Clinical implications for patients treated inappropriately for community-acquired pneumonia in the emergency department

Risk Factors and Outcomes Associated With Polymicrobial Infection in Community-Acquired Pneumonia

BACKGROUND

Polymicrobial pneumonia is a concern for clinicians due to its association with increased disease severity. Determining the prevalence of polymicrobial pneumonia and identifying patients who have an increased risk of this aetiology is important for the management of CAP patients. Here we describe the clinical characteristics and outcomes of adult hospitalized patients with CAP, and identify the risk factors related to polymicrobial pneumonia and specifically to 30-day mortality.

METHODS

Real-life retrospective study from a prospectively collected data including 5114 consecutive adult patients hospitalized with CAP; 1703 patients had an established aetiology.

RESULTS

Polymicrobial infection was present in 14% of the CAP patients with defined microbial aetiology (64% of ward patients and 28% of ICU patients). The most frequent polymicrobial infections were: Streptococcus pneumoniae+respiratory virus (32%), S. pneumoniae+Haemophilus influenzae (7%) and S. pneumoniae+Staphylococcus aureus (7%). Inappropriate initial antimicrobial treatment was more frequent in the polymicrobial aetiology group than in the monomicrobial aetiology group (14% vs. 7%, p=0.001). In-hospital (12% vs. 7%, p=0.012), 30-day (11% vs. 6%, p=0.008) and 1-year mortality (16% vs. 8%, p=0.001) were higher in the polymicrobial group. Multilobar pneumonia (OR 1.34, 95% CI 1.00-1.80) was an independent risk factor for polymicrobial aetiology in the multivariable analysis, while fever (OR 0.59, 95% CI 0.43-0.80) was independently associated with a lower risk for this condition. Polymicrobial infection was an independent predictor of 30-day mortality in the multivariable analysis (HR 1.83, 95% CI 1.17-2.87; p=0.008).

CONCLUSIONS

Polymicrobial infection was related to poor outcomes in adults hospitalized with CAP, especially in elderly patients with chronic comorbidities. Polymicrobial infection was a risk factor for 30-day mortality.

Impact of Gram-Negative Bacilli Resistance Rates on Risk of Death in Septic Shock and Pneumonia

Background

Sepsis is a major cause of morbidity and mortality worldwide. When selecting empiric antibiotics for sepsis, clinicians are encouraged to use local resistance rates, but their impact on individual outcomes is unknown. Improved methods to predict outcomes are needed to optimize treatment selection and improve antibiotic stewardship.

Methods

We expanded on a previously developed theoretical model to estimate the excess risk of death in gram-negative bacilli (GNB) sepsis due to discordant antibiotics using 3 factors: the prevalence of GNB in sepsis, the rate of antibiotic resistance in GNB, and the mortality difference between discordant and concordant antibiotic treatments. We focused on ceftriaxone, cefepime, and meropenem as the anti-GNB treatment backbone in sepsis, pneumonia, and urinary tract infections. We analyzed both publicly available data and data from a large urban hospital.

Results

Publicly available data were weighted toward culture-positive cases. Excess risk of death with discordant antibiotics was highest in septic shock and pneumonia. In septic shock, excess risk of death was 4.53% (95% confidence interval [CI], 4.04%-5.01%), 0.6% (95% CI, .55%-.66%), and 0.19% (95% CI, .16%-.21%) when considering resistance to ceftriaxone, cefepime, and meropenem, respectively. Results were similar in pneumonia. Local data, which included culture-negative cases, showed an excess risk of death in septic shock of 0.75% (95% CI, .57%-.93%) for treatment with discordant antibiotics in ceftriaxone-resistant infections and 0.18% (95% CI, .16%-.21%) for cefepime-resistant infections.

Conclusions

Estimating the excess risk of death for specific sepsis phenotypes in the context of local resistance rates, rather than relying on population resistance data, may be more informative in deciding empiric antibiotics in GNB infections.

Ten Issues for Updating in Community-Acquired Pneumonia: An Expert Review

Community-acquired pneumonia represents the third-highest cause of mortality in industrialized countries and the first due to infection. Although guidelines for the approach to this infection model are widely implemented in international health schemes, information continually emerges that generates controversy or requires updating its management. This paper reviews the most important issues in the approach to this process, such as an aetiologic update using new molecular platforms or imaging techniques, including the diagnostic stewardship in different clinical settings. It also reviews both the Intensive Care Unit admission criteria and those of clinical stability to discharge. An update in antibiotic, in oxygen, or steroidal therapy is presented. It also analyzes the management out-of-hospital in CAP requiring hospitalization, the main factors for readmission, and an approach to therapeutic failure or rescue. Finally, the main strategies for prevention and vaccination in both immunocompetent and immunocompromised hosts are reviewed.

