Individual and social determinants of SARS-CoV-2 testing and positivity in Ontario, Canada: a population-wide study

COVID-19 hospitalization, mortality and pre-mature mortality by a history of immigration in Ontario, Canada: a population-based cohort study

Background

Immigrants in high-income countries experienced inequities in COVID-19 severe outcomes. We examined hospitalization and death throughout the pandemic, and change during the vaccine era, in Ontario, Canada.

Methods

We conducted a population-based study using linked immigration and health data, following two cohorts for 20 months from January 1, 2020 (pre-vaccine) and September 1, 2021 (vaccine era). We used multivariable Poisson generalized estimating equation regression to estimate adjusted rate ratios (aRR) with 95% confidence intervals (CI), accounting for age, sex and co-morbidities. We calculated age-standardized years of life lost (ASYRs) rates by immigrant category.

Findings

Of 11,692,387 community-dwelling adults in the pre-vaccine era cohort and 11,878,304 community-dwelling adults in the vaccine era cohort, 21.6% and 21.4% of adults in each era respectively were immigrants. Females accounted for 57.9% and 57.8% of sponsored family, and 68.4% and 67.6% of economic caregivers, in each era respectively. Compared to other Ontarians in the pre-vaccine era cohort, hospitalization rates were highest for refugees (aRR [95% CI] 3.41 [3.39-3.44]) and caregivers (3.13 [3.07-3.18]), followed by sponsored family and other economic immigrants. Compared to other Ontarians, aRRs were highest for immigrants from Central America (5.00 [4.92-5.09]), parts of South Asia (3.95 [3.89-4.01]) and Jamaica (3.56 [3.51-3.61]) with East Asians having lower aRRs. Mortality aRRs were similar to hospitalization aRRs. In the vaccine era, all aRRs were attenuated and most were similar to or lower than other Ontarians, with refugees and a few regions maintaining higher rates. In the pre-vaccine era ASYRs were higher for all immigrant groups. ASYRs dropped in the vaccine era with only refugees continuing to have higher rates.

Interpretation

Immigrants, particularly refugees, experienced greater premature mortality. aRRs for most immigrant groups dropped substantially after high vaccine coverage was achieved. Vaccine outreach and improvements in the social determinants of health are needed.

Funding

Canadian Institutes of Health Research, Canada Research Chairs Program.

The Impacts of COVID-19 Restrictions on Quality Adjusted Life Years (QALY): Heterogeneous effects and post-pandemic recovery

OBJECTIVES

Estimate the effects of non-pharmacological interventions used to prevent the spread of COVID-19 on the quality of life, measured by Quality Adjusted Life Years (QALYs).

METHODS

A survey on 1,506 heads of households from Chile in May of 2022. Respondents were asked basic socioeconomic questions and a version of the EQ-5D-5L questionnaire that was used to calculate the evolution of HRQoLs. Comparisons of means in HRQoLs measures before the pandemic, at the peak of restrictions, and at the moment of the survey were performed.

RESULTS

The average HRQoL of the population before the pandemic was similar to other countries in the region (0.96). At the peak of restrictions (June 2020-August 2021), the average HRQoL decreased to 0.87 (-9%). At the time of survey (May 2022), the average HQRoL was 0.91 (4%). Assuming the recovery trend continued, pre-pandemic HRQoLs would be reached by January 2024. Altogether, the pandemic would have reduced QALYs by 0.2 in average. The effect is larger and the recovery slower among women. Our estimates imply that the restrictions to manage the pandemic came at a cost of 2.4 months of life years for the average (surviving) person, 1.8 months for men and 3.4 for women.

CONCLUSIONS

Our results suggest that COVID-19 had worse effects on life quality than previously thought. These effects are more significant among women than among men. Efforts to improve life quality and speed up its recovery could have large positive consequences for the population.

