Anaerobic Antibiotic Coverage in Aspiration Pneumonia and the Associated Benefits and Harms: A Retrospective Cohort Study

BACKGROUND

Antibiotics with extended anaerobic coverage are used commonly to treat aspiration pneumonia, which is not recommended by current guidelines.

RESEARCH QUESTION

In patients admitted to hospital for community-acquired aspiration pneumonia, does a difference exist between antibiotic therapy with limited anaerobic coverage (LAC) vs antibiotic therapy with extended anaerobic coverage (EAC) in terms of in-hospital mortality and risk of Clostridioides difficile colitis?

STUDY DESIGN AND METHODS

We conducted a multicenter retrospective cohort study across 18 hospitals in Ontario, Canada, from January 1, 2015, to January 1, 2022. Patients were included if the physician diagnosed aspiration pneumonia and prescribed guideline-concordant first-line community-acquired pneumonia parenteral antibiotic therapy to the patient within 48 h of admission. Patients then were categorized into the LAC group if they received ceftriaxone, cefotaxime, or levofloxacin. Patients were categorized into the EAC group if they received amoxicillin-clavulanate, moxifloxacin, or any of ceftriaxone, cefotaxime, or levofloxacin in combination with clindamycin or metronidazole. The primary outcome was all-cause in-hospital mortality. Secondary outcomes included incident C difficile colitis occurring after admission. Overlap weighting of propensity scores was used to balance baseline prognostic factors.

RESULTS

The LAC and EAC groups included 2,683 and 1,316 patients, respectively. In hospital, 814 patients (30.3%) and 422 patients (32.1%) in the LAC and EAC groups died, respectively. C difficile colitis occurred in 5 or fewer patients (≤ 0.2%) and 11 to 15 patients (0.8%-1.1%) in the LAC and EAC groups, respectively. After overlap weighting of propensity scores, the adjusted risk difference of EAC minus LAC was 1.6% (95% CI, -1.7% to 4.9%) for in-hospital mortality and 1.0% (95% CI, 0.3%-1.7%) for C difficile colitis.

INTERPRETATION

Extended anaerobic coverage likely is unnecessary in aspiration pneumonia because it is associated with no additional mortality benefit, only an increased risk of C difficile colitis.

More Than a Decade Since the Latest CONSORT Non-inferiority Trials Extension: Do Infectious Diseases Trials Do Enough?

More than a decade after the Consolidated Standards of Reporting Trials group released a reporting items checklist for non-inferiority randomized controlled trials, the infectious diseases literature continues to underreport these items. Trialists, journals, and peer reviewers should redouble their efforts to ensure infectious diseases studies meet these minimum reporting standards.

Evaluating in vivo effectiveness of sotrovimab for the treatment of Omicron subvariant BA.2 versus BA.1: a multicentre, retrospective cohort study

BACKGROUND

In vitro data suggested reduced neutralizing capacity of sotrovimab, a monoclonal antibody, against Omicron BA.2 subvariant. However, limited in vivo data exist regarding clinical effectiveness of sotrovimab for coronavirus disease 2019 (COVID-19) due to Omicron BA.2.

METHODS

A multicentre, retrospective cohort study was conducted at three Canadian academic tertiary centres. Electronic medical records were reviewed for patients ≥ 18 years with mild COVID-19 (sequencing-confirmed Omicron BA.1 or BA.2) treated with sotrovimab between February 1 to April 1, 2022. Thirty-day co-primary outcomes included hospitalization due to moderate or severe COVID-19; all-cause intensive care unit (ICU) admission, and all-cause mortality. Risk differences (BA.2 minus BA.1 group) for co-primary outcomes were adjusted with propensity score matching (e.g., age, sex, vaccination, immunocompromised status).

RESULTS

Eighty-five patients were included (15 BA.2, 70 BA.1) with similar baseline characteristics between groups. Adjusted risk differences were non-statistically significant between groups for 30-day hospitalization (- 14.3%; 95% confidence interval (CI): - 32.6 to 4.0%), ICU admission (- 7.1%; 95%CI: - 20.6 to 6.3%), and mortality (- 7.1%; 95%CI: - 20.6 to 6.3%).

CONCLUSIONS

No differences were demonstrated in hospitalization, ICU admission, or mortality rates within 30 days between sotrovimab-treated patients with BA.1 versus BA.2 infection. More real-world data may be helpful to properly assess sotrovimab's effectiveness against infections due to specific emerging COVID-19 variants.

Comparative Effectiveness of First-Line and Alternative Antibiotic Regimens in Hospitalized Patients With Nonsevere Community-Acquired Pneumonia: A Multicenter Retrospective Cohort Study

BACKGROUND

There are several antibiotic regimens to treat community-acquired pneumonia (CAP).

RESEARCH QUESTION

In patients hospitalized to a non-ICU ward setting with CAP, is there a difference between first-line and alternative antibiotic regimens (β-lactam plus macrolide [BL+M], β-lactam [BL] alone, respiratory fluoroquinolone [FQ], or β-lactam plus doxycycline [BL+D]) in terms of in-hospital mortality?

STUDY DESIGN AND METHODS

This retrospective cohort study included consecutive patients admitted with CAP at 19 Canadian hospitals from 2015 to 2021. Taking a target trial approach, patients were categorized into the four antibiotic groups based on the initial antibiotic treatment within 48 h of admission. Patients with severe CAP requiring ICU admission in the first 48 h were excluded. The primary outcome was all-cause in-hospital mortality. Secondary outcome included time to being discharged alive. Propensity score and overlap weighting were used to balance covariates.

