challenge, and effective strategies to prevent infections are urgently required. Herein, we present an innovative anti-adherent hydrogel copolymer as a candidate catheter coating with complementary hydrophobic drug-carrying and eluting capacities. The amphiphilic block copolymer, Poloxamer 188, was chemically-derivatized with methacryloyl moieties and copolymerized with the hydrogel monomer, 2-hydroxyethyl methacrylate. Performance of the synthesized copolymers was evaluated in terms of equilibrium swelling, surface water wettability, mechanical integrity, resistance to encrustation and bacterial adherence, and ability to control release of the loaded fluoroquinolone antibiotic, ofloxacin. The developed matrices were able to provide significant protection from fouling, with observed reductions of over 90% in both adherence of the common urinary pathogen Escherichia coli and encrusting crystalline deposits of calcium and magnesium salts relative to the commonly employed hydrogel, poly (hydroxyethyl methacrylate). Additionally, the release kinetics of a loaded hydrophobic drug could be readily tuned through facile manipulation of polymer composition. This combinatorial approach shows significant promise in the development of suitable systems for prevention of catheter-associated infections.

Avoidance of urinary catheterization to minimize in-hospital complications after transcatheter aortic valve implantation: An observational study

Background:

Contemporary transcatheter aortic valve implantation (TAVI) devices and approach present opportunities to review historical practices initially informed by early treatment development and cardiac surgery. The avoidance of urinary catheterization in the older TAVI population is a strategy to minimize in-hospital complications. The purpose of the study was to explore elimination-related complications following the phased implementation of a default strategy of avoiding urinary catheterization in patients undergoing transfemoral (TF) TAVI.

Methods:

We conducted an observational study using a retrospective chart review of patients treated between 2011 and 2013 to identify patient characteristics, peri-procedure details, in-hospital outcomes and elimination-related complications in patients who did or did not receive a peri-procedure indwelling catheter. Descriptive analyses were used to report differences between the groups; we conducted a regression analysis to explore the relationship between the practice of urinary catheterization and total procedure time.

Results:

Of the 408 patients who underwent TF TAVR, 188 (46.1%) received a peri-procedure indwelling urinary catheter and 220 (53.9%) did not. There was no difference in in-hospital mortality (2.2%), disabling stroke (0.5%), or other major cardiac adverse events. The avoidance of a urinary catheter resulted in significantly lower rates of urinary tract infection requiring a new antibiotic regimen (1.4% versus 6.1%, p = 0.014), haematuria documented by medicine or nursing (3.7% versus 17.6%, p = 0.001), and the need for continuous bladder irrigation (2.7% versus 0%, p = 0.027).

Conclusion:

The avoidance of a urinary catheter may contribute to improved outcomes in patients undergoing TAVI. The intervention should be further evaluated within the broader study of minimalist TAVI.

The Pathogenic Potential of Proteus mirabilis Is Enhanced by Other Uropathogens during Polymicrobial Urinary Tract Infection

Urinary catheter use is prevalent in health care settings, and polymicrobial colonization by urease-positive organisms, such as Proteus mirabilis and Providencia stuartii, commonly occurs with long-term catheterization. We previously demonstrated that coinfection with P. mirabilis and P. stuartii increased overall urease activity in vitro and disease severity in a model of urinary tract infection (UTI). In this study, we expanded these findings to a murine model of catheter-associated UTI (CAUTI), delineated the contribution of enhanced urease activity to coinfection pathogenesis, and screened for enhanced urease activity with other common CAUTI pathogens. In the UTI model, mice coinfected with the two species exhibited higher urine pH values, urolithiasis, bacteremia, and more pronounced tissue damage and inflammation compared to the findings for mice infected with a single species, despite having a similar bacterial burden within the urinary tract. The presence of P. stuartii, regardless of urease production by this organism, was sufficient to enhance P. mirabilis urease activity and increase disease severity, and enhanced urease activity was the predominant factor driving tissue damage and the dissemination of both organisms to the bloodstream during coinfection. These findings were largely recapitulated in the CAUTI model. Other uropathogens also enhanced P. mirabilis urease activity in vitro, including recent clinical isolates of Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, and Pseudomonas aeruginosa We therefore conclude that the underlying mechanism of enhanced urease activity may represent a widespread target for limiting the detrimental consequences of polymicrobial catheter colonization, particularly by P. mirabilis and other urease-positive bacteria.