Efficacy of Doxycycline for Mild-to-Moderate Community-Acquired Pneumonia in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Doxycycline has been recommended as a treatment option for non-severe community-acquired pneumonia (CAP) in adults. We sought to review the evidence for the efficacy of doxycycline in adult patients with mild-to-moderate CAP.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) of doxycycline versus comparator to assess the clinical efficacy. The primary outcome was the clinical cure rate. Random effects model meta-analyses were used to generate pooled odds ratio (OR) and evaluate heterogeneity (I2). Risk of bias (RoB) and quality of evidence (QoE) were evaluated using the Cochrane Risk of Bias 2.0 tool and GRADE methods, respectively.

RESULTS

We included 6 RCTs with 834 clinically evaluable patients. The trials were performed between 1984 and 2004. Comparators were 3 macrolides (roxithromycin, spiramycin, and erythromycin) and 3 fluoroquinolones (ofloxacin, fleroxacin, and levofloxacin). Four trials had an overall high RoB. The clinical cure rate was similar between the doxycycline and comparator groups (87.2% [381/437] vs 82.6% [328/397]; OR 1.29 [95% confidence interval {CI}: .73-2.28]; I2 = 30%; low QoE). Subgroup analysis of two studies with a low RoB showed significantly higher clinical cure rates in the doxycyline group (87.1% [196/225] vs 77.8% [165/212]; OR 1.92 [95% CI: 1.15-3.21]; P = .01; I2 = 0%). Adverse event rates were comparable between the doxycycline and comparator groups.

CONCLUSIONS

The efficacy of doxycycline was comparable to macrolides or fluoroquinolones in mild-to-moderate CAP and thus represents a viable treatment option. Considering the lack of recent trials, it warrants large-scale clinical trials.

Short-Term Readmission Following Community-Acquired Pneumonia: A Cross-Sectional Study

Background:Community-acquired pneumonia continues to be a major cause of morbidity and mortality. Hospital readmissions following community-acquired pneumonia are linked to significant cost of care and medical burdens. This study aimed to determine the incidence and reasons for readmission as well as to assess factors associated with short-term hospital readmission among community-acquired pneumonia patients. Methods:A retrospective, cross-sectional study was conducted on 582 medical records of community-acquired pneumonia inpatients from December 2018 to December 2019 at an 800-bed tertiary hospital in Ho Chi Minh City, Vietnam. We collected data on patient characteristics, pneumonia severity at hospital admission, microbiology and antibiotic resistance, appropriateness of empiric antibiotic therapies, and the readmissions information. Multivariable logistic regression analyses were performed to identify factors associated with 30-day hospital readmission. Results: Of the 582 hospitalized community-acquired pneumonia patients, 11.9% were readmitted to the hospital within 30 days. About half of the cases (43.5%) were due to pneumonia. Multidrug-resistant bacteria accounted for 43.2% of the pathogen isolates. A high Charlson comorbidity index (aOR, 1.40; CI 95%, 1.08-1.82) and multidrug-resistant infection (aOR, 2.63; CI 95%, 1.05-6.56) were associated with higher odds of all-cause readmission. Conclusions:Hospital readmissions within 30 days occurred frequently among community-acquired pneumonia inpatients, and the most common reason for readmission recorded was pneumonia-related. Monitoring closely patients with multimorbidity or multidrug-resistant infections may improve treatment outcomes.

Unmet needs in pneumonia research: a comprehensive approach by the CAPNETZ study group

Introduction

Despite improvements in medical science and public health, mortality of community-acquired pneumonia (CAP) has barely changed throughout the last 15 years. The current SARS-CoV-2 pandemic has once again highlighted the central importance of acute respiratory infections to human health. The “network of excellence on Community Acquired Pneumonia” (CAPNETZ) hosts the most comprehensive CAP database worldwide including more than 12,000 patients. CAPNETZ connects physicians, microbiologists, virologists, epidemiologists, and computer scientists throughout Europe. Our aim was to summarize the current situation in CAP research and identify the most pressing unmet needs in CAP research.

Methods

To identify areas of future CAP research, CAPNETZ followed a multiple-step procedure. First, research members of CAPNETZ were individually asked to identify unmet needs. Second, the top 100 experts in the field of CAP research were asked for their insights about the unmet needs in CAP (Delphi approach). Third, internal and external experts discussed unmet needs in CAP at a scientific retreat.

Results

Eleven topics for future CAP research were identified: detection of causative pathogens, next generation sequencing for antimicrobial treatment guidance, imaging diagnostics, biomarkers, risk stratification, antiviral and antibiotic treatment, adjunctive therapy, vaccines and prevention, systemic and local immune response, comorbidities, and long-term cardio-vascular complications.

Conclusion

Pneumonia is a complex disease where the interplay between pathogens, immune system and comorbidities not only impose an immediate risk of mortality but also affect the patients’ risk of developing comorbidities as well as mortality for up to a decade after pneumonia has resolved. Our review of unmet needs in CAP research has shown that there are still major shortcomings in our knowledge of CAP.

