Factors associated with phenotypes of dyspnea in post-COVID-19 condition: a cross-sectional study.

Post-COVID-19 condition (PCC) is defined as the persistence of symptoms, like fatigue and dyspnea, at least 3 months post-COVID infection. As dyspnea is a common symptom, we attempted to further clinically phenotype those with PCC-associated dyspnea. 1642 adults (average age of 49.6y with 63% female-predominance and BMI of 31.2 kg/m2) with physician confirmed diagnosis of PCC from June 2020-April 2023 in Alberta, Canada were included. Those with dyspnea were more likely to be female (56.5%, p = 0.005) and have higher BMI (31.3 kg/m2 vs. 29.5 kg/m2; p = 0.0008), history of asthma (21.1% vs. 12.3%; p < 0.001), more persistent PCC symptoms (p = 0.0001), more functional limitations, as well as lower quality of life (p < 0.0001). Multivariable-adjusted logistic regression analysis demonstrated dyspnea was independently associated with fatigue (OR = 4.20; CI = 2.71,6.59) and inversely associated with hospitalization for COVID-19 (OR = 0.53; CI = 0.32,0.91), age (OR = 0.98 per one year of age; CI = 0.96,0.99) and 6-min-walk-distance per 10 m difference (OR = 0.98, CI = 0.96,1.0). Fatigue was a predictor of dyspnea, and was associated with milder infection, higher BMI, and reduced 6-min-walk-distance despite normal pulmonary function. Reduced TLC or DLCO was associated with more severe infection and reduced 6-min-walk-distance. Thus, we speculate there are at least two dyspnea-associated phenotypes: phenotype with pronounced fatigue (normal PFT) and phenotype with pronounced pulmonary abnormalities (abnormal PFT). Improved understanding of the dyspnea-associated phenotypes may allow for better targeted rehabilitation.

Metabolic complications in lung transplantation for cystic fibrosis - A case control study.

Background: Metabolic complications post-lung transplant are poorly understood and little is known about how these complications differ between patients with or without cystic fibrosis (pwCF and pwoCF). This study compared post-lung transplant outcomes between pwCF and pwoCF relating to survival and incidence of diabetes, dyslipidaemia, hypertension, and renal impairment. Methods: A retrospective (2004-2017) case-control study involving 90 pwCF and 90 pwoCF (age, sex and year of transplant matched) was conducted. Demographic variables, pre/post-transplant metabolic diseases, blood investigations and medications were extracted. Descriptive statistics were used to describe the cohort. Mann-Whitney U and Chi-squared tests were used to analyse morbidity and mortality data. Regression analyses were used to identity independent variables that impacted clinical outcomes. Kaplan Meier analysis with log-rank testing was used to compare survival. Results: PwCF were younger, had lower BMIs, and were less likely to have pre-transplant extracorporeal membrane oxygenation (ECMO) use. A total of 37 pwCF and 41 pwoCF died (p = 0.65) during the period of observation with no differences in survival. Adjusting for covariates of age, sex and BMI via multiple logistic regression, CF status was associated with a dramatic increased risk of new-onset diabetes post-transplant (adjusted odds ratio 28.7; 95 % CI, 28.76 to 108.7). No other differences in adjusted risk were found. Conclusions: As pwCF had a greater adjusted risk of developing new post-transplant diabetes and experienced metabolic complications at similar rates as pwoCF, the findings highlight the need for rigorous monitoring of pwCF for possible metabolic complications post-transplant.

Diverse immunological dysregulation, chronic inflammation, and impaired erythropoiesis in long COVID patients with chronic fatigue syndrome.