Have immigrant children been left behind in COVID-19 testing rates? - A quantitative study in the Lisbon metropolitan area between march 2020 and may 2023

Immigrant children often encounter additional barriers in accessing health care than their peers. However, there is a lack of evidence globally regarding how migrant status may have affected access to COVID-19 testing during the pandemic. This study aimed to analyze migrant status as a determinant of COVID-19 testing rates among children in the Lisbon metropolitan area, Portugal. This cross-sequential study included 722 children aged 2-8 years (47% non-immigrants; 53% immigrants). We collected data from a national surveillance system on laboratory-confirmed COVID-19 tests conducted between March 2020 and May 2023 and assessed whether children were ever tested for COVID-19 and testing frequency. We employed robust and standard Poisson regression models to estimate Adjusted Prevalence Ratios and Relative Risks with 95% confidence intervals. A total of 637 tests were performed. Immigrant children had lower testing rates (53% vs. 48%) and fewer tests per child (median: 2 vs. 3). Moreover, they were 17% less likely to be ever tested (PR = 0.83, 95% CI: 0.76-0.89) and performed 26% fewer tests (RR = 0.74, 95% CI: 0.67-0.82) compared to non-immigrant children. Caregiver's age, education, employment status, child's birth weight, and perceived health status were associated factors. Our findings suggest that the COVID-19 pandemic has left immigrant children somewhat behind. We conclude that specific interventions targeting vulnerable populations, such as immigrant children, are needed in future health crises.

Predictors of later COVID-19 test seeking

Background

Delays in COVID-19 testing may increase the risk of secondary household and community transmission. Little is known about what patient characteristics and symptom profiles are associated with delays in test seeking.

Methods

We conducted a retrospective cohort study of all symptomatic patients diagnosed with COVID-19 and assessed in a COVID Expansion to Outpatients (COVIDEO) virtual care program between March 2020 and June 2021. The primary outcome was later test seeking more than 3 days from symptom onset. Multivariable logistic regression was used to examine predictors of later testing including patient characteristics and symptoms (30 individual symptoms or 7 symptom clusters).

Results

Of 5,363 COVIDEO patients, 4,607 were eligible and 2,155/4,607 (46.8%) underwent later testing. Older age was associated with increased odds of late testing (adjusted odds ratio [aOR] 1.007/year; 95% CI 1.00 to 1.01), as was history of recent travel (aOR 1.4; 95% CI 1.01 to 1.95). Health care workers had lower odds of late testing (aOR 0.50; 95% CI 0.39 to 0.62). Late testing was associated with symptoms in the cardiorespiratory (aOR 1.2; 95% CI 1.05, 1.36), gastrointestinal (aOR = 1.2; 95% CI 1.04, 1.4), neurological (aOR 1.1; 95% CI 1.003, 1.3) and psychiatric (aOR 1.3; 95% CI 1.1, 1.5) symptom clusters. Among individual symptoms, dyspnea, anosmia, dysgeusia, sputum, and anorexia were associated with late testing; pharyngitis, myalgia, and headache were associated with early testing.

Conclusion

Certain patient characteristics and symptoms are associated with later testing, and warrant further efforts to encourage earlier testing to minimize transmission.

Impact of the COVID-19 Pandemic on Physical Activity among Mostly Older, Overweight Black Women Living in the Rural Alabama Black Belt

Despite well-documented global declines in physical activity (PA) during the COVID-19 pandemic, little is known regarding the specific impact among underserved, rural Alabama counties. This is concerning as this region was already disproportionately burdened by inactivity and related chronic diseases and was among the hardest hit by COVID-19. Thus, the current study examined the effect of COVID-19 on PA in four rural Alabama counties. An ancillary survey was administered between March 2020 and August 2021 to the first cohort (N = 171) of participants enrolled in a larger PA trial. Main outcomes of this survey included the perceived impact of COVID-19 on PA, leisure-time PA, and social cognitive theory (SCT) constructs at 3 months. Almost half of the participants reported being less active during the pandemic (49.7%) and endorsed that COVID-19 made PA more difficult (47.4%), citing concerns such as getting sick from exercising outside of the home (70.4%) and discomfort wearing a face mask while exercising (58%). Perceived COVID-19 impact on PA was significantly associated with education, household dependents, and gender (p's < 0.05). More women, parents, and college graduates reported that the COVID-19 pandemic made PA more difficult. Overall, there were no significant associations between PA, SCT constructs, or perceived COVID-19 impact on PA scores at 3 months. While the pandemic made PA difficult for many participants, these barriers were not associated with leisure-time PA levels or related theoretical mechanisms of action, which bodes well for the success of our ongoing intervention efforts and the resiliency of these communities.