Ceftriaxone resistance and adequacy of initial antibiotic therapy in community onset bacterial pneumonia

Much remains unknown about the impact of initial antibiotic adequacy on mortality in community onset bacterial pneumonia (COBP). Therefore, we performed a study to determine how the adequacy of initial antibiotic therapy affects in-hospital mortality for patients with COBP.We carried out a retrospective cohort study among the 11 BJC Healthcare community and academic hospitals in Missouri and Illinois. The electronic medical records for BJC Healthcare were queried to obtain a set of patient admissions with culture positive (respiratory or blood) COBP admitted from January 1, 2016 through December 31, 2019. Patients with COBP required an International Classification of Diseases (ICD)-10 diagnostic code for pneumonia, admission to the hospital through an emergency department, a chest radiograph with an infiltrate, an abnormal white blood cell count or temperature, an order for 1 or more new antibiotics, and a positive respiratory or blood culture. Antibiotic selection was deemed adequate if the patient had organisms susceptible to at least one of the antibiotics received according to in vitro testing using standard laboratory breakpoints.Among 36,645 screened pneumonia admissions, 1843 met criteria for culture positive COBP. Eight hundred nineteen (44.4%) had ceftriaxone-resistant (CTX-R) organisms and 1024 had ceftriaxone-sensitive (CTX-S) organisms. The most common CTX-R pathogens were methicillin resistant Staphylococcus aureus (46.9%), Pseudomonas species (38.4%), and Escherichia coli (4.5%). On the day of admission 71% of all patients were given adequate antibiotic treatment (62.2% of CTX-R and 77.9% of CTX-S). Unnecessarily broad initial treatment was administered to 57.1% of CTX-S patients. In a logistic regression model accounting for comorbidities and severity of illness, inadequate therapy on the day of admission was associated with higher in-hospital mortality (P = .005). Among CTX-S patients who were adequately treated, initial use of unnecessarily broad antibiotics was associated with increased in-hospital mortality (P = .003).Ceftriaxone resistance was common in this cohort of culture positive COBP patients. Inappropriate coverage on day of admission was associated with greater likelihood of in-hospital mortality.

Antibiotic Stewardship in the Intensive Care Unit. An Official American Thoracic Society Workshop Report in Collaboration with the AACN, CHEST, CDC, and SCCM

Intensive care units (ICUs) are an appropriate focus of antibiotic stewardship program efforts because a large proportion of any hospital’s use of parenteral antibiotics, especially broad-spectrum, occurs in the ICU. Given the importance of antibiotic stewardship for critically ill patients and the importance of critical care practitioners as the front line for antibiotic stewardship, a workshop was convened to specifically address barriers to antibiotic stewardship in the ICU and discuss tactics to overcome these. The working definition of antibiotic stewardship is “the right drug at the right time and the right dose for the right bug for the right duration.” A major emphasis was that antibiotic stewardship should be a core competency of critical care clinicians. Fear of pathogens that are not covered by empirical antibiotics is a major driver of excessively broad-spectrum therapy in critically ill patients. Better diagnostics and outcome data can address this fear and expand efforts to narrow or shorten therapy. Greater awareness of the substantial adverse effects of antibiotics should be emphasized and is an important counterargument to broad-spectrum therapy in individual low-risk patients. Optimal antibiotic stewardship should not focus solely on reducing antibiotic use or ensuring compliance with guidelines. Instead, it should enhance care both for individual patients (by improving and individualizing their choice of antibiotic) and for the ICU population as a whole. Opportunities for antibiotic stewardship in common ICU infections, including community- and hospital-acquired pneumonia and sepsis, are discussed. Intensivists can partner with antibiotic stewardship programs to address barriers and improve patient care.

Pneumococal community-acquired pneumonia in the intensive care unit: Azithromycin remains protective despite macrolide resistance

BACKGROUND

Streptococcus pneumoniae (SP) remains the leading pathogen in community-acquired pneumonia (CAP). Despite the increasing prevalence of macrolide resistance in SP, guidelines recommend the use of macrolides as part of a combination regiment for intensive care unit (ICU) patients with CAP. We sought to describe if macrolide resistance effects outcomes in SP CAP in the ICU and if macrolides remain associated with a mortality advantage in an era of greater resistance.

METHODS

We identified all patients with SP CAP admitted to the ICU between January 2012 and December 2016, and hospital mortality represented the primary endpoint. We recorded markers of acute and chronic disease severity (eg, Charlson score, need for mechanical ventilation and/or vasopressors) along with infection-related variables including the presence of macrolide resistance. We compared subjects treated with azithromycin to those not given this agent.

RESULTS

The cohort included 140 subjects (89.2% on mechanical ventilation, 14.3% crude mortality). Macrolide resistance occurred often (60.8%) and, in univariate analyses, was associated with higher mortality while azithromycin use appeared linked to fewer death. In multivariate analysis controlling for multiple confounders including macrolide resistance and the timeliness and appropriateness of antibiotic therapy, treatment with azithromycin resulted in fewer death (Adjusted odds ratio 0.27, 95% confidence interval: 0.09-0.85, p = 0.024). Macrolide resistance, however, was not independently related to mortality.

CONCLUSIONS

Macrolide resistance appears frequently in SP ICU CAP. The addition of azithromycin to the antibiotic regimen in this scenario is significantly associated with a reduction in in-hospital mortality independent of multiple co-variates.