RESULTS

Of 23,512 patients, 9,340 patients (39.7%) received BL+M, 9,146 (38.9%) received BL, 4,510 (19.2%) received FQ, and 516 (2.2%) received BL+D. The number of in-hospital deaths was 703 (7.5%) for the BL+M group, 888 (9.7%) for the BL group, 302 (6.7%) for the FQ group, and 31 (6.0%) for the BL+D group. The adjusted risk difference for in-hospital mortality when compared with BL+M was 1.5% (95% CI, -0.3% to 3.3%) for BL, -0.9% (95% CI, -2.9% to 1.1%) for FQ, and -1.9% (95% CI, -4.8% to 0.9%) for BL+D. Compared with BL+M, the subdistribution hazard ratio for being discharged alive was 0.90 (95% CI, 0.84-0.96) for BL, 1.07 (95% CI, 0.99-1.16) for FQ, and 1.04 (95% CI, 0.93-1.17) for BL+D.

INTERPRETATION

BL+M, FQ, and BL+D had similar outcomes and can be considered effective regimens for nonsevere CAP. Compared with BL+M, BL was associated with longer time to discharge and the CI for mortality cannot exclude a small but clinically important increase in risk.

Methodological and Reporting Quality of Noninferiority Randomized Controlled Trials Comparing Antiretroviral Therapies: A Systematic Review

BACKGROUND

It is unclear whether the reporting quality of antiretroviral (ARV) noninferiority (NI) randomized controlled trials (RCTs) has improved since the CONSORT guideline release in 2006. The primary objective of this systematic review was assessing the methodological and reporting quality of ARV NI-RCTs. We also assessed reporting quality by funding source and publication year.

METHODS

We searched Medline, Embase, and Cochrane Central from inception to 14 November 2022. We included NI-RCTs comparing ≥2 ARV regimens used for human immunodeficiency virus treatment or prophylaxis. We used the Cochrane Risk of Bias 2.0 tool to assess risk of bias. Screening and data extraction were performed blinded and in duplicate. Descriptive statistics were used to summarize data; statistical tests were 2 sided, with significance defined as P < .05. The systematic review was prospectively registered (PROSPERO CRD42022328586), and not funded.

RESULTS

We included 160 articles reporting 171 trials. Of these articles, 101 (63.1%) did not justify the NI margin used, and 28 (17.5%) did not provide sufficient information for sample size calculation. Eighty-nine of 160 (55.6%) reported both intention-to-treat and per-protocol analyses, while 118 (73.8%) described missing data handling. Ten of 171 trials (5.9%) reported potentially misleading results. Pharmaceutical industry-funded trials were more likely to be double-blinded (28.1% vs 10.3%; P = .03) and to describe missing data handling (78.5% vs 59.0%; P = .02). The overall risk of bias was low in 96 of 160 studies (60.0%).

CONCLUSIONS

ARV NI-RCTs should improve NI margin justification, reporting of intention-to-treat and per-protocol analyses, and missing data handling to increase CONSORT adherence.

Ceftriaxone and the Risk of Ventricular Arrhythmia, Cardiac Arrest, and Death Among Patients Receiving Lansoprazole

Importance

The combination of ceftriaxone and lansoprazole has been shown to prolong the corrected QT interval on electrocardiogram. However, it is unknown whether this translates to clinically important patient outcomes.

Objective

To compare lansoprazole with another proton pump inhibitor (PPI) during ceftriaxone treatment in terms of risk for ventricular arrhythmia, cardiac arrest, and in-hospital mortality.

Design, Setting, and Participants

A retrospective cohort study including adult medical inpatients receiving ceftriaxone with lansoprazole or another PPI in 13 hospitals in Ontario, Canada, was conducted from January 1, 2015, to December 31, 2021.

Exposure

Lansoprazole during ceftriaxone treatment vs other PPIs during ceftriaxone treatment.

Main Outcomes and Measures

The primary outcome was a composite of ventricular arrhythmia or cardiac arrest that occurred after hospital admission. The secondary outcome was all-cause in-hospital mortality. Propensity-score weighting was used to adjust for covariates including hospital site, demographic characteristics, comorbidities, risk factors for ventricular arrhythmia, illness severity, admitting diagnoses, and concomitant medications.

Results

Of the 31 152 patients hospitalized on internal medicine wards who were treated with ceftriaxone while receiving a PPI, 16 135 patients (51.8%) were male, and the mean (SD) age was 71.7 (16.0) years. The study included 3747 patients in the lansoprazole group and 27 405 patients in the other PPI group. Ventricular arrhythmia or cardiac arrest occurred in 126 patients (3.4%) within the lansoprazole group and 319 patients (1.2%) within the other PPI group. In-hospital mortality occurred in 746 patients (19.9%) within the lansoprazole group and 2762 patients (10.1%) in the other PPI group. After weighting using propensity scores, the adjusted risk difference for the lansoprazole group minus other PPI group was 1.7% (95% CI, 1.1%-2.3%) for ventricular arrhythmia or cardiac arrest and 7.4% (95% CI, 6.1%-8.8%) for in-hospital mortality.

Conclusions and Relevance

The findings of this cohort study suggest that combination therapy with lansoprazole and ceftriaxone should be avoided. More studies are needed to determine whether these findings could be replicated in other populations and settings.

Guidelines for Diagnosis and Management of Infective Endocarditis in Adults: A WikiGuidelines Group Consensus Statement

Importance

Practice guidelines often provide recommendations in which the strength of the recommendation is dissociated from the quality of the evidence.

Objective

To create a clinical guideline for the diagnosis and management of adult bacterial infective endocarditis (IE) that addresses the gap between the evidence and recommendation strength.

Evidence Review

This consensus statement and systematic review applied an approach previously established by the WikiGuidelines Group to construct collaborative clinical guidelines. In April 2022 a call to new and existing members was released electronically (social media and email) for the next WikiGuidelines topic, and subsequently, topics and questions related to the diagnosis and management of adult bacterial IE were crowdsourced and prioritized by vote. For each topic, PubMed literature searches were conducted including all years and languages. Evidence was reported according to the WikiGuidelines charter: clear recommendations were established only when reproducible, prospective, controlled studies provided hypothesis-confirming evidence. In the absence of such data, clinical reviews were crafted discussing the risks and benefits of different approaches.

