Impact of COVID-19-related health care disruptions on pathologic cancer staging during the first pandemic year: a retrospective cohort study from March 2018 to March 2021.

BACKGROUND: The COVID-19 pandemic has created major disruptions in cancer care, with reductions in diagnostic tests and treatments. We evaluated the impact of these health care-related changes on cancer staging by comparing cancers staged before and during the pandemic. METHODS: We performed a retrospective cohort study at London Health Sciences Centre and St. Joseph's Health Care London, London, Ontario, Canada. We evaluated all pathologically staged breast, colorectal, prostate, endometrial and lung cancers (the 5 most common cancers by site, excluding nonmelanoma skin cancer) over a 3-year period (Mar. 15, 2018-Mar. 14, 2021). The pre-COVID-19 group included procedures performed between Mar. 15, 2018, and Mar. 14, 2020, and the COVID-19 group included procedures performed between Mar. 15, 2020, and Mar. 14, 2021. The primary outcome was cancer stage group, based on the pathologic tumour, lymph node, metastasis system. We performed univariate analyses to compare demographic characteristics, pathologic features and cancer stage between the 2 groups. We performed multivariable ordinal regression analyses using the proportional odds model to evaluate the association between stage and timing of staging (before v. during the pandemic). RESULTS: There were 4055 cases across the 5 cancer sites. The average number of breast cancer staging procedures per 30 days increased during the pandemic compared to the yearly average in the pre-COVID-19 period (41.3 v. 39.6), whereas decreases were observed for endometrial cancer (15.9 v. 16.4), colorectal cancer (21.8 v. 24.3), prostate cancer (13.6 v. 18.5) and lung cancer (11.5 v. 15.9). For all cancer sites, there were no statistically significant differences in demographic characteristics, pathologic features or cancer stage between the 2 groups (p > 0.05). In multivariable regression analysis, for all cancer sites, cases staged during the pandemic were not associated with higher stage (breast: odds ratio [OR] 1.071, 95% confidence interval [CI] 0.826-1.388; colorectal: OR 1.201, 95% CI 0.869-1.661; endometrium: OR 0.792, 95% CI 0.495-1.252; prostate: OR 1.171, 95% CI 0.765-1.794; and lung: OR 0.826, 95% CI 0.535-1.262). INTERPRETATION: Cancer cases staged during the first year of the COVID-19 pandemic were not associated with higher stage; this likely reflects the prioritization of cancer procedures during times of reduced capacity. The impact of the pandemic period on staging procedures varied between cancer sites, which may reflect differences in clinical presentation, detection and treatment.

Temporal trends and determinants of COVID-19 vaccine series initiation after recent pregnancy.

During the rapid deployment of COVID-19 vaccines in 2021, safety concerns may have led some pregnant individuals to postpone vaccination until after giving birth. This study aimed to describe temporal patterns and factors associated with COVID-19 vaccine series initiation after recent pregnancy in Ontario, Canada. Using the provincial birth registry linked with the COVID-19 vaccine database, we identified all individuals who gave birth between January 1 and December 31, 2021, and had not yet been vaccinated by the end of pregnancy, and followed them to June 30, 2022 (follow-up ranged from 6 to 18 months). We used cumulative incidence curves to describe COVID-19 vaccine initiation after pregnancy and assessed associations with sociodemographic, pregnancy-related, and health behavioral factors using Cox proportional hazards regression to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI). Among 137,198 individuals who gave birth in 2021, 87,376 (63.7%) remained unvaccinated at the end of pregnancy; of these, 65.0% initiated COVID-19 vaccination by June 30, 2022. Lower maternal age (<25 vs. 30-34 y aHR: 0.73, 95%CI: 0.70-0.77), smoking during pregnancy (vs. nonsmoking aHR: 0.68, 95%CI: 0.65-0.72), lower neighborhood income (lowest quintile vs. highest aHR: 0.79, 95%CI: 0.76-0.83), higher material deprivation (highest quintile vs. lowest aHR: 0.74, 95%CI: 0.70-0.79), and exclusive breastfeeding (vs. other feeding aHR: 0.81, 95%CI: 0.79-0.84) were associated with lower likelihood of vaccine initiation. Among unvaccinated individuals who gave birth in 2021, COVID-19 vaccine initiation after pregnancy reached 65% by June 30, 2022, suggesting persistent issues with vaccine hesitancy and/or access to vaccination in this population.

Postmortem examination of equids >1-year-old with enterotyphlocolitis in Ontario: a retrospective descriptive study.