Effect of β-Lactam Plus Macrolide Versus Fluoroquinolone on 30-Day Readmissions for Community-Acquired Pneumonia

BACKGROUND

Antibiotic therapy with a macrolide and β-lactam or a fluoroquinolone for the empirical treatment of community-acquired pneumonia (CAP) in an inpatient non-intensive care setting is recommended per guidelines. Studies show that these treatments have similar outcomes, including death, adverse effects, and bacterial eradication. However, a comparison of 30-day readmission rates between these treatments is limited.

STUDY QUESTION

To determine whether 30-day readmissions for patients treated for CAP in a regional hospital differed between a fluoroquinolone monotherapy and a β-lactam plus macrolide combination therapy.

STUDY DESIGN

Retrospective cohort study of patients aged ≥18 years with a CAP diagnosis who were admitted to the same regional hospital from December 1, 2011, through December 1, 2016.

MEASURES AND OUTCOMES

Patients receiving a third-generation cephalosporin plus macrolide were compared with those receiving a respiratory fluoroquinolone. Exclusion criteria were concurrent or recent use of the study antibiotics; death, transfer, or transition to hospice; and diagnosis of hospital-acquired pneumonia or health care-associated pneumonia. The collected data were 30-day readmission rates, antibiotic regimens, demographic characteristics, and pneumonia severity index and comorbidity scores. Association between treatment group and readmissions was assessed with logistic regression. Association between readmissions and individual data points between the 2 treatment groups was calculated with multivariate regression and odds ratio (95% confidence interval).

RESULTS

Of 432 patients, 171 met inclusion criteria (fluoroquinolone group, n = 101; β-lactam plus macrolide group, n = 70). Thirty-day readmissions were not significantly different between the fluoroquinolone group and β-lactam plus macrolide group (P = 0.58). Increased 30-day readmissions were independently associated with male sex and hospital length of stay (P < 0.05). Length of stay was approximately 3 days and did not differ between treatment groups.

CONCLUSIONS

No difference was seen in 30-day readmissions between CAP patients who received fluoroquinolone monotherapy and those who received β-lactam plus macrolide combination therapy.

Species Identification and Antibiotic Resistance Prediction by Analysis of Whole-Genome Sequence Data by Use of ARESdb: an Analysis of Isolates from the Unyvero Lower Respiratory Tract Infection Trial

Whole-genome sequencing (WGS) is now routinely performed in clinical microbiology laboratories to assess isolate relatedness. With appropriately developed analytics, the same data can be used for prediction of antimicrobial susceptibility. We assessed WGS data for identification using open-source tools and antibiotic susceptibility testing (AST) prediction using ARESdb compared to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification and broth microdilution phenotypic susceptibility testing on clinical isolates from a multicenter clinical trial of the FDA-cleared Unyvero lower respiratory tract infection (LRTI) application (Curetis).

Whole-genome sequencing (WGS) is now routinely performed in clinical microbiology laboratories to assess isolate relatedness. With appropriately developed analytics, the same data can be used for prediction of antimicrobial susceptibility. We assessed WGS data for identification using open-source tools and antibiotic susceptibility testing (AST) prediction using ARESdb compared to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification and broth microdilution phenotypic susceptibility testing on clinical isolates from a multicenter clinical trial of the FDA-cleared Unyvero lower respiratory tract infection (LRTI) application (Curetis). For the trial, more than 2,000 patient samples were collected from intensive care units across nine hospitals and tested for LRTI. The isolate subset used in this study included 620 clinical isolates originating from 455 LRTI culture-positive patient samples. Isolates were sequenced using the Illumina Nextera XT protocol and FASTQ files with raw reads uploaded to the ARESdb cloud platform (ares-genetics.cloud; released for research use in 2020). The platform combines Ares Genetics’ proprietary database ARESdb with state-of-the-art bioinformatics tools and curated public data. For identification, WGS showed 99 and 93% concordance with MALDI-TOF MS at the genus and species levels, respectively. WGS-predicted susceptibility showed 89% categorical agreement with phenotypic susceptibility across a total of 129 species-compound pairs analyzed, with categorical agreement exceeding 90% in 78 species-compound pairs and reaching 100% in 32. Results of this study add to the growing body of literature showing that, with improvement of analytics, WGS data could be used to predict antimicrobial susceptibility.

XueBiJing Injection Versus Placebo for Critically Ill Patients With Severe Community-Acquired Pneumonia: A Randomized Controlled Trial

Supplemental Digital Content is available in the text.

Objectives:

To investigate whether XueBiJing injection improves clinical outcomes in critically ill patients with severe community-acquired pneumonia.

Design:

Prospective, randomized, controlled study.

Setting:

Thirty-three hospitals in China.

Patients:

A total of 710 adults 18–75 years old with severe community-acquired pneumonia.

Interventions:

Participants in the XueBiJing group received XueBiJing, 100 mL, q12 hours, and the control group received a visually indistinguishable placebo.