Findings

A total of 51 members from 10 countries reviewed 587 articles and submitted information relevant to 4 sections: establishing the diagnosis of IE (9 questions); multidisciplinary IE teams (1 question); prophylaxis (2 questions); and treatment (5 questions). Of 17 unique questions, a clear recommendation could only be provided for 1 question: 3 randomized clinical trials have established that oral transitional therapy is at least as effective as intravenous (IV)-only therapy for the treatment of IE. Clinical reviews were generated for the remaining questions.

Conclusions and Relevance

In this consensus statement that applied the WikiGuideline method for clinical guideline development, oral transitional therapy was at least as effective as IV-only therapy for the treatment of IE. Several randomized clinical trials are underway to inform other areas of practice, and further research is needed.

Comparison of Preprint Postings of Randomized Clinical Trials on COVID-19 and Corresponding Published Journal Articles: A Systematic Review

IMPORTANCE

Randomized clinical trials (RCTs) on COVID-19 are increasingly being posted as preprints before publication in a scientific, peer-reviewed journal.

OBJECTIVE

To assess time to journal publication for COVID-19 RCT preprints and to compare differences between pairs of preprints and corresponding journal articles.

EVIDENCE REVIEW

This systematic review used a meta-epidemiologic approach to conduct a literature search using the World Health Organization COVID-19 database and Embase to identify preprints published between January 1 and December 31, 2021. This review included RCTs with human participants and research questions regarding the treatment or prevention of COVID-19. For each preprint, a literature search was done to locate the corresponding journal article. Two independent reviewers read the full text, extracted data, and assessed risk of bias using the Cochrane Risk of Bias 2 tool. Time to publication was analyzed using a Cox proportional hazards regression model. Differences between preprint and journal article pairs in terms of outcomes, analyses, results, or conclusions were described. Statistical analysis was performed on October 17, 2022.

FINDINGS

This study included 152 preprints. As of October 1, 2022, 119 of 152 preprints (78.3%) had been published in journals. The median time to publication was 186 days (range, 17-407 days). In a multivariable model, larger sample size and low risk of bias were associated with journal publication. With a sample size of less than 200 as the reference, sample sizes of 201 to 1000 and greater than 1000 had hazard ratios (HRs) of 1.23 (95% CI, 0.80-1.91) and 2.19 (95% CI, 1.36-3.53) for publication, respectively. With high risk of bias as the reference, medium-risk articles with some concerns for bias had an HR of 1.77 (95% CI, 1.02-3.09); those with a low risk of bias had an HR of 3.01 (95% CI, 1.71-5.30). Of the 119 published preprints, there were differences in terms of outcomes, analyses, results, or conclusions in 65 studies (54.6%). The main conclusion in the preprint contradicted the conclusion in the journal article for 2 studies (1.7%).

CONCLUSIONS AND RELEVANCE

These findings suggest that there is a substantial time lag from preprint posting to journal publication. Preprints with smaller sample sizes and high risk of bias were less likely to be published. Finally, although differences in terms of outcomes, analyses, results, or conclusions were observed for preprint and journal article pairs in most studies, the main conclusion remained consistent for the majority of studies.

Safety Profile of Linezolid in Older Adults With Renal Impairment: A Population-Based Retrospective Cohort Study

Background

The objective of this study was to characterize the safety profile of linezolid in patients with renal impairment compared with patients without renal impairment.

Methods

A population-based retrospective cohort study using linked administrative databases included patients aged 66 years or older in Ontario, Canadawho were prescribed linezolid from 2014 to 2021. Renal impairment was defined using baseline estimated glomerular filtration rate <30 mL/min/1.73 m² or receipt of dialysis. The primary outcomes were change in platelet count and severe thrombocytopenia (platelet count <50 × 10⁹/L) within 90 days. Secondary outcomes included bleeding, neutropenia, peripheral neuropathy, optic neuropathy, acidosis, serotonin syndrome, and mortality. Inverse probability of treatment weighting on propensity score was used to balance comparison groups on baseline health.

Results

Of 625 patients, 98 (15.7%) patients had renal impairment. The mean (SD) platelet change was -88.3 (108.4) 10⁹/L in the renal impairment group and -76.5 (109.8) 10⁹/L in the no renal impairment group, with an adjusted mean difference of -29.4 (95% CI, -53.4 to -5.3; P = .0165). Severe thrombocytopenia occurred in 9.2% for the renal impairment group and 5.9% for the no renal impairment group, with an adjusted risk difference of 2.7% (95% CI, -3.1% to 8.6%; P = .3655). There were no significant differences in secondary outcomes between the 2 groups.

Conclusions

Patients with renal impairment on linezolid therapy had a larger decrease in platelet count, but their risks for severe thrombocytopenia and bleeding were not significantly different than patients without renal impairment. Linezolid is likely safe in renal impairment without dose adjustment or drug level monitoring.

Association of Linezolid With Risk of Serotonin Syndrome in Patients Receiving Antidepressants

IMPORTANCE

Linezolid has the potential to interact with some antidepressants, leading to serotonin syndrome. However, few empirical data support warnings for patients taking antidepressants to avoid linezolid.

OBJECTIVES

To examine the incidence of serotonin syndrome in patients receiving oral linezolid and how concomitant antidepressant treatment changes this risk.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, retrospective cohort study used linked administrative databases at ICES to collect data from outpatients 66 years or older in Ontario, Canada, who were prescribed oral linezolid for any duration from October 1, 2014, to January 1, 2021, with follow-up to 30 days (January 31, 2021).

EXPOSURES

The use of antidepressants while receiving linezolid therapy vs no antidepressant use while receiving linezolid therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was clinically significant serotonin syndrome based on a physician diagnosis, Sternbach criteria, or the Hunter Serotonin Toxicity Criteria within 30 days of starting oral linezolid treatment. Secondary outcomes were altered mental status, hospitalization, or death within 30 days of starting linezolid treatment.