Developing the intersectionality supplemented Consolidated Framework for Implementation Research (CFIR) and tools for intersectionality considerations

BACKGROUND

The concept of intersectionality proposes that demographic and social constructs intersect with larger social structures of oppression and privilege to shape experiences. While intersectionality is a widely accepted concept in feminist and gender studies, there has been little attempt to use this lens in implementation science. We aimed to supplement the Consolidated Framework for Implementation Research (CFIR), a commonly used framework in implementation science, to support the incorporation of intersectionality in implementation science projects by (1) integrating an intersectional lens to the CFIR; and (2) developing a tool for researchers to be used alongside the updated framework.

METHODS

Using a nominal group technique, an interdisciplinary framework committee (n = 17) prioritized the CFIR as one of three implementation science models, theories, and frameworks to supplement with intersectionality considerations; the modification of the other two frameworks are described in other papers. The CFIR subgroup (n = 7) reviewed the five domains and 26 constructs in the CFIR and prioritized domains and constructs for supplementation with intersectional considerations. The subgroup then iteratively developed recommendations and prompts for incorporating an intersectional approach within the prioritized domains and constructs. We developed recommendations and prompts to help researchers consider how personal identities and power structures may affect the facilitators and inhibitors of behavior change and the implementation of subsequent interventions.

RESULTS

We achieved consensus on how to apply an intersectional lens to CFIR after six rounds of meetings. The final intersectionality supplemented CFIR includes the five original domains, and 28 constructs; the outer systems and structures and the outer cultures constructs were added to the outer setting domain. Intersectionality prompts were added to 13 of the 28 constructs.

CONCLUSION

Through an expert-consensus approach, we modified the CFIR to include intersectionality considerations and developed a tool with prompts to help implementation users apply an intersectional lens using the updated framework.

Comparison of socio-economic determinants of COVID-19 testing and positivity in Canada: A multi-provincial analysis

BACKGROUND

The effects of the COVID-19 pandemic have been more pronounced for socially disadvantaged populations. We sought to determine how access to SARS-CoV-2 testing and the likelihood of testing positive for COVID-19 were associated with demographic factors, socioeconomic status (SES) and social determinants of health (SDH) in three Canadian provinces.

METHODS

An observational population-based cross-sectional study was conducted for the provinces of Ontario, Manitoba and New Brunswick between March 1, 2020 and April 27, 2021, using provincial health administrative data. After excluding residents of long-term care homes, those without current provincial health insurance and those who were tested for COVID-19 out of province, records from provincial healthcare administrative databases were reviewed for 16,900,661 healthcare users. Data was modelled separately for each province in accordance to a prespecified protocol and follow-up consultations among provincial statisticians and collaborators. We employed univariate and multivariate regression models to examine determinants of testing and test results.

RESULTS

After adjustment for other variables, female sex and urban residency were positively associated with testing, while female sex was negatively associated with test positivity. In New Brunswick and Ontario, individuals living in higher income areas were more likely to be tested, whereas in Manitoba higher income was negatively associated with both testing and positivity. High ethnocultural composition was associated with lower testing rates. Both high ethnocultural composition and high situational vulnerability increased the odds of testing positive for SARS-CoV-2.

DISCUSSION

We observed that multiple demographic, income and SDH factors were associated with SARS-CoV-2 testing and test positivity. Barriers to healthcare access identified in this study specifically relate to COVID-19 testing but may reflect broader inequities for certain at-risk groups.

SARS-CoV-2 Infection, Hospitalization, and Mortality in Adults With and Without Cancer

Importance

Patients with cancer are at increased risk of SARS-CoV-2-associated adverse outcomes.

Objective

To determine the associations of tumor type with SARS-CoV-2 infection, hospitalization, intensive care unit (ICU) admission, and death.

Design, Setting, and Participants

This retrospective, population-based cohort study included community-dwelling adults aged at least 18 years in Ontario, Canada, ICES-linked provincial health databases from January 1, 2020, to November 30, 2021. Data were analyzed from December 1, 2021, to November 1, 2022.

Exposures

Cancer diagnosis.

Main Outcomes and Measures

The primary outcome was SARS-CoV-2 infection, and secondary outcomes included all-cause 14-day hospitalization, 21-day ICU admission, and 28-day death following SARS-CoV-2 infection. Cox proportional hazards models were used to obtain adjusted hazard ratios (aHRs) and 95% CIs.