A substantial number of patients recovering from acute SARS-CoV-2 infection present serious lingering symptoms, often referred to as long COVID (LC). However, a subset of these patients exhibits the most debilitating symptoms characterized by ongoing myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS). We specifically identified and studied ME/CFS patients from two independent LC cohorts, at least 12 months post the onset of acute disease, and compared them to the recovered group (R). ME/CFS patients had relatively increased neutrophils and monocytes but reduced lymphocytes. Selective T cell exhaustion with reduced naïve but increased terminal effector T cells was observed in these patients. LC was associated with elevated levels of plasma pro-inflammatory cytokines, chemokines, Galectin-9 (Gal-9), and artemin (ARTN). A defined threshold of Gal-9 and ARTN concentrations had a strong association with LC. The expansion of immunosuppressive CD71+ erythroid cells (CECs) was noted. These cells may modulate the immune response and contribute to increased ARTN concentration, which correlated with pain and cognitive impairment. Serology revealed an elevation in a variety of autoantibodies in LC. Intriguingly, we found that the frequency of 2B4+CD160+ and TIM3+CD160+ CD8+ T cells completely separated LC patients from the R group. Our further analyses using a multiple regression model revealed that the elevated frequency/levels of CD4 terminal effector, ARTN, CEC, Gal-9, CD8 terminal effector, and MCP1 but lower frequency/levels of TGF-ß and MAIT cells can distinguish LC from the R group. Our findings provide a new paradigm in the pathogenesis of ME/CFS to identify strategies for its prevention and treatment.

COVID-19 Pandemic on COPD Healthcare Utilization, Exacerbations and Mortality: A Population Study.

RATIONALE: Existing work suggests that patients with COPD (pwCOPD) presented less frequently to the emergency department (ED) and were less likely to be hospitalized during the COVID-19 pandemic but it is unclear if this was due to improved health and disease management or to increased barriers/avoidance of healthcare. The objective of this study is to determine the impact of the pandemic on inpatient and outpatient healthcare utilization, disease incidence, and mortality rates in pwCOPD. METHODS: A retrospective population-based analysis using linked administrative datasets from Alberta, Canada18 months before and after March 12, 2020 was conducted to measure hospitalization, ED and outpatient visits, and COPD outpatient exacerbations during these time periods. Mortality data was also analyzed pre- versus post-pandemic, taking confirmed COVID-19 infection within 30 days into account. Subgroup analysis based on COPD exacerbation risk stratification was undertaken to determine if healthcare utilization differed based on exacerbation risk. Finally, sex-based analysis of healthcare utilization during the pandemic was also completed. RESULTS: Hospitalization/ED visits and outpatient treatment for acute exacerbations of COPD dropped while total outpatient COPD visits, including both virtual and in-person, increased during the pandemic for pwCOPD. Mortality rate increased even after adjusting for COVID-19-associated deaths. Sex-based subgroup analysis showed a greater drop in acute care utilization for females but the rise in mortality was seen for both sexes with men experiencing greater rate of mortality than women. CONCLUSIONS: Overall pwCOPD accessed acute care resources less during the pandemic which may have contributed to a rise in non-COVID all-cause mortality.

Increased frequency and mortality in persons with neurological disorders during COVID-19.

Determining the frequency and outcomes of neurological disorders associated with coronavirus disease 2019 (COVID-19) is imperative for understanding risks and for recognition of emerging neurological disorders. We investigated the susceptibility and impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among persons with premorbid neurological disorders, in addition to the post-infection incidence of neurological sequelae, in a case-control population-based cohort. Using health service data collected between 1 March 2020 and 30 June 2021, we constructed a cohort of SARS-CoV-2 RNA-positive (n = 177 892) and -negative (n = 177 800) adults who were age, sex and comorbidity matched and underwent RT-PCR testing at similar times. COVID-19-associated mortality rates were examined within the cohort. Neurological sequelae were analysed during the acute (<3 months) and the post-acute (3-9 months) phases post-infection. The risk of death was significantly greater in the SARS-CoV-2 RNA-positive (2140 per 100 000 person years) compared with RNA-negative (922 per 100 000 person years) over a follow-up of 9 months, particularly amongst those with premorbid neurological disorders: adjusted odds ratios (95% confidence interval) in persons with a prior history of parkinsonism, 1.65 (1.15-2.37); dementia, 1.30 (1.11-1.52); seizures, 1.91 (1.26-2.87); encephalopathy, 1.82 (1.02-3.23); and stroke, 1.74 (1.05-2.86). There was also a significantly increased risk for diagnosis of new neurological sequelae during the acute time phase after COVID-19, including encephalopathy, 2.0 (1.10-3.64); dementia, 1.36 (1.07-1.73); seizure, 1.77 (1.22-2.56); and brain fog, 1.96 (1.20-3.20). These risks persisted into the post-acute phase after COVID-19, during which inflammatory myopathy (2.57, 1.07-6.15) and coma (1.87, 1.22-2.87) also became significantly increased. Thus, persons with SARS-CoV-2 infection and premorbid neurological disorders are at greater risk of death, and SARS-CoV-2 infection was complicated by increased risk of new-onset neurological disorders in both the acute and post-acute phases of COVID-19.