RESULTS

The study included 1134 patients (age ranges, 66-69 years for 225 patients [19.8%], 70-79 years for 473 patients [41.7%], and ≥80 years for 436 patients [38.4%]; 595 [52.5%] male) who were prescribed linezolid. Of 1134 patients, 215 (19.0%) were also taking antidepressants. Serotonin syndrome occurred in fewer than 6 patients (<0.5%). The number of serotonin syndrome cases were fewer in the antidepressant group. In a propensity score-matched cohort, the adjusted risk difference for serotonin syndrome between the antidepressant group and the no antidepressant group was -1.2% (95% CI, -2.9% to 0.5%). There were similar rates of altered mental status, hospitalization, and death between the propensity score-matched groups.

CONCLUSIONS AND RELEVANCE

In this cohort study of older patients who were prescribed linezolid, serotonin syndrome occurred rarely. Concurrent antidepressants did not significantly increase the risk of serotonin syndrome. These findings suggested that linezolid is likely safe for patients receiving antidepressants. Nevertheless, prescribers should remain vigilant for this potential drug interaction.

Staphylococcus aureus bacteremia mortality across country income groups: A secondary analysis of a systematic review

OBJECTIVES

Staphylococcus aureus bacteremia (SAB) is a common infection worldwide. We compared SAB mortality in low- and middle-income countries (LMIC) versus high-income countries (HIC) in a meta-analysis.

METHODS

We searched MEDLINE, Embase, and Cochrane Database of Systematic Reviews from 1991-2021 and included observational, single-country studies on patients with positive blood cultures for S. aureus. The main outcome was the proportion of patients with SAB who died in the hospital. A generalized linear mixed random-effects model was used to pool estimates, and a meta-regression was used to adjust for study-level characteristics.

RESULTS

A total of 332 studies involving 517,671 patients in 39 countries were included. No study was conducted in a low-income country. Only 33 (10%) studies were performed in middle-income countries (MIC), which described 6,216 patients. The pooled in-hospital mortality was 32.4% (95% confidence interval [CI] 27.2%-38.2%, T2 = 0.3063) in MIC and 22.3% (95% CI 20.1%-24.6%, T2 = 0.3257) in HIC. In a meta-regression model, MIC had higher in-hospital mortality (adjusted odds ratio 1.37, 95% CI 1.11-1.71; P = 0.0042) than HIC.

CONCLUSION

In SAB studies, LMIC are poorly represented. In-hospital mortality was significantly higher in MIC than in HIC. Research should be conducted in LMIC to characterize differences in care processes driving the mortality gap.

What Is the Optimal Follow-up Length for Mortality in Staphylococcus aureus Bacteremia? Observations From a Systematic Review of Attributable Mortality

Background

Deaths following Staphylococcus aureus bacteremia (SAB) may be related or unrelated to the infection. In SAB therapeutics research, the length of follow-up should be optimized to capture most attributable deaths and minimize nonattributable deaths. We performed a secondary analysis of a systematic review to describe attributable mortality in SAB over time.

Methods

We systematically searched Medline, Embase, and Cochrane Database of Systematic Reviews from 1 January 1991 to 7 May 2021 for human observational studies of SAB. To be included in this secondary analysis, the study must have reported attributable mortality. Two reviewers extracted study data and assessed risk of bias independently. Pooling of study estimates was not performed due to heterogeneity in the definition of attributable deaths.

Results

Twenty-four observational cohort studies were included. The median proportion of all-cause deaths that were attributable to SAB was 77% (interquartile range [IQR], 72%–89%) at 1 month and 62% (IQR, 58%–75%) at 3 months. At 1 year, this proportion was 57% in 1 study. In 2 studies that described the rate of increase in mortality over time, 2-week follow-up captured 68 of 79 (86%) and 48 of 57 (84%) attributable deaths that occurred by 3 months. By comparison, 1-month follow-up captured 54 of 57 (95%) and 56 of 60 (93%) attributable deaths that occurred by 3 months in 2 studies.

Conclusions

The proportion of deaths that are attributable to SAB decreases as follow-up lengthens. Follow-up duration between 1 and 3 months seems optimal if evaluating processes of care that impact SAB mortality.

Clinical Trials Registration

PROSPERO CRD42021253891.

Staphylococcus aureus bacteremia mortality: A systematic review and meta-analysis

BACKGROUND

Precise estimates of mortality in Staphylococcus aureus bacteremia (SAB) are important to convey prognosis and guide design of interventional studies.

OBJECTIVE

We performed a systematic review and meta-analysis to estimate the all-cause mortality in SAB and to explore how it changed with time.

DATA SOURCES

MEDLINE, Embase, and Cochrane Database of Systematic Reviews from January 1, 1991 to May 7, 2021.

STUDY ELIGIBILITY CRITERIA

Human observational studies on patients with S. aureus bloodstream infection.

PARTICIPANTS

Patients with a positive blood culture for S. aureus.

METHODS

Two independent reviewers extracted study data and assessed risk of bias using the Newcastle Ottawa Scale. A generalized linear mixed random effects model was used to pool estimates.

RESULTS

A total of 341 studies were included, which described 536,791 patients. From 2011 onwards, the estimated mortality was 10.4% (95% confidence interval (CI) 9.0%-12.1%) at 7 days, 13.3% (95% CI 11.1%-15.8%) at 2 weeks, 18.1% (95% CI 16.3%-20.0%) at 1 month, 27.0% (95% CI 21.5%-33.3%) at 3 months, and 30.2% (95% CI 22.4%-39.3%) at 1 year. In a meta-regression model of 1-month mortality, methicillin-resistant S. aureus (MRSA) had a higher mortality (adjusted odds ratio (aOR) 1.04 95% CI 1.02-1.06 per 10% increase in MRSA proportion), and compared to prior to 2001, more recent time periods had lower mortality (aORs 0.88 [95% CI 0.75-1.03] for 2001 to 2010; 0.82 [95% CI 0.69-0.97] for 2011 onwards).

CONCLUSIONS

SAB mortality has decreased over the last 3 decades. However, more than 1 in 4 patients will die within 3 months and continuous improvement in care remains necessary.

