Evaluation of a Bayesian hierarchical pharmacokinetic-pharmacodynamic model for predicting parasitological outcomes in Phase 2 studies of new antimalarial drugs.

The rise of multidrug-resistant malaria requires accelerated development of novel antimalarial drugs. Pharmacokinetic-pharmacodynamic (PK-PD) models relate blood antimalarial drug concentrations with the parasite-time profile to inform dosing regimens. We performed a simulation study to assess the utility of a Bayesian hierarchical mechanistic PK-PD model for predicting parasite-time profiles for a Phase 2 study of a new antimalarial drug, cipargamin. We simulated cipargamin concentration- and malaria parasite-profiles based on a Phase 2 study of eight volunteers who received cipargamin 7 days after inoculation with malaria parasites. The cipargamin profiles were generated from a two-compartment PK model and parasite profiles from a previously published biologically informed PD model. One thousand PK-PD data sets of eight patients were simulated, following the sampling intervals of the Phase 2 study. The mechanistic PK-PD model was incorporated in a Bayesian hierarchical framework, and the parameters were estimated. Population PK model parameters describing absorption, distribution, and clearance were estimated with minimal bias (mean relative bias ranged from 1.7% to 8.4%). The PD model was fitted to the parasitaemia profiles in each simulated data set using the estimated PK parameters. Posterior predictive checks demonstrate that our PK-PD model adequately captures the simulated PD profiles. The bias of the estimated population average PD parameters was low-moderate in magnitude. This simulation study demonstrates the viability of our PK-PD model to predict parasitological outcomes in Phase 2 volunteer infection studies. This work will inform the dose-effect relationship of cipargamin, guiding decisions on dosing regimens to be evaluated in Phase 3 trials.

Exacerbation history and blood eosinophil count prior to diagnosis of COPD and risk of subsequent exacerbations.

BACKGROUND: Prior exacerbation history is used to guide initial maintenance therapy in chronic obstructive pulmonary disease (COPD); however, the recommendations were derived from patients already diagnosed and treated. METHOD: We assessed the rates of moderate (i.e. treated with antibiotics and/or systemic corticosteroids) and severe (i.e. hospitalised) exacerbations in the year following diagnosis in patients newly diagnosed with COPD according to their prior history of exacerbations, blood eosinophil counts (BEC) and whether maintenance therapy was started. Data were extracted from the Optimum Patient Care Research Database. RESULTS: 73 189 patients were included. 61.9% had no exacerbations prior to diagnosis, 21.5% had 1 moderate, 16.5% had ≥2 moderate, and 0.3% had ≥1 severe. 50% were started on maintenance therapy. In patients not started on maintenance therapy the rates (95% confidence intervals) of moderate exacerbations in the year after diagnosis in patients with 0, 1 moderate, ≥2 moderate, ≥1 severe prior exacerbations were 0.34 (0.33-0.35), 0.59 (0.56-0.61), 1.18 (1.14-1.23) and 1.21 (0.73-1.69) respectively. Similar results were seen in patients started on maintenance therapy. BEC did not add significantly to the prediction of future exacerbation risk. CONCLUSION: A single moderate exacerbation in the year prior to diagnosis increases the risk of subsequent exacerbations and more frequent or severe exacerbations prior to diagnosis are associated with a higher risk.

Opportunities to strengthen respiratory virus surveillance systems in Australia: lessons learned from the COVID-19 response.

Abstract: Disease surveillance data was critical in supporting public health decisions throughout the coronavirus disease 2019 (COVID-19) pandemic. At the same time, the unprecedented circumstances of the pandemic revealed many shortcomings of surveillance systems for viral respiratory pathogens. Strengthening of surveillance systems was identified as a priority for the recently established Australian Centre for Disease Control, which represents a critical opportunity to review pre-pandemic and pandemic surveillance practices, and to decide on future priorities, during both pandemic and inter-pandemic periods. On 20 October 2022, we ran a workshop with experts from the academic and government sectors who had contributed to the COVID-19 response in Australia on 'The role of surveillance in epidemic response', at the University of New South Wales, Sydney, Australia. Following the workshop, we developed five recommendations to strengthen respiratory virus surveillance systems in Australia, which we present here. Our recommendations are not intended to be exhaustive. We instead chose to focus on data types that are highly valuable yet typically overlooked by surveillance planners. Three of the recommendations focus on data collection activities that support the monitoring and prediction of disease impact and the effectiveness of interventions (what to measure) and two focus on surveillance methods and capabilities (how to measure). Implementation of our recommendations would enable more robust, timely, and impactful epidemic analysis.