Equine enterotyphlocolitis is an inflammatory process of the intestinal tract of horses that is associated with multiple etiologic agents and risk factors. Most clinical cases do not have an etiologic diagnosis. We describe here the pathogens detected and the histologic lesions found in horses with enterotyphlocolitis in Ontario that were submitted for postmortem examination, 2007-2019. We reviewed the medical records of 208 horses that fulfilled inclusion criteria. Cultures were positive in 67 of 208 (32%) equids for Clostridium perfringens, in 16 of 208 (8%) for Clostridioides difficile, and in 14 of 208 (7%) for Salmonella spp.; 6 of 208 (3%) were positive for Neorickettsia risticii by PCR assay. One horse was positive in a Rhodococcus equi PCR assay. All horses tested by PCR assay for equine coronavirus and Lawsonia intracellularis were negative. The histologic lesions were characterized as follows: 6 of 208 (3%) enteritis, 5 of 208 (2%) typhlitis, 104 of 208 (50%) colitis, 37 of 208 (18%) enterocolitis, 45 of 208 (22%) typhlocolitis, and 11 of 208 (5%) enterotyphlocolitis. We strongly recommend standardized testing of diarrheic horses during and/or after postmortem examination, as well as standardized reporting of histologic lesions in enterotyphlocolitis cases.

Lessons learned from implementing a surge capacity support program for COVID-19 contact management in Ontario.

SETTING: In Ontario, local public health units (PHUs) are responsible for leading case investigations, contact tracing, and follow-up. The workforce capacity and operational requirements needed to maintain this public health strategy during the COVID-19 pandemic were unprecedented. INTERVENTION: Public Health Ontario's Contact Tracing Initiative (CTI) was established to provide a centralized workforce. This program was unique in leveraging existing human resources from federal and provincial government agencies and its targeted focus on initial and follow-up phone calls to high-risk close contacts of COVID-19 cases. By setting criteria for submissions to the program, standardizing scripts, and simplifying the data management process, the CTI was able to support a high volume of calls. OUTCOMES: During its 23 months of operation, the CTI was used by 33 of the 34 PHUs and supported over a million calls to high-risk close contacts. This initiative was able to meet its objectives while adapting to the changing dynamics of the pandemic and the implementation of a new COVID-19 provincial information system. Core strengths of the CTI were timeliness, volume, and efficient use of resources. The CTI was found to be useful for school exposures, providing support when public health measures were lifted, and in supporting PHU's reallocation of resources during the vaccine roll-out. IMPLICATIONS: When considering future use of this model, it is important to take note of the program strengths and limitations to ensure alignment with future needs for surge capacity support. Lessons learned from this initiative could provide practice-relevant knowledge for surge capacity planning.

RéSUMé: CONTEXTE: En Ontario, ce sont les bureaux de santé publique qui s'occupent des enquêtes de cas, de la recherche des contacts et des suivis. Pendant la pandémie de COVID-19, les besoins opérationnels et de capacité de la main-d'œuvre à combler pour conserver cette stratégie de santé publique ont atteint une ampleur jamais vue. INTERVENTION: L'Initiative de recherche des contacts dans le cadre de la lutte contre la COVID-19 de Santé publique Ontario a été mise sur pied dans l'objectif de centraliser l'effectif. Mobilisant des ressources humaines d'organisations fédérales et provinciales, ce programme a permis de faire les appels initiaux et de suivi aux contacts étroits de cas de COVID-19 exposés à un risque élevé. Grâce à des critères bien établis pour les soumissions au programme, à l'uniformisation des scripts et à la simplification du processus de gestion des données, un grand volume d'appels a pu être traité. RéSULTATS: Durant les 23 mois de l'Initiative, 33 des 34 bureaux de santé publique y ont eu recours. Ce sont ainsi plus d'un million d'appels à des contacts étroits qui ont pu être faits. L'Initiative a permis d'atteindre les objectifs en s'adaptant au contexte pandémique en constante évolution et de mettre en œuvre un nouveau système de gestion des renseignements provinciaux sur la COVID-19. Ses grandes forces sont la rapidité, le volume et l'efficacité de l'utilisation des ressources. Elle a été particulièrement utile dans les cas d'exposition en milieu scolaire, permettant d'offrir du soutien à la levée des mesures sanitaires et d'aider à la réaffectation des ressources des bureaux de santé publique pendant la campagne de vaccination. CONSéQUENCES: Si l'on envisage de réutiliser ce modèle, il importe de tenir compte des forces et des faiblesses du programme pour qu'il cadre avec les besoins futurs de soutien en matière de capacité de mobilisation. Les leçons tirées de cette initiative pourraient s'avérer pertinentes pour la planification de cette capacité.

SARS-CoV-2 Testing and Complications Across 6 Waves of the COVID-19 Pandemic Among Individuals Recently Experiencing Homelessness in Ontario, Canada.