REGISTRATION

PROSPERO CRD42021253891.

How generalizable are randomized controlled trials (RCTs) in Staphylococcus aureus bacteremia? A description of the mortality gap between RCTs and observational studies

In Staphylococcus aureus bacteremia, mortality rates in randomized controlled trials (RCTs) are consistently lower than observational studies. Stringent eligibility criteria and omission of early deaths in RCTs contribute to this mortality gap. Clinicians should acknowledge the possibility of a lower treatment effect when applying RCT results to bedside care.

Bedspacing and clinical outcomes in general internal medicine: A retrospective, multicenter cohort study

BACKGROUND

Admitting hospitalized patients to off-service wards ("bedspacing") is common and may affect quality of care and patient outcomes.

OBJECTIVE

To compare in-hospital mortality, 30-day readmission to general internal medicine (GIM), and hospital length-of-stay among GIM patients admitted to GIM wards or bedspaced to off-service wards.

DESIGN, PARTICIPANTS, AND MEASURES

Retrospective cohort study including all emergency department admissions to GIM between 2015 and 2017 at six hospitals in Ontario, Canada. We compared patients admitted to GIM wards with those who were bedspaced, using multivariable regression models and propensity score matching to control for patient and situational factors.

KEY RESULTS

Among 40,440 GIM admissions, 10,745 (26.6%) were bedspaced to non-GIM wards and 29,695 (73.4%) were assigned to GIM wards. After multivariable adjustment, bedspacing was associated with no significant difference in mortality (adjusted hazard ratio 0.95, 95% confidence interval [CI]: 0.86-1.05, p = .304), slightly shorter median hospital length-of-stay (-0.10 days, 95% CI:-0.20 to -0.001, p = .047) and lower 30-day readmission to GIM (adjusted OR 0.89, 95% CI: 0.83-0.95, p = .001). Results were consistent when examining each hospital individually and outcomes did not significantly differ between medical or surgical off-service wards. Sensitivity analyses focused on the highest risk patients did not exclude the possibility of harm associated with bedspacing, although adverse outcomes were not significantly greater.

CONCLUSIONS

Overall, bedspacing was associated with no significant difference in mortality, slightly shorter hospital length-of-stay, and fewer 30-day readmissions to GIM, although potential harms in high-risk patients remain uncertain. Given that hospital capacity issues are likely to persist, future research should aim to understand how bedspacing can be achieved safely at all hospitals, perhaps by strengthening the selection of low-risk patients.

Confidence interval of risk difference by different statistical methods and its impact on the study conclusion in antibiotic non-inferiority trials

Background

Numerous statistical methods can be used to calculate the confidence interval (CI) of risk differences. There is consensus in previous literature that the Wald method should be discouraged. We compared five statistical methods for estimating the CI of risk difference in terms of CI width and study conclusion in antibiotic non-inferiority trials.

Methods

In a secondary analysis of a systematic review, we included non-inferiority trials that compared different antibiotic regimens, reported risk differences for the primary outcome, and described the number of successes and/or failures as well as patients in each arm. For each study, we re-calculated the risk difference CI using the Wald, Agresti-Caffo, Newcombe, Miettinen-Nurminen, and skewness-corrected asymptotic score (SCAS) methods. The CIs by different statistical methods were compared in terms of CI width and conclusion on non-inferiority. A wider CI was considered to be more conservative.

Results

The analysis included 224 comparisons from 213 studies. The statistical method used to calculate CI was not reported in 134 (59.8%) cases. The median (interquartile range IQR) for CI width by Wald, Agresti-Caffo, Newcombe, Miettinen-Nurminen, and SCAS methods was 13.0% (10.8%, 17.4%), 13.3% (10.9%, 18.5%), 13.6% (11.1%, 18.9%), 13.6% (11.1% and 19.0%), and 13.4% (11.1%, 18.9%), respectively. In 216 comparisons that reported a non-inferiority margin, the conclusion on non-inferiority was the same across the five statistical methods in 211 (97.7%) cases. The differences in CI width were more in trials with a sample size of 100 or less in each group and treatment success rate above 90%. Of the 18 trials in this subgroup with a specified non-inferiority margin, non-inferiority was shown in 17 (94.4%), 16 (88.9%), 14 (77.8%), 14 (77.8%), and 15 (83.3%) cases based on CI by Wald, Agresti-Caffo, Newcombe, Miettinen-Nurminen, and SCAS methods, respectively.

Conclusions

The statistical method used to calculate CI was not reported in the majority of antibiotic non-inferiority trials. Different statistical methods for CI resulted in different conclusions on non-inferiority in 2.3% cases. The differences in CI widths were highest in trials with a sample size of 100 or less in each group and a treatment success rate above 90%.

Trial registration

PROSPERO CRD42020165040. April 28, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05686-8.

Cefazolin versus cloxacillin as definitive antibiotic therapy for methicillin-susceptible Staphylococcus aureus spinal epidural abscess: a retrospective cohort study

OBJECTIVES

We compared the effectiveness of cefazolin and cloxacillin as definitive antibiotic therapy for methicillin-susceptible Staphylococcus aureus (MSSA) spinal epidural abscess (SEA).

METHODS

This retrospective cohort study included patients with MSSA SEA from two academic hospitals in Hamilton, Ontario, Canada, between 2014 and 2020. Patients treated with cefazolin were compared to those treated with cloxacillin. Co-primary outcomes included 90-day mortality, antibiotic failure, adverse reactions and recurrence. Inverse probability of treatment weighting using propensity scores was used to balance important prognostic factors and to estimate an adjusted risk difference.