Sepsis shapes the human γδ TCR repertoire in an age- and pathogen-dependent manner.

Sepsis affects 25 million children per year globally, leading to 2.9 million deaths and substantial disability in survivors. Extensive characterization of interactions between the host and bacteria in children is required to design novel preventive and therapeutic strategies tailored to this age group. Vγ9Vδ2 T cells are the first T cells generated in humans. These cells are defined by the expression of Vγ9Vδ2 T-cell receptors (TCRs, using the TRGV9 and TRDV2 gene segments), which react strongly against the prototypical bacterial phosphoantigen HMBPP. We investigated this reactivity by analyzing the TCR δ (TRD) repertoire in the blood of 76 children (0-16 years) with blood culture-proven bacterial sepsis caused by HMBPP-positive Escherichia coli or by HMBPP-negative Staphylococcus aureus or by HMBPP-negative Streptococcus pneumoniae. Strikingly, we found that S. aureus, and to a lesser extent E. coli but not S. pneumoniae, shaped the TRDV2 repertoire in young children (<2 years) but not in older children or adults. This dichotomy was due to the selective expansion of a fetal TRDV2 repertoire. Thus, young children possess fetal-derived Vγ9Vδ2 T cells that are highly responsive toward specific bacterial pathogens.

DHODH inhibition enhances the efficacy of immune checkpoint blockade by increasing cancer cell antigen presentation.

Pyrimidine nucleotide biosynthesis is a druggable metabolic dependency of cancer cells, and chemotherapy agents targeting pyrimidine metabolism are the backbone of treatment for many cancers. Dihydroorotate dehydrogenase (DHODH) is an essential enzyme in the de novo pyrimidine biosynthesis pathway that can be targeted by clinically approved inhibitors. However, despite robust preclinical anticancer efficacy, DHODH inhibitors have shown limited single-agent activity in phase 1 and 2 clinical trials. Therefore, novel combination therapy strategies are necessary to realize the potential of these drugs. To search for therapeutic vulnerabilities induced by DHODH inhibition, we examined gene expression changes in cancer cells treated with the potent and selective DHODH inhibitor brequinar (BQ). This revealed that BQ treatment causes upregulation of antigen presentation pathway genes and cell surface MHC class I expression. Mechanistic studies showed that this effect is (1) strictly dependent on pyrimidine nucleotide depletion, (2) independent of canonical antigen presentation pathway transcriptional regulators, and (3) mediated by RNA polymerase II elongation control by positive transcription elongation factor B (P-TEFb). Furthermore, BQ showed impressive single-agent efficacy in the immunocompetent B16F10 melanoma model, and combination treatment with BQ and dual immune checkpoint blockade (anti-CTLA-4 plus anti-PD-1) significantly prolonged mouse survival compared to either therapy alone. Our results have important implications for the clinical development of DHODH inhibitors and provide a rationale for combination therapy with BQ and immune checkpoint blockade.

Characterising HIV-1 transmission in Victoria, Australia: a molecular epidemiological study.

Background: In Australia the incidence of HIV has declined steadily, yet sustained reduction of HIV transmission in this setting requires improved public health responses. As enhanced public health responses and prioritisation of resources may be guided by molecular epidemiological data, here we aimed to assess the applicability of these approaches in Victoria, Australia. Methods: A comprehensive collection of HIV-1 pol sequences from individuals diagnosed with HIV in Victoria, Australia, between January 1st 2000 and December 31st 2020 were deidentified and used as the basis of our assessment. These sequences were subtyped and surveillance drug resistance mutations (SDRMs) identified, before definition of transmission groups was performed using HIV-TRACE (0.4.4). Phylodynamic methods were applied using BEAST (2.6.6), assessing effective reproductive numbers for large groups, and additional demographic data were integrated to provide a high resolution view of HIV transmission in Victoria on a decadal time scale. Findings: Based on standard settings for HIV-TRACE, 70% (2438/3507) of analysed HIV-1 pol sequences were readily assigned to a transmission group. Individuals in transmission groups were more commonly males (aOR 1.50), those born in Australia (aOR 2.13), those with probable place of acquisition as Victoria (aOR 6.73), and/or those reporting injectable drug use (aOR 2.13). SDRMs were identified in 375 patients (10.7%), with sustained transmission of these limited to a subset of smaller groups. Informative patterns of epidemic growth, stabilisation, and decline were observed; many transmission groups showed effective reproductive numbers (R e ) values reaching greater than 4.0, representing considerable epidemic growth, while others maintained low R e values. Interpretation: This study provides a high resolution view of HIV transmission in Victoria, Australia, and highlights the potential of molecular epidemiology to guide and enhance public health responses in this setting. This informs ongoing discussions with community groups on the acceptability and place of molecular epidemiological approaches in Australia. Funding: National Health and Medical Research Council, Australian Research Council.