Increased Virtual Visits to Physicians During the COVID-19 Pandemic and Estimated Impact on Physician Compensation: The Case of Lung and Colorectal Cancers, Chronic Obstructive Pulmonary Diseases, and Heart Failure in Alberta, Canada.

Introduction: The COVID-19 pandemic started in Alberta in March 2020 and significantly increased telehealth service use and provision reducing the risk of virus transmission. We examined the change in the number and proportion of virtual visits by physician specialty and condition (chronic obstructive pulmonary diseases [COPD], heart failure [HF], colorectal and lung cancers), as well as associated changes in physician compensation. Methods: A population-based design was used to analyze all processed physician claims comparing the number and proportion of virtual visits and associated physician billings relative to in-person between pre- (2019/2020) and intra-pandemic (2020/2021). Physician compensations were the claim amounts paid by the health insurance. Results: Pre-pandemic (intra-), there were 8,981 (8,897) lung cancer, 9,245 (9,029) colorectal, 37,558 (36,292) HF, and 68,270 (52,308) COPD patients. Each patient had totally 2.3-4.7 (of which 0.4-0.6% were virtual) general practitioner (GP) visits and 0.9-2.3 (0.2-0.7% were virtual) specialist visits per year pre-pandemic. The average number and proportion of per-patient virtual visits to GPs and specialists grew significantly pre- to intra-pandemic by 2,138-4,567%, and 2,201-7,104%, respectively. Given the lower fees of virtual compared with in-person visits, the reduction in physician compensation associated with the increased use of virtual care was estimated at $3.85 million, with $2.44 million attributed to specialist and $1.41 million to GP. Discussion: Utilization of telehealth increased significantly, while the physician billings per patient and physician compensation declined early in the pandemic in Alberta for the four chronic diseases considered. This study forms the basis for future study in understanding the impact of virtual care, now part of the fabric of health care delivery, on quality of care and patient safety, overall health service utilization (such as diagnostic imaging and other investigations), as well as economic impacts to patients, health care systems, and society.

"I Had to Know About It, I Had to Find It, I Had to Know How to Access it": Experiences of Access to Rehabilitation Services Among People Living with Long COVID.

Purpose: The aim of this qualitative study is to understand the need for, access to, and quality of rehabilitation services for people living with Long COVID. Little is known about the experiences of people living with Long COVID accessing rehabilitation services. Therefore, we explored health concerns leading people living with Long COVID to seek help to address functional concerns and their experiences with accessing and participating in rehabilitation. Method: Interpretive description guided exploration of participants' experiences with Long COVID rehabilitation in Alberta, Canada. Semi-structured interviews were completed with 56 participants recruited from: three publicly funded Long COVID clinics, a specialized private physiotherapy clinic, a telephone-based rehabilitation advice line, and a Workers' Compensation Board-funded Long COVID rehabilitation program. Recruitment through mass media coverage allowed us to include people who did not access rehabilitation services. Data analysis was informed by Braun and Clarke's reflexive thematic analysis. Results: Four themes were identified: (1) the burden of searching for guidance to address challenges with functioning and disability; (2) supportive relationships promote engagement in rehabilitation; (3) conditions for participation in safe rehabilitation; and (4) looking forward - provision of appropriate interventions at the right time. Conclusions: Our findings highlight the experiences of accessing rehabilitation services for people living with Long COVID. Results suggest approaches to Long COVID rehabilitation should be accessible, multi-disciplinary, flexible, and person-centred.