This cohort study compares the rates of SARS-CoV-2 testing and complications across 6 waves of the COVID-19 pandemic in Ontario, Canada, between individuals recently experiencing homelessness, low-income residents, and the general population.

Association between the COVID-19 pandemic and first cancer treatment modality: a population-based cohort study.

BACKGROUND: Physicians were directed to prioritize using nonsurgical cancer treatment at the beginning of the COVID-19 pandemic. We sought to quantify the impact of this policy on the modality of first cancer treatment (surgery, chemotherapy, radiotherapy or no treatment). METHODS: In this population-based study using Ontario data from linked administrative databases, we identified adults diagnosed with cancer from January 2016 to November 2020 and their first cancer treatment received within 1 year postdiagnosis. Segmented Poisson regressions were applied to each modality to estimate the change in mean 1-year recipient volume per thousand patients (rate) at the start of the pandemic (the week of Mar. 15, 2020) and change in the weekly trend in rate during the pandemic (Mar. 15, 2020, to Nov. 7, 2020) relative to before the pandemic (Jan. 3, 2016, to Mar. 14, 2020). RESULTS: We included 321 535 people diagnosed with cancer. During the first week of the COVID-19 pandemic, the mean rate of receiving upfront surgery over the next year declined by 9% (rate ratio 0.91, 95% confidence interval [CI] 0.88-0.95), and chemotherapy and radiotherapy rates rose by 30% (rate ratio 1.30, 95% CI 1.23-1.36) and 13% (rate ratio 1.13, 95% CI 1.07-1.19), respectively. Subsequently, the 1-year rate of upfront surgery increased at 0.4% for each week (rate ratio 1.004, 95% CI 1.002-1.006), and chemotherapy and radiotherapy rates decreased by 0.9% (rate ratio 0.991, 95% CI 0.989-0.994) and 0.4% (rate ratio 0.996, 95% CI 0.994-0.998), respectively, per week. Rates of each modality resumed to prepandemic levels at 24-31 weeks into the pandemic. INTERPRETATION: An immediate and sustained increase in use of nonsurgical therapy as the first cancer treatment occurred during the first 8 months of the COVID-19 pandemic in Ontario. Further research is needed to understand the consequences.

A Cross-Sectional Study and Observational Assessment of Shoppers' COVID-19 Prevention Behaviors in Southwestern Ontario, Canada.

OBJECTIVE: The aim of this study was to observe the level of alcohol-based sanitizer, mask use, and physical distancing across indoor community settings in Guelph, ON, Canada, and to identify potential barriers to practicing these behaviors. METHODS: Shoppers were observed in June 2022 across 21 establishments. Discrete in-person observations were conducted and electronically recorded using smartphones. Multilevel logistic regression models were fitted to identify possible covariates for the 3 behavioral outcomes. RESULTS: Of 946 observed shoppers, 69% shopped alone, 72% had at least 1 hand occupied, 26% touched their face, 29% physically distanced ≥ 2 m, 6% used hand sanitizer, and 29% wore masks. Sanitizer use was more commonly observed among people who wore masks and in establishments with coronavirus disease (COVID-19) signage posted at the entrance. Mask use was more commonly observed during days without precipitation and in establishments with some or all touch-free entrances. Shoppers more commonly physically distanced ≥ 2 m when they were shopping alone. CONCLUSIONS: This supports evidence for environmental context influencing COVID-19 preventive behaviors. Intervention efforts aimed at visible signage, tailored messaging, and redesigning spaces to facilitate preventive behaviors may be effective at increasing adherence during outbreaks.

Association between neighbourhood composition, kindergarten educator-reported distance learning barriers, and return to school concerns during the first wave of the COVID-19 pandemic in Ontario, Canada.

Introduction: Research to date has established that the COVID-19 pandemic has not impacted everyone equitably. Whether this unequitable impact was seen educationally with regards to educator reported barriers to distance learning, concerns and mental health is less clear. Objective: The objective of this study was to explore the association between the neighbourhood composition of the school and kindergarten educator-reported barriers and concerns regarding children's learning during the first wave of COVID-19 related school closures in Ontario, Canada. Methods: In the spring of 2020, we collected data from Ontario kindergarten educators (n = 2569; 74.2% kindergarten teachers, 25.8% early childhood educators; 97.6% female) using an online survey asking them about their experiences and challenges with online learning during the first round of school closures. We linked the educator responses to 2016 Canadian Census variables based on schools' postal codes. Bivariate correlations and Poisson regression analyses were used to determine if there was an association between neighbourhood composition and educator mental health, and the number of barriers and concerns reported by kindergarten educators. Results: There were no significant findings with educator mental health and school neighbourhood characteristics. Educators who taught at schools in neighbourhoods with lower median income reported a greater number of barriers to online learning (e.g., parents/guardians not submitting assignments/providing updates on their child's learning) and concerns regarding the return to school in the fall of 2020 (e.g., students' readjustment to routines). There were no significant associations with educator reported barriers or concerns and any of the other Census neighbourhood variables (proportion of lone parent families, average household size, proportion of population that do no speak official language, proportion of population that are recent immigrants, or proportion of population ages 0-4). Conclusions: Overall, our study suggests that the neighbourhood composition of the children's school location did not exacerbate the potential negative learning experiences of kindergarten students and educators during the COVID-19 pandemic, although we did find that educators teaching in schools in lower-SES neighbourhoods reported more barriers to online learning during this time. Taken together, our study suggests that remediation efforts should be focused on individual kindergarten children and their families as opposed to school location.