RESULTS

Of 98 patients with MSSA SEA, 50 and 48 patients were treated with cefazolin and cloxacillin, respectively. Mortality at 90 days was 8% and 13% in the cefazolin and cloxacillin groups, respectively (P = 0.52). The antibiotic failure rate was 12% and 19% in the cefazolin and cloxacillin groups, respectively (P = 0.41). The serious adverse reactions rate was 0% and 4% in the cefazolin and cloxacillin groups, respectively (P = 0.24). The recurrence rate was 2% and 8% in the cefazolin and cloxacillin groups, respectively (P = 0.20). The adjusted risk difference for mortality at 90 days was -1% [95% confidence interval (CI) -10% to 8%] favouring cefazolin. The adjusted risk differences for antibiotic failure, adverse reactions and recurrence were 1% (95% CI -12% to 14%), -5% (95% CI -11% to 2%) and -18% (-36% to -1%) respectively.

CONCLUSION

Cefazolin is likely as effective as an antistaphylococcal penicillin and may be considered as a first-line treatment for MSSA SEA.

Intention-to-treat analysis may be more conservative than per protocol analysis in antibiotic non-inferiority trials: a systematic review

BACKGROUND

In non-inferiority trials, there is a concern that intention-to-treat (ITT) analysis, by including participants who did not receive the planned interventions, may bias towards making the treatment and control arms look similar and lead to mistaken claims of non-inferiority. In contrast, per protocol (PP) analysis is viewed as less likely to make this mistake and therefore preferable in non-inferiority trials. In a systematic review of antibiotic non-inferiority trials, we compared ITT and PP analyses to determine which analysis was more conservative.

METHODS

In a secondary analysis of a systematic review, we included non-inferiority trials that compared different antibiotic regimens, used absolute risk reduction (ARR) as the main outcome and reported both ITT and PP analyses. All estimates and confidence intervals (CIs) were oriented so that a negative ARR favored the control arm, and a positive ARR favored the treatment arm. We compared ITT to PP analyses results. The more conservative analysis between ITT and PP analyses was defined as the one having a more negative lower CI limit.

RESULTS

The analysis included 164 comparisons from 154 studies. In terms of the ARR, ITT analysis yielded the more conservative point estimate and lower CI limit in 83 (50.6%) and 92 (56.1%) comparisons respectively. The lower CI limits in ITT analysis favored the control arm more than in PP analysis (median of - 7.5% vs. -6.9%, p = 0.0402). CIs were slightly wider in ITT analyses than in PP analyses (median of 13.3% vs. 12.4%, p < 0.0001). The median success rate was 89% (interquartile range IQR 82 to 93%) in the PP population and 44% (IQR 23 to 60%) in the patients who were included in the ITT population but excluded from the PP population (p < 0.0001).

CONCLUSIONS

Contrary to common belief, ITT analysis was more conservative than PP analysis in the majority of antibiotic non-inferiority trials. The lower treatment success rate in the ITT analysis led to a larger variance and wider CI, resulting in a more conservative lower CI limit. ITT analysis should be mandatory and considered as either the primary or co-primary analysis for non-inferiority trials.

TRIAL REGISTRATION

PROSPERO registration number CRD42020165040 .

Local audit of empiric antibiotic therapy in bacteremia: A retrospective cohort study

Background

It is unclear if a local audit would be useful in providing guidance on how to improve local practice of empiric antibiotic therapy. We performed an audit of antibiotic therapy in bacteremia to evaluate the proportion and risk factors for inadequate empiric antibiotic coverage.

Methods

This retrospective cohort study included patients with positive blood cultures across 3 hospitals in Hamilton, Ontario, Canada during October of 2019. Antibiotic therapy was considered empiric if it was administered within 24 hours after blood culture collection. Adequate coverage was defined as when the isolate from blood culture was tested to be susceptible to the empiric antibiotic. A multivariable logistic regression model was used to predict inadequate empiric coverage. Diagnostic accuracy of a clinical pathway based on patient risk factors was compared to clinician’s decision in predicting which bacteria to empirically cover.

Results

Of 201 bacteremia cases, empiric coverage was inadequate in 56 (27.9%) cases. Risk factors for inadequate empiric coverage included unknown source at initiation of antibiotic therapy (adjusted odds ratio (aOR) of 2.76 95% CI 1.27–6.01, P = 0.010) and prior antibiotic therapy within 90 days (aOR of 2.46 95% CI 1.30–4.74, P = 0.006). A clinical pathway that considered community-associated infection as low risk for Pseudomonas was better at ruling out Pseudomonas bacteremia with a negative likelihood ratio of 0.17 (95% CI 0.03–1.10) compared to clinician’s decision with negative likelihood ratio of 0.34 (95% CI 0.10–1.22).

Conclusions

An audit of antibiotic therapy in bacteremia is feasible and may provide useful feedback on how to locally improve empiric antibiotic therapy.

Presence of urinary symptoms in bacteremic urinary tract infection: a retrospective cohort study of Escherichia coli bacteremia

Background

It is important to understand clinical features of bacteremic urinary tract infection (bUTI), because bUTI is a serious infection that requires prompt diagnosis and antibiotic therapy. Escherichia coli is the most common and important uropathogen. The objective of our study was to characterize the clinical presentation of E coli bUTI.

Methods

Retrospective cohort study of consecutive adult patients admitted for community acquired E. coli bacteremia from January 1, 2015 to December 31, 2016 was conducted at 4 acute care academic and community hospitals in Toronto, Ontario, Canada. Logistic regression models were developed to identify E coli bUTI cases without urinary symptoms.

Results

Of 462 patients with E. coli bacteremia, 284 (61.5%) patients had a urinary source. Of these 284 patients, 161 (56.7%) had urinary symptoms. In a multivariable model, bUTI without urinary symptoms were associated with older age (age < 65 years as reference, age 65–74 years had OR of 2.13 95% CI 0.99–4.59 p = 0.0523; age 75–84 years had OR of 1.80 95% CI 0.91–3.57 p = 0.0914; age > =85 years had OR of 2.95 95% CI 1.44–6.18 p = 0.0036) and delirium (OR of 2.12 95% CI 1.13–4.03 p = 0.0207). Sepsis by SIRS criteria was present in 274 (96.5%) of all bUTI cases and 119 (96.8%) of bUTI cases without urinary symptoms.