Measurements and Main Results:

The primary outcome was 8-day improvement in the pneumonia severity index risk rating. Secondary outcomes were 28-day mortality rate, duration of mechanical ventilation and total duration of ICU stay. Improvement in the pneumonia severity index risk rating, from a previously defined endpoint, occurred in 203 (60.78%) participants receiving XueBiJing and in 158 (46.33%) participants receiving placebo (between-group difference [95% CI], 14.4% [6.9–21.8%]; p < 0.001). Fifty-three (15.87%) XueBiJing recipients and 84 (24.63%) placebo recipients (8.8% [2.4–15.2%]; p = 0.006) died within 28 days. XueBiJing administration also decreased the mechanical ventilation time and the total ICU stay duration. The median mechanical ventilation time was 11.0 versus 16.5 days for the XueBiJing and placebo groups, respectively (p = 0.012). The total duration of ICU stay was 12 days for XueBiJing recipients versus 16 days for placebo recipients (p = 0.004). A total of 256 patients experienced adverse events (119 [35.63%] vs 137 [40.18%] in the XueBiJing and placebo groups, respectively [p = 0.235]).

Conclusions:

In critically ill patients with severe community-acquired pneumonia, XueBiJing injection led to a statistically significant improvement in the primary endpoint of the pneumonia severity index as well a significant improvement in the secondary clinical outcomes of mortality, duration of mechanical ventilation and duration of ICU stay.

Inhaled antibiotics for the treatment of pneumonia

PURPOSE OF REVIEW

To describe recent developments in trials exploring inhaled antibiotics for treating severe pneumonia.

RECENT FINDINGS

Three recent randomized studies investigated the potential role for aerosolized antibiotics for gram-negative pneumonia in ventilated patients. One single center, nonblinded investigation suggested a benefit with inhaled amikacin for resistant gram-negative infections. However, two multicenter, blinded trials found no benefit to adjunctive nebulized amikacin for severe gram-negative pneumonia.

SUMMARY

Well done clinical trials do not support the routine use of inhaled amikacin for pneumonia in ventilated patients. There may be a potential role for aerosolized antibiotics when other options are limited.

Outcomes associated with the use of a revised risk assessment strategy to predict antibiotic resistance in community-onset pneumonia: a stewardship perspective

Objectives

There is growing evidence that patients with community-onset pneumonia and recent healthcare exposure are not at equally high risk of infection with MDR organisms. An individualized approach is necessary with regard to risk assessment and choice of antibiotics.

Methods

We reviewed the records of 102 patients admitted for community-onset pneumonia, before and after the implementation of a revised risk assessment programme for MDR organisms using the drug resistance in pneumonia (DRIP) score. The primary aim of the study was to identify the effects of this intervention on antibiotic days of therapy (DOT), and secondary outcomes included all-cause readmissions and time to clinical improvement. Statistical analysis was performed using generalized linear regression and Cox hazards models.

Results

Implementation of the programme resulted in a decrease in anti-MRSA (-1.44 DOT, P = 0.007) and anti-pseudomonal (-2.03 DOT, P < 0.001) antibiotic utilization, but was not associated with a significant difference in the odds of readmissions (OR 0.64, 95% CI 0.16-2.57) or in time to clinical improvement (HR 1.19, 95% CI 0.62-2.21).

Conclusions

An individualized MDR organism risk assessment strategy using a clinical prediction score for community-onset pneumonia can decrease the utilization of broad-spectrum antibiotics without an increase in adverse outcomes.

Management of community-acquired bacterial pneumonia in adults: Limitations of current antibiotics and future therapies

Community-acquired bacterial pneumonia (CABP) is one of the leading causes of morbidity and mortality in India and worldwide. Evidence indicates that Gram-positive, Gram-negative, and atypical bacteria are encountered with near-equal frequency. Despite guideline recommendations and antibiotic options for the management of CABP, burden of morbidity and mortality is high, which is attributable to a variety of factors. Failure of empirical therapy, probably because of insufficient microbial coverage, increasing bacterial resistance, and adverse effects of existing treatments, underlies the unsuccessful treatment of CABP, especially in India. Multiple novel therapies that have entered clinical development phases have potential to address some of these issues. This article discusses the current treatment guidelines in CABP, management limitations, and emerging potential treatment options in the management of CABP.

CDS in a Learning Health Care System: Identifying Physicians' Reasons for Rejection of Best-Practice Recommendations in Pneumonia through Computerized Clinical Decision Support

BACKGROUND

Local implementation of guidelines for pneumonia care is strongly recommended, but the context of care that affects implementation is poorly understood. In a learning health care system, computerized clinical decision support (CDS) provides an opportunity to both improve and track practice, providing insights into the implementation process.

OBJECTIVES

This article examines physician interactions with a CDS to identify reasons for rejection of guideline recommendations.

METHODS

We implemented a multicenter bedside CDS for the emergency department management of pneumonia that integrated patient data with guideline-based recommendations. We examined the frequency of adoption versus rejection of recommendations for site-of-care and antibiotic selection. We analyzed free-text responses provided by physicians explaining their clinical reasoning for rejection, using concept mapping and thematic analysis.