Did the Long-Term Care Physician Workforce Change During the Pandemic? Describing MRP Trends in Ontario, Canada.

OBJECTIVES: To examine the practice patterns and trends of long-term care (LTC) physicians between 2019 and 2021 in Ontario, Canada. DESIGN: Population-level descriptive time trend study. SETTING AND PARTICIPANTS: Most responsible physicians (MRPs) of LTC residents of publicly funded LTC homes in Ontario, Canada, from September 2019 to December 2021. METHODS: We examined the number of MRPs in publicly regulated Ontario LTC homes before and during the COVID-19 pandemic using population-level administrative databases. Characteristics of MRPs and practice patterns were generated at baseline and across distinct time periods of the pandemic in descriptive tables. We created a Sankey diagram to visualize MRP practice changes over time. RESULTS: More than one-quarter of pre-pandemic MRPs were no longer MRPs by the end of 2021, although most continued to practice in non-LTC settings. There was a decrease from 1444 to 1266 MRPs over time. Other characteristics of MRPs remained stable over the pandemic time periods. At baseline, LTC physicians were MRP for an average of 57.3 residents. By the end of 2021, this caseload decreased to 53.3 residents per MRP. MRPs increasingly billed monthly management compensation fees over the fee-for-service model across the pandemic time periods. The number of MRPs working in an LTC home shifted to fewer MRPs per home. CONCLUSIONS AND IMPLICATIONS: MRP demographic characteristics did not change over the course of the pandemic. The observed shifts in practice patterns showed a reduction in the overall LTC MRP workforce, who delivered care to fewer residents on average in LTC homes with fewer colleagues to rely on. Future work can study how changes to LTC MRPs' practice patterns impact physician coverage, access and continuity of care, and health services and quality outcomes among residents.

Mental health and addiction health service use by physicians compared to non-physicians before and during the COVID-19 pandemic: A population-based cohort study in Ontario, Canada.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic has exacerbated mental health challenges among physicians and non-physicians. However, it is unclear if the worsening mental health among physicians is due to specific occupational stressors, reflective of general societal stressors during the pandemic, or a combination. We evaluated the difference in mental health and addictions health service use between physicians and non-physicians, before and during the COVID-19 pandemic. METHODS AND FINDINGS: We conducted a population-based cohort study in Ontario, Canada between March 11, 2017 and August 11, 2021 using data collected from Ontario's universal health system. Physicians were identified using registrations with the College of Physicians and Surgeons of Ontario between 1990 and 2020. Participants included 41,814 physicians and 12,054,070 non-physicians. We compared the first 18 months of the COVID-19 pandemic (March 11, 2020 to August 11, 2021) to the period before COVID-19 pandemic (March 11, 2017 to February 11, 2020). The primary outcome was mental health and addiction outpatient visits overall and subdivided into virtual versus in-person, psychiatrists versus family medicine and general practice clinicians. We used generalized estimating equations for the analyses. Pre-pandemic, after adjustment for age and sex, physicians had higher rates of psychiatry visits (aIRR 3.91 95% CI 3.55 to 4.30) and lower rates of family medicine visits (aIRR 0.62 95% CI 0.58 to 0.66) compared to non-physicians. During the first 18 months of the COVID-19 pandemic, the rate of outpatient mental health and addiction (MHA) visits increased by 23.2% in physicians (888.4 pre versus 1,094.7 during per 1,000 person-years, aIRR 1.39 95% CI 1.28 to 1.51) and 9.8% in non-physicians (615.5 pre versus 675.9 during per 1,000 person-years, aIRR 1.12 95% CI 1.09 to 1.14). Outpatient MHA and virtual care visits increased more among physicians than non-physicians during the first 18 months of the pandemic. Limitations include residual confounding between physician and non-physicians and challenges differentiating whether observed increases in MHA visits during the pandemic are due to stressors or changes in health care access. CONCLUSIONS: The first 18 months of the COVID-19 pandemic was associated with a larger increase in outpatient MHA visits in physicians than non-physicians. These findings suggest physicians may have had larger negative mental health during COVID-19 than the general population and highlight the need for increased access to mental health services and system level changes to promote physician wellness.