Complex Hospital-Based Electronic Prescribing-Based Intervention to Support Antimicrobial Stewardship: Qualitative Study.

BACKGROUND: Antimicrobial resistance (AMR) represents a growing concern for public health. OBJECTIVE: We sought to explore the challenges associated with development and implementation of a complex intervention designed to improve AMS in hospitals. METHODS: We conducted a qualitative evaluation of a complex AMS intervention with educational, behavioral, and technological components in 5 wards of an English hospital. At 2 weeks and 7 weeks after initiating the intervention, we interviewed 25 users of the intervention, including senior and junior prescribers, a senior nurse, a pharmacist, and a microbiologist. Topics discussed included perceived impacts of different elements of the intervention and facilitators and barriers to effective use. Interviews were supplemented by 2 observations of ward rounds to gain insights into AMS practices. Data were audio-recorded, transcribed, and inductively and deductively analyzed thematically using NVivo12. RESULTS: Tracing the adoption and impact of the various components of the intervention was difficult, as it had been introduced into a setting with competing pressures. These particularly affected behavioral and educational components (eg, training, awareness-building activities), which were often delivered ad hoc. We found that the participatory intervention design had addressed typical use cases but had not catered for edge cases that only became visible when the intervention was delivered in real-world settings (eg, variations in prescribing workflows across different specialties and conditions). CONCLUSIONS: Effective user-focused design of complex interventions to promote AMS can support acceptance and use. However, not all requirements and potential barriers to use can be fully anticipated or tested in advance of full implementation in real-world settings.

The Asymptomatic Proportion of SARS-CoV-2 Omicron Variant Infections in Households: A Systematic Review.

Understanding the clinical spectrum of SARS-CoV-2 infection, including the asymptomatic fraction, is important as asymptomatic individuals are still able to infect other individuals and contribute to ongoing transmission. The WHO Unity Household transmission investigation (HHTI) protocol provides a platform for the prospective and systematic collection of high-quality clinical, epidemiological, serological and virological data from SARS-CoV-2 confirmed cases and their household contacts. These data can be used to understand key severity and transmissibility parameters-including the asymptomatic proportion-in relation to local epidemic context and help inform public health response. We aimed to estimate the asymptomatic proportion of SARS-CoV-2 Omicron variant infections in Unity-aligned HHTIs. We conducted a systematic review and meta-analysis in alignment with the PRISMA 2020 guidelines and registered our systematic review on PROSPERO (CRD42022378648). We searched EMBASE, Web of Science, MEDLINE and bioRxiv and medRxiv from 1 November 2021 to 22 August 2023. We identified 8368 records, of which 98 underwent full text review. We identified only three studies for data extraction, with substantial variation in study design and corresponding estimates of the asymptomatic proportion. As a result, we did not generate a pooled estimate or I2 metric. The limited number of quality studies that we identified highlights the need for improved preparedness and response capabilities to facilitate robust HHTI implementation, analysis and reporting, to better inform national, regional and global risk assessments and policymaking.

Healthcare Resource Utilization Associated with Intermittent Oral Corticosteroid Prescribing Patterns in Asthma.