RESULTS

Among 1,722 patient episodes, physicians rejected recommendations to send a patient home in 24%, leaving text in 53%; reasons for rejection of the recommendations included additional or alternative diagnoses beyond pneumonia, and comorbidities or signs of physiologic derangement contributing to risk of outpatient failure that were not processed by the CDS. Physicians rejected broad-spectrum antibiotic recommendations in 10%, leaving text in 76%; differences in pathogen risk assessment, additional patient information, concern about antibiotic properties, and admitting physician preferences were given as reasons for rejection.

CONCLUSION

While adoption of CDS recommendations for pneumonia was high, physicians rejecting recommendations frequently provided feedback, reporting alternative diagnoses, additional individual patient characteristics, and provider preferences as major reasons for rejection. CDS that collects user feedback is feasible and can contribute to a learning health system.

Prescribing trends and revisit rates following a pharmacist-driven protocol change for community-acquired pneumonia in an emergency department

OBJECTIVE

To compare pharmacist-led prescribing changes and associated 30-day revisit rates across different regimens for patients discharged from an emergency department (ED) with a diagnosis of community-acquired pneumonia (CAP).

METHODS

An observational, retrospective cohort analysis was conducted of patients who were discharged from an ED over a 4-year period with a diagnosis of CAP. Patient demographics, clinical characteristics, antibiotic selection and comorbidity and condition severity scores were collected for two cohorts: 2012-13 (before protocol change) and 2014-15 (post-protocol change). During January 2014, a pharmacist-led protocol change with prescriber education was implemented to better align ED treatment practices with clinical practice guidelines. The primary endpoint was the change in prescribing practices across the two cohorts.

KEY FINDINGS

A total of 741 patients with CAP were identified, including 411 (55.5%) patients in 2012-13 and 330 (44.5%) in 2014-15. Prescribing of macrolide monotherapy regimens decreased significantly following protocol change (70.1% versus 42.7%; difference: 27.4%, 95% CI: 23.8-31.0%) with a reciprocal increase in macrolide/β-lactam combination prescribing (6.3-21.8%; difference: 15.5%, 95% CI: 12.9-18.1%). A total of 12.2% of patients who received macrolide/β-lactam combination treatment revisited a network ED within 30 days due to worsening pneumonia, compared to 8.6% of patients who received macrolide monotherapy treatment (P = NS).

CONCLUSIONS

The current study showed a significant increase in antibiotic prescribing compliance following a pharmacist-driven protocol change and education, but no statistical difference in rates of return for macrolide monotherapy versus other regimens.

Associations between biomarkers at discharge and co-morbidities and risk of readmission after community-acquired pneumonia: a retrospective cohort study

To investigate whether hemoglobin, white blood cell count (WBC), urea, sodium, albumin, and C-reactive protein at discharge in patients hospitalized for community-acquired pneumonia (CAP) are associated with 30-day readmission. This study is a retrospective cohort study, which included all adult patients discharged after hospitalization for CAP from three Danish hospitals between January 2011 and July 2012. The outcome was all-cause, unplanned, 30-day readmission. Biomarker concentrations at discharge were transformed into binary variables by using either upper or lower quartiles as cut-off; the upper quartile was used for WBC, urea, and C-reactive protein, and the lower quartile was used for hemoglobin, sodium, and albumin. The study population consisted of 1149 patients. One hundred eighty-four (16.0%) patients were readmitted. Independent risk factors of readmission were WBC ≥ 10.6 cells × 10⁹/L (hazard ratio 1.50; 95% CI, 1.07–2.11) and albumin <32 g/L (hazard ratio 1.78; 95% CI, 1.24–2.54) at discharge and the presence of ≥ 2 co-morbidities (hazard ratio 1.74; 95% CI, 1.15–2.64). When WBC, albumin, and co-morbidities were combined into a risk-stratification tool, there was a step-wise increase in risk of readmission for patients with 1, 2, or 3 risk factors with hazard ratios of 1.76 (95% CI, 1.25–2.49), 2.59 (95% CI, 1.71–3.93), and 6.15 (95% CI 3.33–11.38), respectively. WBC ≥ 10.6 cells × 10⁹/L and albumin < 32 g/L at discharge and the presence of ≥ 2 co-morbidities were independently associated with increased risk of 30-day readmission.

Predicting the Risk of Readmission in Pneumonia. A Systematic Review of Model Performance

RATIONALE

Predicting which patients are at highest risk for readmission after hospitalization for pneumonia could enable hospitals to proactively reallocate scarce resources to reduce 30-day readmissions.

OBJECTIVES

To synthesize the available literature on readmission risk prediction models for adults who are hospitalized because of pneumonia and describe their performance.

METHODS

We systematically searched Ovid MEDLINE, Embase, The Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature databases from inception through July 2015. We included studies of adults discharged with pneumonia that developed or validated a model that predicted hospital readmission. Two independent reviewers abstracted data and assessed the risk of bias.