Objectif: étude qualitative pour comprendre les besoins en services de réadaptation des personnes qui vivent avec la COVID longue, l'accès à ces services et leur qualité. On sait peu de choses sur les expériences des personnes qui vivent avec la COVID longue et accèdent à des services de réadaptation. C'est pourquoi les auteurs ont exploré les inquiétudes qui incitent ces personnes à demander de l'aide pour répondre à leurs problèmes fonctionnels et les expériences qu'elles ont vécues en matière d'accès à la réadaptation et de participation aux services qui y sont associés. Méthodologie: exploration guidée de la description interprétative des expériences des participants qui suivent une réadaptation à cause de la COVID longue en Alberta, au Canada. Les chercheurs ont procédé à des entrevues semi-structurées auprès de 56 participants recrutés dans trois cliniques de COVID longue financées par le gouvernement, une clinique de physiothérapie spécialisée privée, une ligne téléphonique de conseils en réadaptation et un programme de réadaptation après la COVID longue remboursé par la commission des accidents de travail. Le recrutement dans les médias de masse a permis d'inclure des personnes qui n'avaient pas accédé aux services de réadaptation. L'examen des données reposait sur l'analyse thématique réflexive de Braun et Clarke. Résultats: les chercheurs ont relevé quatre thèmes : 1) le fardeau de la recherche de conseils pour répondre aux problèmes de fonctionnement et d'incapacité; 2) les relations de soutien qui favorisent la participation à la réadaptation; 3) les conditions nécessaires pour participer à une réadaptation sécuritaire et 4) pour l'avenir, la prestation d'interventions appropriées au bon moment. Conclusions: les constatations des auteurs font ressortir les expériences d'accès aux services de réadaptation chez les personnes qui vivent avec la COVID longue. Selon les résultats, les approches de réadaptation après la COVID longue devraient être accessibles, multidisciplinaires, flexibles et axées sur l'individu.

"None of us are lying": an interpretive description of the search for legitimacy and the journey to access quality health services by individuals living with Long COVID.

BACKGROUND: Understanding of Long COVID has advanced through patient-led initiatives. However, research about barriers to accessing Long COVID services is limited. This study aimed to better understand the need for, access to, and quality of, Long COVID services. We explored health needs and experiences of services, including ability of services to address needs. METHODS: Our study was informed by the Levesque et al.'s (2013) "conceptual framework of access to health care." We used Interpretive Description, a qualitative approach partly aimed at informing clinical decisions. We recruited participants across five settings. Participants engaged in one-time, semi-structured, virtual interviews. Interviews were transcribed verbatim. We used reflexive thematic analysis. Best practice to ensure methodological rigour was employed. RESULTS: Three key themes were generated from 56 interviews. The first theme illustrated the rollercoaster-like nature of participants' Long COVID symptoms and the resulting impact on function and health. The second theme highlighted participants' attempts to access Long COVID services. Guidance received from healthcare professionals and self-advocacy impacted initial access. When navigating Long COVID services within the broader system, participants encountered barriers to access around stigma; appointment logistics; testing and 'normal' results; and financial precarity and affordability of services. The third theme illuminated common factors participants liked and disliked about Long COVID services. We framed each sub-theme as the key lesson (stemming from all likes and dislikes) that, if acted upon, the health system can use to improve the quality of Long COVID services. This provides tangible ways to improve the system based directly on what we heard from participants. CONCLUSION: With Long COVID services continuously evolving, our findings can inform decision makers within the health system to better understand the lived experiences of Long COVID and tailor services and policies appropriately.

Covalent Macrocyclic Proteasome Inhibitors Mitigate Resistance in Plasmodium falciparum.

The Plasmodium proteasome is a promising antimalarial drug target due to its essential role in all parasite lifecycle stages. Furthermore, proteasome inhibitors have synergistic effects when combined with current first-line artemisinin and related analogues. Linear peptides that covalently inhibit the proteasome are effective at killing parasites and have a low propensity for inducing resistance. However, these scaffolds generally suffer from poor pharmacokinetics and bioavailability. Here we describe the development of covalent, irreversible, macrocyclic inhibitors of the Plasmodium falciparum proteasome. We identified compounds with excellent potency and low cytotoxicity; however, the first generation suffered from poor microsomal stability. Further optimization of an existing macrocyclic scaffold resulted in an irreversible covalent inhibitor carrying a vinyl sulfone electrophile that retained high potency and low cytotoxicity and had acceptable metabolic stability. Importantly, unlike the parent reversible inhibitor that selected for multiple mutations in the proteasome, with one resulting in a 5,000-fold loss of potency, the irreversible analogue only showed a 5-fold loss in potency for any single point mutation. Furthermore, an epoxyketone analogue of the same scaffold retained potency against a panel of known proteasome mutants. These results confirm that macrocycles are optimal scaffolds to target the malarial proteasome and that the use of a covalent electrophile can greatly reduce the ability of the parasite to generate drug resistance mutations.