Purpose: Oral corticosteroid (OCS) use for asthma is associated with considerable healthcare resource utilization (HCRU) and costs. However, no study has investigated this in relation to patterns of intermittent OCS prescription. Methods: This historical UK cohort study used primary care medical records, linked to Hospital Episode Statistics, from 2008 to 2019, of patients (≥4 years old) with asthma prescribed intermittent OCS. Patients were categorized by OCS prescribing pattern (one-off [single], less frequent [≥90-day gap] and frequent [<90-day gap]) and matched 1:1 (by sex, age and index date) with people never prescribed OCS with/without asthma. HCRU (reported as episodes, except for length of hospital stay [days] and any prescription [records]) and associated costs were compared between intermittent OCS and non-OCS cohorts, and among intermittent OCS prescribing patterns. Results: Of 149,191 eligible patients, 50.3% had one-off, 27.4% less frequent, and 22.3% frequent intermittent OCS prescribing patterns. Annualized non-respiratory HCRU rates were greater in the intermittent OCS versus non-OCS cohorts for GP visits (5.93 vs 4.70 episodes, p < 0.0001), hospital admissions (0.24 vs 0.16 episodes, p < 0.0001), and length of stay (1.87 vs 1.58 days, p < 0.0001). In the intermittent OCS cohort, rates were highest in the frequent prescribing group for GP visits (7.49 episodes; p < 0.0001 vs one-off), length of stay (2.15 days; p < 0.0001) and any prescription including OCS (25.22 prescriptions; p < 0.0001). Mean per-patient non-respiratory related and all-cause HCRU-related costs were higher with intermittent OCS than no OCS (£3902 vs £2722 and £8623 vs £4929, respectively), as were mean annualized costs (£565 vs £313 and £1526 vs £634, respectively). A dose-response relationship existed; HCRU-related costs were highest in the frequent prescribing cohort (p < 0.0001). Conclusion: Intermittent OCS use and more frequent intermittent OCS prescription patterns were associated with increased HCRU and associated costs. Improved asthma management is needed to reduce reliance on intermittent OCS in primary care.

Relationships between symptoms and lung function in asthma and/or chronic obstructive pulmonary disease in a real-life setting: the NOVEL observational longiTudinal studY.

BACKGROUND: The relationships between spirometric assessment of lung function and symptoms (including exacerbations) in patients with asthma and/or chronic obstructive pulmonary disease (COPD) in a real-life setting are uncertain. OBJECTIVES: To assess the relationships between baseline post-bronchodilator (post-BD) spirometry measures of lung function and symptoms and exacerbations in patients with a physician-assigned diagnosis of asthma and/or COPD. DESIGN: The NOVEL observational longiTudinal studY (NOVELTY) is a global, prospective, 3-year observational study. METHODS: Logistic regression analysis was used to evaluate relationships. Spirometry measures were assessed as percent predicted (%pred). Symptoms were assessed at baseline, and exacerbations were assessed at baseline and Year 1. RESULTS: A total of 11,181 patients in NOVELTY had spirometry data (asthma, n = 5903; COPD, n = 3881; asthma + COPD, n = 1397). A 10% lower post-BD %pred forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) - adjusted for age and sex - were significantly associated with dyspnea (modified Medical Research Council ⩾ grade 2), frequent breathlessness [St George's Respiratory Questionnaire (SGRQ)], frequent wheeze attacks (SGRQ), nocturnal awakening (Respiratory Symptoms Questionnaire; ⩾1 night/week), and frequent productive cough (SGRQ). Lower post-BD %pred FEV1 and, to a lesser extent, lower post-BD %pred FVC were significantly associated with ⩾1 physician-reported exacerbation at baseline or Year 1. This association was stronger in patients with COPD than in those with asthma. CONCLUSION: In a real-life setting, reduced lung function is consistently associated with symptoms in patients with asthma, COPD, or asthma + COPD. The relationship with exacerbations is stronger in COPD only than in asthma. TRAIL REGISTRATION: clinicaltrials.gov identifier: NCT02760329 (www.clinicaltrials.gov).