Conclusion

The majority of patients with E. coli bacteremia had a urinary source. A significant proportion of bUTI cases had no urinary symptoms elicited on history. Elderly and delirious patients were more likely to have bUTI without urinary symptoms. In elderly and delirious patients with sepsis by SIRS criteria but without a clear infectious source, clinicians should suspect, investigate, and treat for bUTI.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12879-020-05499-1.

Methodological and reporting quality of non-inferiority randomized controlled trials comparing antibiotic therapies: a systematic review

BACKGROUND

Antibiotic non-inferiority randomized controlled trials (RCTs) are used for approval of new antibiotics and making changes to antibiotic prescribing in clinical practice. We conducted a systematic review to assess the methodological and reporting quality of antibiotic non-inferiority RCTs.

METHODS

We searched MEDLINE, Embase, the Cochrane Database of Systematic Reviews and the FDA drug database from inception until Nov 22, 2019 for non-inferiority RCTs comparing different systemic antibiotic therapies. Comparisons between antibiotic types, doses, administration routes or durations were included. Methodological and reporting quality indicators were based on the CONSORT reporting guidelines. Two independent reviewers extracted the data.

RESULTS

The systematic review included 227 studies. Of these, 135 (59.5%) studies were supported by pharmaceutical industry. Only 83 (36.6%) studies provided a justification for the non-inferiority margin. Reporting of both intention-to-treat (ITT) and per-protocol (PP) analyses were done in 165 (72.7%) studies. The conclusion was misleading in 34 (15.0%) studies. The studies funded by pharmaceutical industry were less likely to be stopped early due to logistical reasons (3.0% vs. 19.1%, OR=0.13 95% CI 0.04-0.37) and to show inconclusive results (11.1% vs. 42.9%, OR=0.17 95% CI 0.08-0.33). The quality of studies decreased over time with respect to blinding, early stopping, reporting of ITT with PP analysis and having misleading conclusions.

CONCLUSIONS

There is room for improvement in the methodology and reporting of antibiotic non-inferiority trials. Quality can be improved across the entire spectrum from investigators, funding agencies, as well as during the peer-review process.

Risk factors, costs and complications of delayed hospital discharge from internal medicine wards at a Canadian academic medical centre: retrospective cohort study

Background

Hospitalized patients are designated alternate level of care (ALC) when they no longer require hospitalization but discharge is delayed while they await alternate disposition or living arrangements. We assessed hospital costs and complications for general internal medicine (GIM) inpatients who had delayed discharge. In addition, we developed a clinical prediction rule to identify patients at risk for delayed discharge.

Methods

We conducted a retrospective cohort study of consecutive GIM patients admitted between 1 January 2015 and 1 January 2016 at a large tertiary care hospital in Canada. We compared hospital costs and complications between ALC and non-ALC patients. We derived a clinical prediction rule for ALC designation using a logistic regression model and validated its diagnostic properties.

Results

Of 4311 GIM admissions, 255 (6%) patients were designated ALC. Compared to non-ALC patients, ALC patients had longer median length of stay (30.85 vs. 3.95 days p < 0.0001), higher median hospital costs ($22,459 vs. $5003 p < 0.0001) and more complications in hospital (25.5% vs. 5.3% p < 0.0001) especially nosocomial infections (14.1% vs. 1.9% p < 0.0001). Sensitivity analyses using propensity score and pair matching yielded similar results. In a derivation cohort, seven significant risk factors for ALC were identified including age > =80 years, female sex, dementia, diabetes with complications as well as referrals to physiotherapy, occupational therapy and speech language pathology. A clinical prediction rule that assigned each of these predictors 1 point had likelihood ratios for ALC designation of 0.07, 0.25, 0.66, 1.48, 6.07, 17.13 and 21.85 for patients with 0, 1, 2, 3, 4, 5, and 6 points respectively in the validation cohort.

Conclusions

Delayed discharge is associated with higher hospital costs and complication rates especially nosocomial infections. A clinical prediction rule can identify patients at risk for delayed discharge.

Mortality of hospitalised internal medicine patients bedspaced to non-internal medicine inpatient units: retrospective cohort study

OBJECTIVE

To compare inhospital mortality of general internal medicine (GIM) patients bedspaced to off-service wards with GIM inpatients admitted to assigned GIM wards.

METHOD

A retrospective cohort study of consecutive GIM admissions between 1 January 2015 and 1 January 2016 was conducted at a large tertiary care hospital in Canada.Inhospital mortality was compared between patients admitted to off-service wards (bedspaced) and assigned GIM wards using a Cox proportional hazards model and a competing risk model. Sensitivity analyses included propensity score and pair matching based on GIM service team, workload, demographics, time of admission, reasons for admission and comorbidities.

RESULTS

Among 3243 consecutive GIM admissions, more than a third (1125, 35%) were bedspaced to off-service wards with the rest (2118, 65%) admitted to assigned GIM wards. In hospital, 176 (5%) patients died: 88/1125 (8%) bedspaced patients and 88/2118 (4%) assigned GIM ward patients. Compared with assigned GIM wards patients, bedspaced patients had an HR of 3.42 (95% CI 2.23 to 5.26; P<0.0001) for inhospital mortality at admission, which then decreased by HR of 0.97 (95% CI 0.94 to 0.99; P=0.0133) per day in hospital. Competing risk models and sensitivity analyses using propensity scores and pair matching yielded similar results.

CONCLUSIONS

Bedspaced patients had significantly higher inhospital mortality than patients admitted to assigned GIM wards. The risk was highest at admission and subsequently declined. The results of this single centre study may not be generalisable to other hospitals and may be influenced by residual confounding. Despite these limitations, the relationship between bedspacing and patient outcomes requires investigation at other institutions to determine if this common practice represents a modifiable patient safety indicator.

Clinical predictors and clinical prediction rules to estimate initial patient risk for infective endocarditis in Staphylococcus aureus bacteraemia: a systematic review and meta-analysis

OBJECTIVES

We conducted a meta-analysis to summarize diagnostic properties of risk factors and clinical prediction rules for diagnosing infective endocarditis (IE) in Staphylococcus aureus bacteraemia (SAB).