Physician benzodiazepine self-use prior to and during the COVID-19 pandemic in Ontario, Canada: a population-level cohort study.

OBJECTIVES: The aim of this study was to investigate physician benzodiazepine (BZD) self-use pre-COVID-19 pandemic and to examine changes in BZD self-use during the first year of the pandemic. DESIGN: Population-based retrospective cohort study using linked routinely collected administrative health data comparing the first year of the pandemic to the period before the pandemic. SETTING: Province of Ontario, Canada between March 2016 and March 2021. PARTICIPANTS: INTERVENTION: Onset of the COVID-19 pandemic in March 2020. OUTCOMES MEASURES: The primary outcome measure was the receipt of one or more prescriptions for BZD, which was captured via the Narcotics Monitoring System. RESULTS: In a cohort of 30 798 physicians (mean age 42, 47.8% women), we found that during the year before the pandemic, 4.4% of physicians had 1 or more BZD prescriptions. Older physicians (6.8% aged 50+ years), female physicians (5.1%) and physicians with a prior mental health (MH) diagnosis (12.4%) were more likely than younger (3.7% aged <50 years), male physicians (3.8%) and physicians without a prior MH diagnosis (2.9%) to have received 1 or more BZD prescriptions. The first year of the COVID-19 pandemic was associated with a 10.5% decrease (adjusted OR (aOR) 0.85, 95% CI: 0.80 to 0.91) in the number of physicians with 1 or more BZD prescriptions compared with the year before the pandemic. Female physicians were less likely to reduce BZD self-use (aORfemale=0.90, 95% CI: 0.83 to 0.98) compared with male physicians (aORmale=0.79, 95% CI: 0.72 to 0.87, pinteraction=0.046 during the pandemic. Physicians presenting with an incident MH visit had higher odds of filling a BZD prescription during COVID-19 compared with the prior year. CONCLUSIONS: Physicians' BZD prescriptions decreased during the first year of the COVID-19 pandemic in Ontario, Canada. These findings suggest that previously reported increases in mental distress and MH visits among physicians during the pandemic did not lead to greater self-use of BZDs.

Methodological changes implemented over time to support accurate and timely COVID-19 vaccine coverage estimates: Ontario, Canada.

The COVID-19 vaccination program implementation in Ontario, Canada has spanned multiple years and is ongoing. To meet the challenges of the program, Ontario developed and implemented a new electronic COVID-19 immunization registry, COVaxON, which captures individual-level data on all doses administered in the province enabling comprehensive coverage assessment. However, the need for ongoing COVID-19 vaccine coverage assessments over a multi-year vaccination program posed challenges necessitating methodological changes. This paper describes Ontario's COVID-19 immunization registry, the methods implemented over time to allow for the ongoing assessment of vaccine coverage by age, and the impact of those methodological changes. Throughout the course of the vaccination program, four different methodological approaches were used to calculate age-specific coverage estimates using vaccination data (numerator) obtained from COVaxON. Age-specific numerators were initially calculated using age at time of first dose (method A), but were updated to the age at coverage assessment (method B). Database enhancements allowed for the exclusion of deceased individuals from the numerator (method C). Population data (denominator) was updated to 2022 projections from the 2021 national census following their availability (method D). The impact was most evident in older age groups where vaccine uptake was high. For example, coverage estimates for individuals aged 70-79 years of age for at least one dose decreased from 104.9 % (method B) to 95.0 % (method D). Thus, methodological changes improved estimates such that none exceeded 100 %. Ontario's COVID-19 immunization registry has been transformational for vaccine program surveillance. The implementation of a single registry for COVID-19 vaccines was essential for comprehensive near real-time coverage assessment, and enabled new uses of the data to support additional components of vaccine program surveillance. The province is well positioned to build on what has been achieved as a result of the COVID-19 pandemic and expand the registry to other routine vaccination programs.

Virtual Care and Emergency Department Use During the COVID-19 Pandemic Among Patients of Family Physicians in Ontario, Canada.