Relationships between symptoms and lung function in asthma and/or chronic obstructive pulmonary disease in a study performed in a real-life setting: the NOVELTY studyBackground: Asthma and chronic obstructive pulmonary disease (COPD) have many symptoms in common. To confirm diagnosis, doctors use spirometry, a test to measure the amount of air that can be breathed out from the lungs and how fast it can be blown out. The relationship between these measurements and symptoms in asthma and COPD is not well understood.Objectives: The aim of this research is to describe the characteristics, treatment, and impact of asthma and/or COPD in patients who are receiving their usual medical care.Methods: NOVELTY is a large study of around 12,000 patients across 19 countries. This analysis of NOVELTY looked at the relationships between two spirometry measurements and the symptoms of asthma and/or COPD experienced by patients. The spirometry measurements were: - forced expiratory volume in 1 second (FEV₁) ­ the amount of air that can be blown out of the lungs in 1 second- forced vital capacity (FVC) ­ the amount of air that can be forcibly breathed out from the lungs after taking the deepest breath possibleResults: The lower the FEV₁ and FVC, the more common the symptoms of breathlessness, wheeze attacks, night-time awakening, and coughing up of phlegm or mucus. These relationships were similar for FEV₁ and FVC. Lower FEV₁ was more strongly associated with worse symptoms in COPD than in asthma.Conclusion: These findings help to improve our understanding of the relationships between spirometry measures and symptoms in patients with asthma and/or COPD.

Age differentially impacts adaptive immune responses induced by adenoviral versus mRNA vaccines against COVID-19.

Adenoviral and mRNA vaccines encoding the viral spike (S) protein have been deployed globally to contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Older individuals are particularly vulnerable to severe infection, probably reflecting age-related changes in the immune system, which can also compromise vaccine efficacy. It is nonetheless unclear to what extent different vaccine platforms are impacted by immunosenescence. Here, we evaluated S protein-specific immune responses elicited by vaccination with two doses of BNT162b2 or ChAdOx1-S and subsequently boosted with a single dose of BNT162b2 or mRNA-1273, comparing age-stratified participants with no evidence of previous infection with SARS-CoV-2. We found that aging profoundly compromised S protein-specific IgG titers and further limited S protein-specific CD4+ and CD8+ T cell immunity as a probable function of progressive erosion of the naive lymphocyte pool in individuals vaccinated initially with BNT162b2. Our results demonstrate that primary vaccination with ChAdOx1-S and subsequent boosting with BNT162b2 or mRNA-1273 promotes sustained immunological memory in older adults and potentially confers optimal protection against coronavirus disease 2019.

Immunotoxin-mediated depletion of Gag-specific CD8+ T cells undermines natural control of SIV.

Antibody-mediated depletion studies have demonstrated that CD8+ T cells are required for effective immune control of SIV. However, this approach is potentially confounded by several factors, including reactive CD4+ T cell proliferation, and provides no information on epitope specificity, a likely determinant of CD8+ T cell efficacy. We circumvented these limitations by selectively depleting CD8+ T cells specific for the Gag epitope CTPYDINQM (CM9) via the administration of immunotoxin-conjugated tetrameric complexes of CM9/Mamu-A*01. Immunotoxin administration effectively depleted circulating but not tissue-localized CM9-specific CD8+ T cells, akin to the bulk depletion pattern observed with antibodies directed against CD8. However, we found no evidence to indicate that circulating CM9-specific CD8+ T cells suppressed viral replication in Mamu-A*01+ rhesus macaques during acute or chronic progressive infection with a pathogenic strain of SIV. This observation extended to macaques with established infection during and after continuous antiretroviral therapy. In contrast, natural controller macaques experienced dramatic increases in plasma viremia after immunotoxin administration, highlighting the importance of CD8+ T cell-mediated immunity against CM9. Collectively, these data showed that CM9-specific CD8+ T cells were necessary but not sufficient for robust immune control of SIV in a nonhuman primate model and, more generally, validated an approach that could inform the design of next-generation vaccines against HIV-1.

Immune imprinting in early life shapes cross-reactivity to influenza B virus haemagglutinin.

Influenza exposures early in life are believed to shape future susceptibility to influenza infections by imprinting immunological biases that affect cross-reactivity to future influenza viruses. However, direct serological evidence linked to susceptibility is limited. Here we analysed haemagglutination-inhibition titres in 1,451 cross-sectional samples collected between 1992 and 2020, from individuals born between 1917 and 2008, against influenza B virus (IBV) isolates from 1940 to 2021. We included testing of 'future' isolates that circulated after sample collection. We show that immunological biases are conferred by early life IBV infection and result in lineage-specific cross-reactivity of a birth cohort towards future IBV isolates. This translates into differential estimates of susceptibility between birth cohorts towards the B/Yamagata and B/Victoria lineages, predicting lineage-specific birth-cohort distributions of observed medically attended IBV infections. Our data suggest that immunological measurements of imprinting could be important in modelling and predicting virus epidemiology.