MEASUREMENTS AND MAIN RESULTS

Of 992 citations reviewed, 7 studies met inclusion criteria, which included 11 unique risk prediction models. All-cause 30-day readmission rates ranged from 11.8 to 20.8% (median, 17.3%). Model discrimination (C statistic) ranged from 0.59 to 0.77 (median, 0.63) with the highest-quality, best-validated model, the Centers for Medicare and Medicaid Services Pneumonia Administrative Model performing modestly (C Statistic of 0.63 in 4 separate multicenter cohorts). The best performing model (C statistic of 0.77) was a single-site study that lacked internal validation. The models had adequate calibration, with patients predicted as high risk for readmission having a higher average observed readmission rate than those predicted to be low risk. None of the studies included pneumonia illness severity scores, and only one included measures of in-hospital clinical trajectory and stability on discharge, robust predictors of readmission.

CONCLUSIONS

We found a limited number of validated pneumonia-specific readmission models, and their predictive ability was modest. To improve predictive accuracy, future models should include measures of pneumonia illness severity, hospital complications, and stability on discharge.

Enablers and barriers to the use of antibiotic guidelines in the assessment and treatment of community-acquired pneumonia-A qualitative study of clinicians' perspectives

BACKGROUND

Community-acquired pneumonia (CAP) is a common condition and a number of guidelines have been developed for its assessment and treatment. Adherence to guidelines by clinicians varies and particularly the prescribing of antibiotics often remains suboptimal.

OBJECTIVE

The aim of this study was to elucidate potential barriers and enablers to the adherence to antibiotic guidelines by clinicians treating CAP in an Australian hospital.

METHODS

Semi-structured interviews were conducted with purposively recruited senior prescribers who regularly treat CAP in an Australian hospital. Thematic analysis identified a number of themes and subthemes related to their knowledge, attitudes and behaviours associated with the use of CAP guidelines.

RESULTS

Thematic saturation was reached after 10 in-depth interviews. Although similar barriers to the use of guidelines as previously described in the literature were confirmed, a number of novel, potential enablers were drawn from the interviews. Clinicians' acceptance and accessibility of guidelines emerged as enabling factors. Generally positive attitudes towards antimicrobial stewardship services invite leveraging what was described as the relationship-based and hierarchical nature of medical practice to provide personalised feedback and updates to clinicians.

CONCLUSIONS

Adding a social and personalised approach of antimicrobial stewardship to policy- and systems-based strategies may lead to incremental improvements in guideline adherent practice when assessing and treating CAP.

Aggressive Antimicrobial Initiation for Suspected Intensive Care Unit-Acquired Infection Is Associated with Decreased Long-Term Survival after Critical Illness

BACKGROUND

The long-term significance of early and prolonged antibiotic use in critically ill patients is yet to be described. Several studies suggest that antimicrobial exposure may have as yet unrecognized long-term effects on clinically meaningful outcomes. Our group previously conducted a quasi-experimental, before and after observational cohort study of hemodynamically stable surgical patients suspected of having an intensive care unit-acquired infection. This study demonstrated that aggressive initiation of antimicrobial therapy was associated with increased 30-day deaths. In a follow-up survival analysis, we hypothesized that aggressive antimicrobial treatment would not be a significant predictor of long-term death.

METHODS

Survival data for the 201 patients included in the initial study were obtained from our clinical data repository. Univariable analysis, Kaplan-Meier, and Cox proportional hazards models were used. Survival was evaluated at one and four years. Age, gender, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and co-morbidities were chosen a priori for potential inclusion in the model. Variables that met the model assumptions after testing were included in the final model.

RESULTS

Follow-up data were available for 190 patients (95 in each group) representing 94.5% of the initial cohort. Twenty-four (25.3%) patients in the aggressive group had initial APACHE II scores of less than 15 compared with 13 (13.7%) patients in the conservative group (p = 0.04). There was a trend toward higher deaths in the aggressive group at four years (41.1% vs. 30.5%; p = 0.13). Kaplan-Meier analysis demonstrated a difference in survival at one year but not at four years. The Cox proportional hazards model showed a higher long-term death for patients in the aggressive antimicrobial group at both one and four years (hazard rate: 2.26 and 1.70, respectively).

CONCLUSION

Aggressive initiation of antimicrobial therapy is independently associated with decreased long-term survival after critical illness. While further work is needed to confirm these findings, waiting for evidence of infection before initiation of antibiotic agents may be beneficial.

Predicting 30-Day Pneumonia Readmissions Using Electronic Health Record Data

BACKGROUND

Readmissions after hospitalization for pneumonia are common, but the few risk-prediction models have poor to modest predictive ability. Data routinely collected in the electronic health record (EHR) may improve prediction.

OBJECTIVE

To develop pneumonia-specific readmission risk-prediction models using EHR data from the first day and from the entire hospital stay ("full stay").

DESIGN

Observational cohort study using stepwise-backward selection and cross-validation.

SUBJECTS

Consecutive pneumonia hospitalizations from 6 diverse hospitals in north Texas from 2009-2010.