Importance: The COVID-19 pandemic has played a role in increased use of virtual care in primary care. However, few studies have examined the association between virtual primary care visits and other health care use. Objective: To evaluate the association between the percentage of virtual visits in primary care and the rate of emergency department (ED) visits. Design, Setting, and Participants: This cross-sectional study used routinely collected administrative data and was conducted in Ontario, Canada. The sample comprised family physicians with at least 1 primary care visit claim between February 1 and October 31, 2021, and permanent Ontario residents who were alive as of March 31, 2021. All residents were assigned to physicians according to enrollment and billing data. Exposure: Family physicians' virtual visit rate was the exposure. Physicians were stratified by the percentage of total visits that they delivered virtually (via telephone or video) during the study period (0% [100% in person], >0%-20%, >20%-40%, >40%-60%, >60%-80%, >80% to <100%, or 100%). Main Outcomes and Measures: Population-level ED visit rate was calculated for each stratum of virtual care use. Multivariable regression models were used to understand the relative rate of patient ED use after adjusting for rurality of practice, patient characteristics, and 2019 ED visit rates. Results: Data were analyzed for a total of 13 820 family physicians (7114 males [51.5%]; mean [SD] age, 50 [13.1] years) with 12 951 063 patients (6 714 150 females [51.8%]; mean [SD] age, 42.6 [22.9] years) who were attached to these physicians. Most physicians provided between 40% and 80% of care virtually. A higher percentage of the physicians who provided more than 80% of care virtually were 65 years or older, female individuals, and practiced in big cities. Patient comorbidity and morbidity were similar across strata of virtual care use. The mean (SD) number of ED visits was highest among patients whose physicians provided only in-person care (470.3 [1918.8] per 1000 patients) and was lowest among patients of physicians who provided more than 80% to less than 100% of care virtually (242.0 [800.3] per 1000 patients). After adjustment for patient characteristics, patients of physicians with more than 20% of visits delivered virtually had lower rates of ED visits compared with patients of physicians who provided more than 0% to 20% of care virtually (eg, >80% to <100% vs >0%-20% virtual visits in big cities: relative rate, 0.77%; 95% CI, 0.74%-0.81%). This pattern was unchanged across all rurality of practice strata and after adjustment for 2019 ED visit rates. In urban areas, there was a gradient whereby patients of physicians providing the highest level of virtual care had the lowest ED visit rates. Conclusions and Relevance: Findings of this study show that patients of physicians who provided a higher percentage of virtual care did not have higher ED visit rates compared with patients of physicians who provided the lowest levels of virtual care. The findings refute the hypothesis that family physicians providing more care virtually during the pandemic resulted in higher ED use.

SARS-CoV-2 Outbreak Investigation Using Contact Tracing and Whole-Genome Sequencing in an Ontario Tertiary Care Hospital.

Genomic epidemiology can facilitate an understanding of evolutionary history and transmission dynamics of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak. We used next-generation sequencing techniques to study SARS-CoV-2 genomes isolated from patients and health care workers (HCWs) across five wards of a Canadian hospital with an ongoing SARS-CoV-2 outbreak. Using traditional contact tracing methods, we show transmission events between patients and HCWs, which were also supported by the SARS-CoV-2 lineage assignments. The outbreak predominantly involved SARS-CoV-2 B.1.564.1 across all five wards, but we also show evidence of community introductions of lineages B.1, B.1.1.32, and B.1.231, falsely assumed to be outbreak related. Altogether, our study exemplifies the value of using contact tracing in combination with genomic epidemiology to understand the transmission dynamics and genetic underpinnings of a SARS-CoV-2 outbreak. IMPORTANCE Our manuscript describes a SARS-CoV-2 outbreak investigation in an Ontario tertiary care hospital. We use traditional contract tracing paired with whole-genome sequencing to facilitate an understanding of the evolutionary history and transmission dynamics of this SARS-CoV-2 outbreak in a clinical setting. These advancements have enabled the incorporation of phylogenetics and genomic epidemiology into the understanding of clinical outbreaks. We show that genomic epidemiology can help to explore the genetic evolution of a pathogen in real time, enabling the identification of the index case and helping understand its transmission dynamics to develop better strategies to prevent future spread of SARS-CoV-2 in congregate, clinical settings such as hospitals.

Virtual care use prior to emergency department admissions during a stable COVID-19 period in Ontario, Canada.

BACKGROUND: The increased use of telemedicine to provide virtual outpatient visits during the pandemic has led to concerns about potential increased emergency department (ED) admissions and outpatient service use prior to such admissions. We examined the frequency of virtual visits use prior to ED admissions and characterized the patients with prior virtual visit use and the physicians who provided these outpatient visits. METHODS: We conducted a retrospective, population-based, cross-sectional analysis using linked health administrative data in Ontario, Canada to identify patients who had an ED admission between July 1 and September 30, 2021 and patients with an ED admissions during the same period in 2019. We grouped patients based on their use of outpatient services in the 7 days prior to admission and reported their sociodemographic characteristics and healthcare utilization. RESULTS: There were 1,080,334 ED admissions in 2021 vs. 1,113,230 in 2019. In 2021, 74% of these admissions had no prior outpatient visits (virtual or in-person) within 7 days of admission, compared to 75% in 2019. Only 3% of ED admissions had both virtual and in-person visits in the 7 days prior to ED admission. Patients with prior virtual care use were more likely to be hospitalized than those without any outpatient care (13% vs 7.7.%). INTERPRETATION: The net amount of ED admissions and outpatient care prior to admission remained the same over a period of the COVID-19 pandemic when cases were relatively stable. Virtual care seemed to be able to appropriately triage patients to the ED and virtual visits replaced in-person visits ahead of ED admissions, as opposed to being additive.