Characterizing long-COVID brain fog: a retrospective cohort study.

BACKGROUND: Long COVID or post-COVID condition (PCC) is a common complication following acute COVID-19 infection. PCC is a multi-systems disease with neurocognitive impairment frequently reported regardless of age. Little is known about the risk factors, associated biomarkers and clinical trajectory of patients with this symptom. OBJECTIVE: To determine differences in clinical risk factors, associated biochemical markers and longitudinal clinical trajectories between patients with PCC with subjective neurocognitive symptoms (NC+) or without (NC-). METHODS: A retrospective longitudinal cohort study was performed using a well-characterized provincial database of patients with clinically confirmed PCC separated into NC+ and NC- cohorts. Demographical, clinical and biochemical differences at initial consultation between the two patient cohorts were analyzed in cross-section. Multivariate regression analyses were conducted to identify independent risk factors for neurocognitive impairment. Determination of the recovery trajectory was performed using serial assessments of the patient-reported health-related quality of life (HR-QoL) metric Eq-5D-5L-vas score. FINDINGS: Women, milder acute infection and pre-existing mental health diagnoses were independently associated with subjective neurocognitive impairment at 8 months post-infection. NC + patients demonstrated lower levels of IgG, IgG1 and IgG3 compared to NC- patients. The NC + cohort had poorer HR-QoL at initial consultation 8 months post-infection with gradual improvement over 20 months post-infection. CONCLUSIONS: Neurocognitive impairment represents a severe phenotype of PCC, associated with unique risk factors, aberrancy in immune response and a delayed recovery trajectory. Those with risk factors for neurocognitive impairment can be identified early in the disease trajectory for more intense medical follow-up.

Microbiology sampling in non-cystic fibrosis bronchiectasis cases from northern Alberta.

Non-cystic fibrosis bronchiectasis (NCFB) is a chronic respiratory disease resulting in chronic cough, thick sputum, and lower airway microbial colonization, akin to patients with cystic fibrosis (CF). NCFB is a common, yet under recognized entity which inflicts significant morbidity and mortality particularly to older individuals, with a rising prevalence in the developed world. Given that sputum cultures are a non-invasive method to characterize the lower airway microbiota in NCFB patients, for which pathogenic organisms are associated with worsened outcomes, we sought to characterize the microbiological pattern and clinical outcomes associated with sputum culture in a cohort of NCFB patients from Western Canada. A total of 20 subjects were prospectively recruited from various bronchiectasis clinics across the Greater Edmonton area. A retrospective chart review and a symptoms questionnaire was performed, gathering information not limited to symptoms, comorbidities, exacerbations, hospitalizations, sputum production, and sputum culture results over the prior 5 years. Subjects reported frequent hospitalization alongside a significant burden of symptoms. A large majority of sputum cultures grew pathogenic organisms such as Haemophilus influenzae and Pseudomonas aeruginosa. We also note the considerable waste and inefficiency associated with sputum cultures, outlining areas for which this important diagnostic modality can be improved. Accurate characterization of the airway microbiota alongside efficient delivery of health services are key to ensuring the proper treatment of individuals with NCFB, given their high disease burden and frequent hospitalization.

Extreme Sensitivity of Fitness to Environmental Conditions: Lessons from #1BigBatch.

The phrase "survival of the fittest" has become an iconic descriptor of how natural selection works. And yet, precisely measuring fitness, even for single-celled microbial populations growing in controlled laboratory conditions, remains a challenge. While numerous methods exist to perform these measurements, including recently developed methods utilizing DNA barcodes, all methods are limited in their precision to differentiate strains with small fitness differences. In this study, we rule out some major sources of imprecision, but still find that fitness measurements vary substantially from replicate to replicate. Our data suggest that very subtle and difficult to avoid environmental differences between replicates create systematic variation across fitness measurements. We conclude by discussing how fitness measurements should be interpreted given their extreme environment dependence. This work was inspired by the scientific community who followed us and gave us tips as we live tweeted a high-replicate fitness measurement experiment at #1BigBatch.