Results

Of 11 732 108 people in the ICES-linked health databases, 279 287 had cancer (57.2% female; mean [SD] age, 65.9 [16.1] years) and 11 452 821 people did not have cancer (45.7% female; mean [SD] age, 65.9 [16.0] years). Overall, 464 574 individuals (4.1%) developed SARS-CoV-2 infection. Individuals with hematologic malignant neoplasms (33 901 individuals) were at increased risk of SARS-CoV-2 infection (aHR, 1.19; 95% CI, 1.13-1.25), 14-day hospitalization (aHR, 1.75; 95% CI, 1.57-1.96), and 28-day mortality (aHR, 2.03; 95% CI, 1.74-2.38) compared with the overall population, while individuals with solid tumors (245 386 individuals) were at lower risk of SARS-CoV-2 infection (aHR, 0.93; 95% CI, 0.91-0.95) but increased risk of 14-day hospitalization (aHR, 1.11; 95% CI, 1.05-1.18) and 28-day mortality (aHR, 1.31; 95% CI, 1.19-1.44). The 28-day mortality rate was high in hospitalized patients with hematologic malignant neoplasms (163 of 321 hospitalized patients [50.7%]) or solid tumors (486 of 1060 hospitalized patients [45.8%]). However, the risk of 21-day ICU admission in patients with hematologic malignant neoplasms (aHR, 1.14; 95% CI, 0.93-1.40) or solid tumors (aHR, 0.93; 95% CI, 0.82-1.05) was not significantly different from that among individuals without cancer. The SARS-CoV-2 infection risk decreased stepwise with increasing numbers of COVID-19 vaccine doses received (1 dose: aHR, 0.63; 95% CI, 0.62-0.63; 2 doses: aHR, 0.16; 95% CI, 0.16-0.16; 3 doses: aHR, 0.05; 95% CI, 0.04-0.06).

Conclusions and Relevance

These findings highlight the importance of prioritization strategies regarding ICU access to reduce the mortality risk in increased-risk populations, such as patients with cancer.

SARS-CoV-2 testing and COVID-19-related primary care use among people with citizenship, permanent residency, and temporary immigration status: an analysis of population-based administrative data in British Columbia

OBJECTIVES

Having temporary immigration status affords limited rights, workplace protections, and access to services. There is not yet research data on impacts of the COVID-19 pandemic for people with temporary immigration status in Canada.

METHODS

We use linked administrative data to describe SARS-CoV-2 testing, positive tests, and COVID-19 primary care service use in British Columbia from January 1, 2020 to July 31, 2021, stratified by immigration status (citizen, permanent resident, temporary resident). We plot the rates of people tested and confirmed positive for COVID-19 by week from April 19, 2020 to July 31, 2021 across immigration groups. We use logistic regression to estimate adjusted odds ratios of a positive SARS-CoV-2 test, access to testing, and primary care among people with temporary status or permanent residency, compared with people who hold citizenship.

RESULTS

A total of 4,146,593 people with citizenship, 914,089 people with permanent residency, and 212,215 people with temporary status were included. Among people with temporary status, 52.1% had "male" administrative sex and 74.4% were ages 20-39, compared with 50.1% and 24.4% respectively among those with citizenship. Of people with temporary status, 4.9% tested positive for SARS-CoV-2 over this period, compared with 4.0% among people with permanent residency and 2.1% among people with citizenship. Adjusted odds of a positive SARS-CoV-2 test among people with temporary status were almost 50% higher (aOR 1.42, 95% CI 1.39, 1.45), despite having half the odds of access to testing (aOR 0.53, 95% CI 0.53, 0.54) and primary care (aOR 0.50, 95% CI 0.49, 0.52).

CONCLUSION

Interwoven immigration, health, and occupational policies place people with temporary status in circumstances of precarity and higher health risk. Reducing precarity accompanying temporary status, including regularization pathways, and decoupling access to health care from immigration status can address health inequities.

Racial/ethnic and socioeconomic disparities in COVID-19 infections among working-age women with precancerous cervical lesion in Louisiana: analysis of more than two years of COVID-19 data

Background

Precancerous cervical lesion (PCL) is common in working-age and minority women. In Louisiana, 98% of PCL cases were diagnosed at age 18-65 with over 90% of them being human papillomavirus (HPV)-related. PCL women represent those who may be immunocompromised from the precancerous condition and thus more vulnerable to SARS-CoV-2. Most studies evaluating racial disparities for COVID-19 infection have only used data prior to vaccine availability. This study assessed disparities by race/ethnicity and socioeconomic status (SES) in COVID-19 infections among working-age PCL women for pre- and post-COVID-19 vaccine availability.