METHODS

We searched MEDLINE, Embase, and the Cochrane Database from inception to 6 January 2016 to identify studies evaluating risk factors and clinical prediction rules for IE in SAB patients. Pooled estimates of diagnostic properties for main risk factors were calculated using a bivariate random effects model.

RESULTS

Of 962 articles identified, 30 studies were included. These involved 16 538 SAB patients including 1572 IE cases. Risk factors with positive likelihood ratio (PLR) greater than 5 included embolic events (PLR 12.7, 95% CI 9.2-17.7), pacemakers (PLR 9.7, 95% CI 3.7-21.2), history of previous IE (PLR 8.2, 95% CI 3.1-22.0), prosthetic valves (PLR 5.7, 95% CI 3.2-9.5), and intravenous drug use (PLR 5.2, 95% CI 3.8-6.9). The only clinical factor with negative likelihood ratio (NLR) less than 0.5 was documented clearance of bacteraemia within 72 hours (NLR range 0.32-0.35). Of the nine published clinical prediction rules for ruling out IE, five had an NLR below 0.1.

CONCLUSIONS

SAB patients with high-risk features (embolic events, pacemakers, prosthetic valves, previous IE, or intravenous drug use) should undergo a trans-esophageal echocardiography (TEE) for IE. Clinical prediction rules show promise in safely ruling out endocarditis, but require validation in future studies.

Insulin pump use compared with intravenous insulin during labour and delivery: the INSPIRED observational cohort study

AIMS

To assess the safety and efficacy of pump therapy (continuous subcutaneous insulin infusion; CSII) during labour and delivery in women with Type 1 diabetes.

METHODS

A retrospective cohort study of 161 consecutive Type 1 diabetic pregnancies delivered during 2000-2010 at Mount Sinai Hospital, Toronto, Canada. Capillary blood glucose levels during labour and delivery and time in/out of target (target: 4-6 mmol/l) were compared along with neonatal outcomes for three groups: (1) women on pumps who stayed on pumps during labour (pump/pump n = 31), (2) women on pumps who switched to intravenous (IV) insulin infusion during labour (pump/IVn = 25), and (3) women on multiple daily injections who switched to IV insulin infusion during labour (MDIn = 105).

RESULTS

There were no significant differences between the mean or median glucose values during labour and delivery across all three groups, and no significant difference in time spent hypoglycaemic. However, women in the pump/pump group had significantly better glycaemic control as defined by mean glucose (5.5 vs. 6.4 mmol/l; P = 0.01), median glucose (5.4 vs. 6.3 mmol/l; P = 0.02), and more time spent in target (60.9% vs. 39.2%; P = 0.06) compared with women in the pump/IV group (after removing one outlier).

CONCLUSIONS

This study demonstrates that the continuation of CSII therapy during labour and delivery appears safe and efficacious. Moreover, women who choose to continue CSII have better glucose control during delivery than those who switch to IV insulin, suggesting that it should be standard practice to allow women the option of continuing CSII during labour and delivery.

Multicenter study of health care cost of patients admitted to hospital with Staphylococcus aureus bacteremia: Impact of length of stay and intensity of care

BACKGROUND

Methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S aureus bacteremia (SAB) have both been associated with high morbidity and mortality and heavy consumption of health care resources. We compared clinical and economic data for hospitalized cases of SAB in the context of a publicly funded health care system.

METHODS

A cost analysis was undertaken on an adult cohort of patients from 4 hospitals with SAB diagnosed within 3 days of hospitalization. Primary outcome was direct cost of inpatient care per case, determined at discharge and itemized using a standardized methodology.

RESULTS

A total of 435 patients were admitted with SAB; 58 had methicillin-resistant S aureus (MRSA). The median length of stay was similar in patients with MRSA and MSSA. There was no significant difference between the groups for mortality. Median direct medical costs of SAB were $12,078. Patients with MRSA had 1.32 times higher direct costs than MSSA. A similar estimate was derived using a propensity score approach (P = .148). Human health care resources comprised >70% of total costs per case, whereas antibiotics comprised 1%-2%.

CONCLUSION

Understanding the dynamics of resource consumption is critical to improving its efficiency and the quality of patient care. Our findings suggest that hospital length of stay and care intensity should be the major focus of any resource assessment exercise.

Comparative effectiveness of cefazolin versus cloxacillin as definitive antibiotic therapy for MSSA bacteraemia: results from a large multicentre cohort study

OBJECTIVES

We compared the effectiveness of cefazolin versus cloxacillin in the treatment of MSSA bacteraemia in terms of mortality and relapse.

METHODS

A retrospective cohort study examined consecutive patients with Staphylococcus aureus bacteraemia from six academic and community hospitals between 2007 and 2010. Patients with MSSA bacteraemia who received cefazolin or cloxacillin as the predominant definitive antibiotic therapy were included in the study. Ninety-day mortality was compared between the two groups matched by propensity scores.

RESULTS

Of 354 patients included in the study, 105 (30%) received cefazolin and 249 (70%) received cloxacillin as the definitive antibiotic therapy. In 90 days, 96 (27%) patients died: 21/105 (20%) in the cefazolin group and 75/249 (30%) in the cloxacillin group. Within 90 days, 10 patients (3%) had a relapse of S. aureus infection: 6/105 (6%) in the cefazolin group and 4/249 (2%) in the cloxacillin group. All relapses in the cefazolin group were related to a deep-seated infection. Based on the estimated propensity score, 90 patients in the cefazolin group were matched with 90 patients in the cloxacillin group. In the propensity score-matched groups, cefazolin had an HR of 0.58 (95% CI 0.31-1.08, P = 0.0846) for 90 day mortality.

CONCLUSIONS

There was no significant clinical difference between cefazolin and cloxacillin in the treatment of MSSA bacteraemia with respect to mortality. Cefazolin was associated with non-significantly more relapses compared with cloxacillin, especially in deep-seated S. aureus infections.