Cardiovascular Considerations in the Management of People With Suspected Long COVID.

Approximately 15% of adult Canadians with SARS-CoV-2 infection develop lingering symptoms beyond 12 weeks after acute infection, known as post-COVID condition or long COVID. Some of the commonly reported long COVID cardiovascular symptoms include fatigue, shortness of breath, chest pain, and palpitations. Suspected long-term cardiovascular complications of SARS-CoV-2 infection might present as a constellation of symptoms that can be challenging for clinicians to diagnose and treat. When assessing patients with these symptoms, clinicians need to keep in mind myalgic encephalomyelitis/chronic fatigue syndrome, postexertional malaise and postexertional symptom exacerbation, dysautonomia with cardiac manifestations such as inappropriate sinus tachycardia, and postural orthostatic tachycardia syndrome, and occasionally mast cell activation syndrome. In this review we summarize the globally evolving evidence around management of cardiac sequelae of long COVID. In addition, we include a Canadian perspective, consisting of a panel of expert opinions from people with lived experience and experienced clinicians across Canada who have been involved in management of long COVID. The objective of this review is to offer some practical guidance to cardiologists and generalist clinicians regarding diagnostic and treatment approaches for adult patients with suspected long COVID who continue to experience unexplained cardiac symptoms.

Canadian Cystic Fibrosis-related Diabetes Clinical Practice Survey: Analysis of Current Practices and Gaps in Clinical Care.

OBJECTIVES: Our aim in this study was to identify challenges and gaps in Canadian practices in screening, diagnosis, and treatment of cystic fibrosis-related diabetes (CFRD), with the goal of informing a Canadian-specific guideline for CFRD. METHODS: We conducted an online survey of health-care professionals (97 physicians and 44 allied health professionals) who care for people living with CF (pwCF) and/or CFRD (pwCFRD). RESULTS: Most pediatric centres followed <10 pwCFRD and adult centres followed >10 pwCFRD. Children with CFRD are usually followed at a separate diabetes clinic, whereas adults with CFRD may be followed by respirologists, nurse practitioners, or endocrinologists in a CF clinic or in a separate diabetes clinic. Less than 25% of pwCF had access to an endocrinologist with a special interest or expertise in CFRD. Many centres perform screening oral glucose tolerance testing with fasting and 2-hour time points. Respondents, especially those working with adults, also indicate use of additional tests for screening not currently recommended in CFRD guidelines. Pediatric practitioners tend to only use insulin to manage CFRD, whereas adult practitioners are more likely to use repaglinide as an alternative to insulin. CONCLUSIONS: Access to specialized CFRD care may be a challenge for pwCFRD in Canada. There appears to be wide heterogeneity of CFRD care organization, screening, and treatment among health-care providers caring for pwCF and/or pwCFRD across Canada. Practitioners working with adult pwCF are less likely to adhere to current clinical practice guidelines than practitioners working with children.

The incidence, risk factors, and outcomes of symptomatic avascular necrosis of bone among Chinese pediatric patients with acute lymphoblastic leukemia.