How Often Do Clinically Diagnosed Catheter-Associated Urinary Tract Infections in Nursing Homes Meet Standardized Criteria?

OBJECTIVES

To determine the relationship between clinically diagnosed catheter-associated urinary tract infection (CAUTI) and standardized criteria and to assess microorganism-level differences in symptom burden in a cohort of catheterized nursing home (NH) residents.

DESIGN

Post hoc analysis of a prospective longitudinal study.

SETTING

Twelve NHs in southeast Michigan.

PARTICIPANTS

NH residents with indwelling urinary catheters (n = 233; 90% white, 52% male, mean age 73.7).

MEASUREMENTS

Clinical and demographic data, including CAUTI epidemiology and symptoms, were obtained at study enrollment, 14 days, and monthly thereafter for up to 1 year.

RESULTS

One hundred twenty participants with an indwelling catheter (51%) were prescribed systemic antibiotics for 182 clinically diagnosed CAUTIs. Common signs and symptoms were acute change in mental status (28%), fever (21%), and leukocytosis (13%). Forty percent of clinically diagnosed CAUTIs met Loeb's minimum criteria, 32% met National Health Safety Network (NHSN) criteria, and 50% met Loeb's minimum or NHSN criteria. CAUTIs involving Staphylococcus aureus and Enterococcus spp. were least likely to meet criteria. CAUTIs involving Klebsiella pneumoniae were most likely to meet Loeb's minimum criteria (odds ratio (OR) = 9.7, 95% confidence interval (CI) = 2.3-40.3), possibly because of an association with acute change in mental status (OR = 5.9, 95% CI = 1.8-19.4).

CONCLUSION

Fifty percent of clinically diagnosed CAUTIs met standardized criteria, which represents an improvement in antibiotic prescribing practices. At the microorganism level, exploratory data indicate that symptom burden may differ between microorganisms. Exploration of CAUTI signs and symptoms associated with specific microorganisms may yield beneficial information to refine existing tools to guide appropriate antibiotic treatment.

Regional variation in urinary catheter use and catheter-associated urinary tract infection: results from a national collaborative

OBJECTIVE

To examine regional variation in the use and appropriateness of indwelling urinary catheters and catheter-associated urinary tract infection (CAUTI).

DESIGN AND SETTING

Cross-sectional study.

PARTICIPANTS

US acute care hospitals.

METHODS

Hospitals were divided into 4 regions according to the US Census Bureau. Baseline data on urinary catheter use, catheter appropriateness, and CAUTI were collected from participating units. The catheter utilization ratio was calculated by dividing the number of catheter-days by the number of patient-days. We used the National Healthcare Safety Network (NHSN) definition (number of CAUTIs per 1,000 catheter-days) and a population-based definition (number of CAUTIs per 10,000 patient-days) to calculate CAUTI rates. Logistic and Poisson regression models were used to assess regional differences.

RESULTS

Data on 434,207 catheter-days over 1,400,770 patient-days were collected from 1,101 units within 726 hospitals across 34 states. Overall catheter utilization was 31%. Catheter utilization was significantly higher in non-intensive care units (ICUs) in the West compared with non-ICUs in all other regions. Approximately 30%-40% of catheters in non-ICUs were placed without an appropriate indication. Catheter appropriateness was the lowest in the West. A total of 1,099 CAUTIs were observed (NHSN rate of 2.5 per 1,000 catheter-days and a population-based rate of 7.8 per 10,000 patient-days). The population-based CAUTI rate was highest in the West (8.9 CAUTIs per 10,000 patient-days) and was significantly higher compared with the Midwest, even after adjusting for hospital characteristics (P = .02).

CONCLUSIONS

Regional differences in catheter use, appropriateness, and CAUTI rates were detected across US hospitals.