MEASURES

All-cause nonelective 30-day readmissions, ascertained from 75 regional hospitals.

RESULTS

Of 1463 patients, 13.6% were readmitted. The first-day pneumonia-specific model included sociodemographic factors, prior hospitalizations, thrombocytosis, and a modified pneumonia severity index; the full-stay model included disposition status, vital sign instabilities on discharge, and an updated pneumonia severity index calculated using values from the day of discharge as additional predictors. The full-stay pneumonia-specific model outperformed the first-day model (C statistic 0.731 vs 0.695; P = 0.02; net reclassification index = 0.08). Compared to a validated multi-condition readmission model, the Centers for Medicare and Medicaid Services pneumonia model, and 2 commonly used pneumonia severity of illness scores, the full-stay pneumonia-specific model had better discrimination (C statistic range 0.604-0.681; P < 0.01 for all comparisons), predicted a broader range of risk, and better reclassified individuals by their true risk (net reclassification index range, 0.09-0.18).

CONCLUSIONS

EHR data collected from the entire hospitalization can accurately predict readmission risk among patients hospitalized for pneumonia. This approach outperforms a first-day pneumonia-specific model, the Centers for Medicare and Medicaid Services pneumonia model, and 2 commonly used pneumonia severity of illness scores. Journal of Hospital Medicine 2017;12:209-216.

Impact of the Joint Commission Pneumonia Core Measure on Antibiotic Use and Selection for Community-Acquired Pneumonia in the Emergency Room

Background

Prior to 2012, The Joint Commission (TJC) pneumonia core measure (PN-5) required antibiotic administration for suspected community-acquired pneumonia (CAP) within 6 hours of arrival to the emergency room (ER). In 2012, TJC issued PN-6 requiring antibiotic administration within 24 hours of presentation. Though PN-6 was anticipated to reduce overuse and inappropriate antibiotic use and improve appropriate antibiotic selection, the impact of PN-5 and PN-6 on optimizing care for CAP in the ER remains unknown.

Objective

To investigate the impact of TJC pneumonia core measures on antibiotic use in the ER for suspected CAP.

Methods

In this single-center study, medical records of patients 18 years old and older diagnosed with CAP in the ER during 2011 (PN-5) and 2012 (PN-6) and admitted for 1 day or longer were reviewed. Exclusion criteria included criteria for health care–associated pneumonia. Comparisons between groups were performed using descriptive statistics and contingency table analysis with chi-square or Fisher exact tests for categorical variables and t tests for continuous variables. Statistical analyses were performed using Microsoft Excel 2010 and SAS version 9.4.

Results

Antibiotic use was comparable between PN-5 and PN-6. Approximately half of patients in each group received an appropriate empiric CAP regimen (52% vs 54%; P = .807). Among inappropriate regimens, the most common reason was use of a beta-lactam alone (69% vs 83%; P = .26). More patients had an ultimate diagnosis of CAP with PN-6 (78% vs 86%; P = .3).

Conclusion

Changes in pneumonia core measure requirements did not have a significant impact on appropriate antibiotic use in the ER.

Pneumonia Pathogen Characterization Is an Independent Determinant of Hospital Readmission

BACKGROUND

Hospital readmissions for pneumonia occur often and are difficult to predict. For fiscal year 2013, the Centers for Medicare & Medicaid Services readmission penalties have been applied to acute myocardial infarction, heart failure, and pneumonia. However, the overall impact of pneumonia pathogen characterization on hospital readmission is undefined.

METHODS

This was a retrospective 6-year cohort study (August 2007 to September 2013).

RESULTS

We evaluated 9,624 patients with a discharge diagnosis of pneumonia. Among these patients, 4,432 (46.1%) were classified as having culture-negative pneumonia, 1,940 (20.2%) as having pneumonia caused by antibiotic-susceptible bacteria, 2,991 (31.1%) as having pneumonia caused by potentially antibiotic-resistant bacteria, and 261 (2.7%) as having viral pneumonia. The 90-day hospital readmission rate for survivors (n = 7,637, 79.4%) was greatest for patients with pneumonia attributed to potentially antibiotic-resistant bacteria (11.4%) followed by viral pneumonia (8.3%), pneumonia attributed to antibiotic-susceptible bacteria (6.6%), and culture-negative pneumonia (5.8%) (P < .001). Multiple logistic regression analysis identified pneumonia attributed to potentially antibiotic-resistant bacteria to be independently associated with 90-day readmission (OR, 1.75; 95% CI, 1.56-1.97; P < .001). Other independent predictors of 90-day readmission were Charlson comorbidity score > 4, cirrhosis, and chronic kidney disease. Culture-negative pneumonia was independently associated with lower risk for 90-day readmission.

CONCLUSIONS

Readmission after hospitalization for pneumonia is relatively common and is related to pneumonia pathogen characterization. Pneumonia attributed to potentially antibiotic-resistant bacteria is associated with an increased risk for 90-day readmission, whereas culture-negative pneumonia is associated with lower risk for 90-day readmission.