Outcomes of COVID-19 Infection and Vaccination Among Individuals With Myasthenia Gravis.

Importance: There are limited data regarding COVID-19 outcomes and vaccine uptake and safety among people with myasthenia gravis (MG). Objective: To investigate COVID-19-related outcomes and vaccine uptake among a population-based sample of adults with MG. Design, Setting, and Participants: This population-based, matched cohort study in Ontario, Canada, used administrative health data from January 15, 2020, and August 31, 2021. Adults with MG were identified using a validated algorithm. Each patient was matched by age, sex, and geographic area of residence to 5 controls from the general population and from a cohort of individuals with rheumatoid arthritis (RA). Exposure: Patients with MG and matched controls. Main Outcomes and Measures: Main outcomes were COVID-19 infection and related hospitalizations, intensive care unit admissions, and 30-day mortality among patients with MG vs controls. Secondary outcomes were uptake of COVID-19 vaccination among patients with MG vs controls. Results: Among 11 365 233 eligible Ontario residents, 4411 patients with MG (mean [SD] age, 67.7 [15.6] years; 2274 women [51.6%]) were matched to 22 055 general population controls (mean [SD] age, 67.7 [15.6] years; 11 370 women [51.6%]) and 22 055 controls with RA (mean [SD] age, 67.7 [15.6] years; 11 370 women [51.6%]). In the matched cohort, 38 861 of 44 110 individuals (88.1%) were urban residents; in the MG cohort, 3901 (88.4%) were urban residents. Between January 15, 2020, and May 17, 2021, 164 patients with MG (3.7%), 669 general population controls (3.0%), and 668 controls with RA (3.0%) contracted COVID-19. Compared with general population controls and controls with RA, patients with MG had higher rates of COVID-19-associated emergency department visits (36.6% [60 of 164] vs 24.4% [163 of 669] vs 29.9% [200 of 668]), hospital admissions (30.5% [50 of 164] vs 15.1% [101 of 669] vs 20.7% [138 of 668]), and 30-day mortality (14.6% [24 of 164] vs 8.5% [57 of 669] vs 9.9% [66 of 668]). By August 2021, 3540 patients with MG (80.3%) vs 17 913 general population controls (81.2%) had received 2 COVID-19 vaccine doses, and 137 (3.1%) vs 628 (2.8%), respectively had received 1 dose. Of 3461 first vaccine doses for patients with MG, fewer than 6 individuals were hospitalized for MG worsening within 30 days of vaccination. Vaccinated patients with MG had a lower risk than unvaccinated patients with MG of contracting COVID-19 (hazard ratio, 0.43; 95% CI, 0.30-0.60). Conclusions and Relevance: This study suggests that adults with MG who contracted COVID-19 had a higher risk of hospitalization and death compared with matched controls. Vaccine uptake was high, with negligible risk of severe MG exacerbations after vaccination, as well as evidence of effectiveness. The findings support public health policies prioritizing people with MG for vaccination and new COVID-19 therapeutics.

Association Between Diabetes and Mortality Among Adult Patients Hospitalized With COVID-19: A Cohort Study of Hospitalized Adults in Ontario, Canada, and Copenhagen, Denmark.

OBJECTIVES: Diabetes has been reported to be associated with an increased risk of death among patients with COVID-19. However, the available studies lack detail on COVID-19 illness severity and measurement of relevant comorbidities. METHODS: We conducted a multicentre, retrospective cohort study of patients 18 years of age and older who were hospitalized with COVID-19 between January 1, 2020, and November 30, 2020, in Ontario, Canada, and Copenhagen, Denmark. Chart abstraction emphasizing comorbidities and disease severity was performed by trained research personnel. The association between diabetes and death was measured using Poisson regression. The main outcome measure was in-hospital 30-day risk of death. RESULTS: Our study included 1,133 hospitalized patients with COVID-19 in Ontario and 305 in Denmark, of whom 405 and 75 patients, respectively, had pre-existing diabetes. In both Ontario and Denmark, patients with diabetes were more likely to be older; have chronic kidney disease, cardiovascular disease, and higher troponin levels; and be receiving antibiotics, when compared with adults without diabetes. In Ontario, 24% (n=96) of adults with diabetes died compared with 15% (n=109) of adults without diabetes. In Denmark, 16% (n=12) of adults with diabetes died in hospital compared with 13% (n=29) of those without diabetes. In Ontario, the crude mortality ratio among patients with diabetes was 1.60 (95% confidence interval [CI], 1.24 to 2.07) and in the adjusted regression model it was 1.19 (95% CI, 0.86 to 1.66). In Denmark, the crude mortality ratio among patients with diabetes was 1.27 (95% CI, 0.68 to 2.36) and in the adjusted model it was 0.87 (95% CI, 0.49 to 1.54). Meta-analysis of the 2 rate ratios from each region resulted in a crude mortality ratio of 1.55 (95% CI, 1.22 to 1.96) and an adjusted mortality ratio of 1.11 (95% CI, 0.84 to 1.47). CONCLUSION: The presence of diabetes was not strongly associated with in-hospital COVID-19 mortality independent of illness severity and other comorbidities.