Budesonide/Glycopyrrolate/Formoterol for the Management of COPD in a UK Primary Care Population: Real-World Use and Early Medication Success.

Purpose: Real-life research is needed to evaluate the effectiveness of budesonide/glycopyrrolate/formoterol (BGF) in routine COPD primary care management. We assessed the frequency of medication success among patients with COPD who initiated BGF using real-world data. Patients and Methods: Patients with a recorded diagnostic COPD code who started BGF with ≥2 prescriptions within 90-days were identified in the UK Optimum Patient Care Research Database and followed from first prescription until censoring at the end of follow-up (180-days), death, leaving database or end of data at 24/10/2022. The primary outcome was medication success at 90-days post-BGF initiation, defined as no major cardiac or respiratory event (ie no complicated COPD exacerbation, hospitalization for any respiratory event, myocardial infarction, new/hospitalized heart failure, and death) and no incidence of pneumonia. Medication success was also assessed at 180-days post-BGF initiation. Overall real-life medication success was claimed if the lower 95% confidence interval (CI) for the proportion of patients meeting the primary outcome was ≥70% (defined a priori). Results: Two hundred eighty-five patients were included. Prior to BGF initiation, these patients often had severe airflow obstruction (mean ppFEV1: 54.5%), were highly symptomatic (mMRC ≥2: 77.9% (n = 205/263); mean CAT score: 21.7 (SD 7.8)), with evidence of short-acting ß2-agonist (SABA) over-use (≥3 inhalers/year: 62.1%, n=179/285), repeat OCS prescriptions (≥2 courses/year: 33.0%, n = 95/285) and multiple primary care consultations (≥2 visits/year: 61.1%, n = 174/285). Overall, 39.6% of patients (n = 113/285) switched from previous triple therapies. Real-life medication success was achieved by 96.5% of patients (n = 275/285 [95% CI: 93.6, 98.3]) during 90-days treatment with BGF and by 91.8% (n = 169/184 [95% CI: 86.9, 95.4]) of patients at 180-days. The prescribed daily dose of SABA remained stable over the study period. Conclusion: The majority of patients initiating BGF experienced real-life medication success reflecting the absence of severe cardiopulmonary events. These benefits were apparent after 90-days of treatment and sustained over 180-days.

Bisoprolol in Patients With Chronic Obstructive Pulmonary Disease at High Risk of Exacerbation: The BICS Randomized Clinical Trial.

Importance: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Observational studies report that ß-blocker use may be associated with reduced risk of COPD exacerbations. However, a recent trial reported that metoprolol did not reduce COPD exacerbations and increased COPD exacerbations requiring hospital admission. Objective: To test whether bisoprolol decreased COPD exacerbations in people with COPD at high risk of exacerbations. Design, Setting, and Participants: The Bisoprolol in COPD Study (BICS) was a double-blind placebo-controlled randomized clinical trial conducted in 76 UK sites (45 primary care clinics and 31 secondary clinics). Patients with COPD who had at least moderate airflow obstruction on spirometry (ratio of forced expiratory volume in the first second of expiration [FEV1] to forced vital capacity <0.7; FEV1 <80% predicted) and at least 2 COPD exacerbations treated with oral corticosteroids, antibiotics, or both in the prior 12 months were enrolled from October 17, 2018, to May 31, 2022. Follow-up concluded on April 18, 2023. Interventions: Patients were randomly assigned to bisoprolol (n = 261) or placebo (n = 258). Bisoprolol was started at 1.25 mg orally daily and was titrated as tolerated during 4 sessions to a maximum dose of 5 mg/d, using a standardized protocol. Main Outcomes and Measures: The primary clinical outcome was the number of patient-reported COPD exacerbations treated with oral corticosteroids, antibiotics, or both during the 1-year treatment period. Safety outcomes included serious adverse events and adverse reactions. Results: Although the trial planned to enroll 1574 patients, recruitment was suspended from March 16, 2020, to July 31, 2021, due to the COVID-19 pandemic. Two patients in each group were excluded postrandomization. Among the 515 patients (mean [SD] age, 68 [7.9] years; 274 men [53%]; mean FEV1, 50.1%), primary outcome data were available for 514 patients (99.8%) and 371 (72.0%) continued taking the study drug. The primary outcome of patient-reported COPD exacerbations treated with oral corticosteroids, antibiotics, or both was 526 in the bisoprolol group, with a mean exacerbation rate of 2.03/y, vs 513 exacerbations in the placebo group, with a mean exacerbation rate of 2.01/y. The adjusted incidence rate ratio was 0.97 (95% CI, 0.84-1.13; P = .72). Serious adverse events occurred in 37 of 255 patients in the bisoprolol group (14.5%) vs 36 of 251 in the placebo group (14.3%; relative risk, 1.01; 95% CI, 0.62-1.66; P = .96). Conclusions and Relevance: Among people with COPD at high risk of exacerbation, treatment with bisoprolol did not reduce the number of self-reported COPD exacerbations requiring treatment with oral corticosteroids, antibiotics, or both. Trial Registration: isrctn.org Identifier: ISRCTN10497306.