The yin-yang driving urinary tract infection and how proteomics can enhance research, diagnostics, and treatment

Bacterial urinary tract infections (UTIs) afflict millions of people worldwide both in the community and the hospital setting. The onset, duration, and severity of infection depend on the characteristics of the invading pathogen (yin), as well as the immune response elicited by the infected individual (yang). Uropathogenic Escherichia coli (UPEC) account for the majority of UTIs, and extensive investigations by many scientific groups have elucidated an elaborate pathogenic UPEC life cycle, involving the occupation of extracellular and intracellular niches and the expression of an arsenal of virulence factors that facilitate niche occupation. This review will summarize the current knowledge on UPEC pathogenesis; the host immune responses elicited to combat infection; and it will describe proteomics approaches used to understand UPEC pathogenesis, as well as drive diagnostics and treatment options. Finally, new strategies are highlighted that could be applied toward furthering our knowledge regarding host-bacterial interactions during UTI.

Peripherally Inserted Central Catheter Use in Skilled Nursing Facilities: A Pilot Study

OBJECTIVES

To describe patterns of use, care practices, and outcomes related to peripherally inserted central catheter (PICC) use in skilled nursing facilities (SNFs).

DESIGN

Prospective cohort study.

SETTING

Two community SNFs.

PARTICIPANTS

Adult SNF residents with PICCs (N = 56).

MEASUREMENTS

Information on indication for PICC use, device characteristics (e.g., lumens, gauge), and participant data (comorbidities, medications) were obtained from medical records. Care practices (e.g., frequency of flushing, dressing care) and problems related to PICCs were recorded. Major (central line-associated bloodstream infection, venous thromboembolism, catheter dislodgement) and minor (migration, dressing disruption, lumen occlusion, exit site infection) complications and process measures (flushing of PICC, assessment of necessity) were recorded. Bivariate analyses with t-tests, chi-square tests, or Fischer exact tests were used for continuous and categorical data.

RESULTS

Participants were enrolled from two SNFs. The most common indication for PICC use was intravenous antibiotic delivery. The average PICC dwell time was 43 days, and most devices were single-lumen PICCs. Major and minor complications were common and occurred in 11 (20%) and 18 (32%) participants, respectively. Occlusion (23%, n = 13), accidental dislodgement (12%, n = 7), and dressing disruption (11%, n = 6) were the commonest complications observed. Documentation regarding catheter care practices occurred in 41% of cases.

CONCLUSION

Quality improvement efforts that seek to benchmark practice, identify gaps, and institute efforts to improve PICC care and practice in SNFs appear necessary.

Shifting trends in the incidence of Pseudomonas aeruginosa septicemia in hospitalized adults in the United States from 1996-2010

BACKGROUND

Pseudomonas aeruginosa septicemia (PAS) is associated with high mortality rates and substantial resource utilization; however, the burden of PAS in the United States in recent years is unknown.

METHODS

This was a retrospective analysis of the U.S. National Hospital Discharge Surveys from 1996-2010. Adult patients with an ICD-9-CM code for PAS (038.43) were included. Incidence, in-hospital mortality, and hospital length of stay (LOS) for PAS discharges were reported. Incidence was calculated as PAS discharges per 10,000 total adult discharges.

RESULTS

Overall, 213,553 patients had a PAS discharge diagnosis during the study period. Patients had a median (interquartile range [IQR]) age of 69 (55-78) years and were predominately men (61%) and white (75%). PAS incidence declined from 6.5 per 10,000 in 1996 to 3.1 per 10,000 in 2001 and then increased to 6.5 per 10,000 in 2010. PAS incidence was highest in the Northeast (7.6 per 10,000) and lowest in the South (6.2 per 10,000). The overall mortality rate was 16%, but this ranged from 10%-26% over the study period. Median LOS was 10 (IQR, 6-19) days, and this varied over the study period (8-13 days).

CONCLUSIONS

The incidence of PAS has increased among hospitalized adults in the United States since 2001, with little evidence of improvement in mortality or LOS.