Screening for psychosocial risk in caregivers of children with medical complexity during the COVID-19 pandemic: a cross-sectional study.

OBJECTIVE: The primary objective was to quantify psychosocial risk in family caregivers (FCs) of children with medical complexity (CMC) during the COVID-19 pandemic using the Psychosocial Assessment Tool (PAT). The secondary objectives were to compare this finding with the average PAT score of this population before the COVID-19 pandemic and to examine potential clinical predictors of psychosocial risk in FCs of CMC. DESIGN: Cross-sectional study. PARTICIPANTS: FCs of CMC were recruited from the Long-Term Ventilation Clinic at The Hospital for Sick Children, Toronto, Ontario, Canada. A total of 91 completed the demographic and PAT questionnaires online from 10 June 2021 through 13 December 2021. MAIN OUTCOME MEASURES: Mean PAT scores in FCs were categorised as 'Universal' low risk, 'Targeted' intermediate risk or 'Clinical' high risk. The effect of sociodemographic and clinical variables on overall PAT scores was assessed using multiple linear regression analysis. Comparisons with a previous study were made using Mann-Whitney tests and χ2 analysis. RESULTS: Mean (SD) PAT score was 1.34 (0.69). Thirty-one (34%) caregivers were classified as Universal, 43 (47%) as Targeted and 17 (19%) as Clinical. The mean PAT score (1.34) was significantly higher compared with the mean PAT score (1.17) found prior to the COVID-19 pandemic. Multiple linear regression analysis demonstrated an overall significant model, with the number of hospital admissions since the onset of COVID-19 being the only variable associated with the overall PAT score. CONCLUSION: FCs of CMC are experiencing significant psychosocial stress during the COVID-19 pandemic. Timely and effective interventions are warranted to ensure these individuals receive the appropriate support.

Ethnic disparities in COVID-19 outcomes: a multinational cohort study of 20 million individuals from England and Canada.

BACKGROUND: Heterogeneous studies have demonstrated ethnic inequalities in the risk of SARS-CoV-2 infection and adverse COVID-19 outcomes. This study evaluates the association between ethnicity and COVID-19 outcomes in two large population-based cohorts from England and Canada and investigates potential explanatory factors for ethnic patterning of severe outcomes. METHODS: We identified adults aged 18 to 99 years in the QResearch primary care (England) and Ontario (Canada) healthcare administrative population-based datasets (start of follow-up: 24th and 25th Jan 2020 in England and Canada, respectively; end of follow-up: 31st Oct and 30th Sept 2020, respectively). We harmonised the definitions and the design of two cohorts to investigate associations between ethnicity and COVID-19-related death, hospitalisation, and intensive care (ICU) admission, adjusted for confounders, and combined the estimates obtained from survival analyses. We calculated the 'percentage of excess risk mediated' by these risk factors in the QResearch cohort. RESULTS: There were 9.83 million adults in the QResearch cohort (11,597 deaths; 21,917 hospitalisations; 2932 ICU admissions) and 10.27 million adults in the Ontario cohort (951 deaths; 5132 hospitalisations; 1191 ICU admissions). Compared to the general population, pooled random-effects estimates showed that South Asian ethnicity was associated with an increased risk of COVID-19 death (hazard ratio: 1.63, 95% CI: 1.09-2.44), hospitalisation (1.53; 1.32-1.76), and ICU admission (1.67; 1.23-2.28). Associations with ethnic groups were consistent across levels of deprivation. In QResearch, sociodemographic, lifestyle, and clinical factors accounted for 42.9% (South Asian) and 39.4% (Black) of the excess risk of COVID-19 death. CONCLUSION: International population-level analyses demonstrate clear ethnic inequalities in COVID-19 risks. Policymakers should be cognisant of the increased risks in some ethnic populations and design equitable health policy as the pandemic continues.