Machine Learning to Identify Clusters in Family Medicine Diplomate Motivations and Their Relationship to Continuing Certification Exam Outcomes: Findings and Potential Future Implications.

BACKGROUND: The potential for machine learning (ML) to enhance the efficiency of medical specialty boards has not been explored. We applied unsupervised ML to identify archetypes among American Board of Family Medicine (ABFM) Diplomates regarding their practice characteristics and motivations for participating in continuing certification, then examined associations between motivation patterns and key recertification outcomes. METHODS: Diplomates responding to the 2017 to 2021 ABFM Family Medicine continuing certification examination surveys selected motivations for choosing to continue certification. We used Chi-squared tests to examine difference proportions of Diplomates failing their first recertification examination attempt who endorsed different motivations for maintaining certification. Unsupervised ML techniques were applied to generate clusters of physicians with similar practice characteristics and motivations for recertifying. Controlling for physician demographic variables, we used logistic regression to examine the effect of motivation clusters on recertification examination success and validated the ML clusters by comparison with a previously created classification schema developed by experts. RESULTS: ML clusters largely recapitulated the intrinsic/extrinsic framework devised by experts previously. However, the identified clusters achieved a more equal partitioning of Diplomates into homogenous groups. In both ML and human clusters, physicians with mainly extrinsic or mixed motivations had lower rates of examination failure than those who were intrinsically motivated. DISCUSSION: This study demonstrates the feasibility of using ML to supplement and enhance human interpretation of board certification data. We discuss implications of this demonstration study for the interaction between specialty boards and physician Diplomates.

Erratum to "Learnings from the Australian first few X household transmission project for COVID-19" [The Lancet Regional Health - Western Pacific 28 (2022) 100573].

[This corrects the article DOI: 10.1016/j.lanwpc.2022.100573.].

Combination of Antistaphylococcal ß-Lactam With Standard Therapy Compared to Standard Therapy Alone for the Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia: A Post Hoc Analysis of the CAMERA2 Trial Using a Desirability of Outcome Ranking Approach.

Background: Desirability of outcome ranking (DOOR) is an emerging approach to clinical trial outcome measurement using an ordinal scale to incorporate efficacy and safety endpoints. Methods: We applied a previously validated DOOR endpoint to a cohort of CAMERA2 trial participants with methicillin-resistant Staphylococcus aureus bacteremia (MRSAB). Participants were randomly assigned to standard therapy, or to standard therapy plus an antistaphylococcal ß-lactam (combination therapy). Each participant was assigned a DOOR category, within which they were further ranked according to their hospital length of stay (LOS) and duration of intravenous antibiotic treatment. We calculated the probability and the generalized odds ratio of participants receiving combination therapy having worse outcomes than those receiving standard therapy. Results: Participants assigned combination therapy had a 54.5% (95% confidence interval [CI], 48.9%-60.1%; P = .11) probability and a 1.2-fold odds (95% CI, .95-1.50; P = .12) of having a worse outcome than participants on standard therapy. When further ranked according to LOS and duration of antibiotic treatment, participants in the combination group had a 55.6% (95% CI, 49.5%-61.7%) and 55.3% (95% CI, 49.2%-61.4%) probability of having a worse outcome than participants in the standard treatment group, respectively. Conclusions: When considering both efficacy and safety, treatment of MRSAB with a combination of standard therapy and a ß-lactam likely results in a worse clinical outcome than standard therapy. However, a small benefit of combination therapy cannot be excluded. Most likely the toxicity of combination therapy outweighed any benefit from faster clearance of bacteremia.