BACKGROUND: Avascular necrosis (AVN) of bone is a debilitating complication of pediatric patients with acute lymphoblastic leukemia (ALL). While it is extensively studied and reported in Western population, studies focused on Orientals are limited. This study aims to evaluate the incidence, risk factors, and clinical outcomes of AVN among Chinese children with ALL. METHODS: This study is a retrospective, territory-wide population-based cohort study of pediatric patients with ALL enrolled on one of the three consecutive ALL study protocols (ALL-IC-BFM 2002, CCLG-ALL 2008, and CCCG-ALL 2015). RESULTS: A total of 24 out of 533 pediatric subjects with ALL (4.5%) had symptomatic AVN. Age was the single most important risk factor associated with the development of AVN. Only three patients were below age of 10 at the time of diagnosis of ALL. The incidences of AVN in patients aged above and below 10 years were 18.2% ± 3.6% and 0.8% ± 0.5%, respectively, and were significantly different (p < 0.005). Treatment protocol, immunophenotype, and gender were not predictive of AVN. Among the 24 patients, five required orthopedic interventions in view of progressive and severe disease. For subjects with hip joints involvement, follow-up assessments showed 12 of 22 hip joints had radiological progression over a median duration of 3.63 years. Seventeen of them did not have pain at the latest follow-up and among patients with pain (n = 7), five did not experience any limitation on activities of daily living while two required use of walking aids or wheelchair. CONCLUSION: The incidence of symptomatic AVN in Chinese ALL patients was comparable to other studies in Western population. Adolescent age more than 10 years old was recognized to be the most important factor for development of AVN. Significant proportion of patients had radiological progression over time with a small percentage of subjects had daily activities affected.

Prediction of extubation failure among low birthweight neonates using machine learning.

OBJECTIVE: To develop machine learning models predicting extubation failure in low birthweight neonates using large amounts of clinical data. STUDY DESIGN: Retrospective cohort study using MIMIC-III, a large single-center, open-source clinical dataset. Logistic regression and boosted-tree (XGBoost) models using demographics, medications, and vital sign and ventilatory data were developed to predict extubation failure, defined as reintubation within 7 days. RESULTS: 1348 low birthweight (≤2500 g) neonates who received mechanical ventilation within the first 7 days were included, of which 350 (26%) failed a trial of extubation. The best-performing model was a boosted-tree model incorporating demographics, vital signs, ventilator parameters, and medications (AUROC 0.82). The most important features were birthweight, last FiO2, average mean airway pressure, caffeine use, and gestational age. CONCLUSIONS: Machine learning models identified low birthweight ventilated neonates at risk for extubation failure. These models will need to be validated across multiple centers to determine generalizability of this tool.

Reliability and validity of the post COVID-19 condition stigma questionnaire: A prospective cohort study.

Background: Many of the 10-20% percent of COVID-19 survivors who develop Post COVID-19 Condition (PCC, or Long COVID) describe experiences suggestive of stigmatization, a known social determinant of health. Our objective was to develop an instrument, the Post COVID-19 Condition Stigma Questionnaire (PCCSQ), with which to quantify and characterise PCC-related stigma. Methods: We conducted a prospective cohort study to assess the reliability and validity of the PCCSQ. Patients referred to our Post COVID-19 Clinic in the Canadian City of Edmonton, Alberta between May 29, 2021 and May 24, 2022 who met inclusion criteria (attending an academic post COVID-19 clinic; age ≥18 years; persistent symptoms and impairment at ≥ 12 weeks since PCR positive acute COVID-19 infection; English-speaking; internet access; consenting) were invited to complete online questionnaires, including the PCCSQ. Analyses were conducted to estimate the instrument's reliability, construct validity, and association with relevant instruments and defined health outcomes. Findings: Of the 198 patients invited, 145 (73%) met inclusion criteria and completed usable questionnaires. Total Stigma Score (TSS) on the PCCSQ ranged from 40 to 174/200. The mean (SD) was 103.9 (31.3). Cronbach's alpha was 0.97. Test-retest reliability was 0.92. Factor analysis supported a 6-factor latent construct. Subtest reliabilities were >0.75. Individuals reporting increased TSS occurred across all demographic groups. Increased risk categories included women, white ethnicity, and limited educational opportunities. TSS was positively correlated with symptoms, depression, anxiety, loneliness, reduced self-esteem, thoughts of self-harm, post-COVID functional status, frailty, EQ5D5L score, and number of ED visits. It was negatively correlated with perceived social support, 6-min walk distance, and EQ5D5L global rating. Stigma scores were significantly increased among participants reporting employment status as disabled. Interpretation: Our findings suggested that the PCCSQ is a valid, reliable tool with which to estimate PCC-related stigma. It allows for the identification of patients reporting increased stigma and offers insights into their experiences. Funding: The Edmonton Post COVID-19 Clinic is supported by the University of Alberta and Alberta Health Services. No additional sources of funding were involved in the execution of this research study.