Methods

Louisiana women aged 18-65 with PCL diagnosed in 2009-2021 were linked with the Louisiana statewide COVID-19 database to identify those with positive COVID-19 test. Race/ethnicity was categorized as non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic, and others. The census tract SES quintiles were created based on American Community Survey estimates. Logistic regression was employed to assess the racial/ethnic and SES differences in COVID-19 infections.

Results

Of 14,669 eligible PCL women, 30% were tested COVID-19 positive. NHB had the highest percentage of COVID-19 infection (34.6%), followed by NHW (27.7%). The infection percentage was inversely proportional to SES, with 32.9% for women having the lowest SES and 26.8% for those with the highest SES. NHB women and those with lower SES had higher COVID-19 infection than their counterparts with an aOR of 1.37 (95% CI 1.25-1.49) and 1.21 (95% CI 1.07-1.37), respectively. In the pre-vaccine period, NHB and Hispanic women had higher odds of infection than NHW women. However, after the vaccine was implemented, the significant racial/ethnic and SES differences in COVID-19 infections still existed in PCL women residing in non-Greater New Orleans area.

Conclusions

There are substantial variations in racial/ethnic and SES disparities in COVID-19 infections among working-age women with PCL, even after vaccine implementation. It is imperative to provide public health interventions and resources to reduce this unequal burden for this vulnerable population.

Particulate matter air pollution and COVID-19 infection, severity, and mortality: A systematic review and meta-analysis

Ecological evidence links ambient particulate matter ≤2.5 mm (PM_2.5) and the rate of COVID-19 infections, severity, and deaths. However, such studies are unable to account for individual-level differences in major confounders like socioeconomic status and often rely on imprecise measures of PM_2.5. We conducted a systematic review of case-control and cohort studies, which rely on individual-level data, searching Medline, Embase, and the WHO COVID-19 database up to 30 June 2022. Study quality was evaluated using the Newcastle-Ottawa Scale. Results were pooled with a random effects meta-analysis, with Egger's regression, funnel plots, and leave-one-out/trim-and-fill sensitivity analyses to account for publication bias. N = 18 studies met inclusion criteria. A 10 μg/m³ increase in PM_2.5 was associated with 66 % (95 % CI: 1.31-2.11) greater odds of COVID-19 infection (N = 7) and 127 % (95 % CI: 1.41-3.66) odds of severe illness (hospitalisation, ICU admission, or requiring respiratory support) (N = 6). Pooled mortality results (N = 5) indicated increased deaths due to PM_2.5 but were non-significant (OR 1.40; 0.94 to 2.10). Most studies were rated "good" quality (14/18 studies), though there were numerous methodological issues; few used individual-level data to adjust for socioeconomic status (4/18 studies), instead using area-based indicators (11/18 studies) or no such adjustments (3/18 studies). Most severity (9/10 studies) and mortality studies (5/6 studies) were based on people already diagnosed COVID-19, potentially introducing collider bias. There was evidence of publication bias in studies of infection (p = 0.012) but not severity (p = 0.132) or mortality (p = 0.100). While methodological limits and evidence of bias require cautious interpretation of the findings, we found compelling evidence that PM_2.5 increases the risk of COVID-19 infection and severe disease, and weaker evidence of an increase in mortality risk.

Differential Patterns by Area-Level Social Determinants of Health in Coronavirus Disease 2019 (COVID-19)-Related Mortality and Non-COVID-19 Mortality: A Population-Based Study of 11.8 Million People in Ontario, Canada

BACKGROUND

Social determinants of health (SDOH) have been associated with coronavirus disease 2019 (COVID-19) outcomes. We examined patterns in COVID-19-related mortality by SDOH and compared these patterns to those for non-COVID-19 mortality.

METHODS

Residents of Ontario, Canada, aged ≥20 years were followed from 1 March 2020 to 2 March 2021. COVID-19-related death was defined as death within 30 days following or 7 days prior to a positive COVID-19 test. Area-level SDOH from the 2016 census included median household income; proportion with diploma or higher educational attainment; proportion essential workers, racially minoritized groups, recent immigrants, apartment buildings, and high-density housing; and average household size. We examined associations between SDOH and COVID-19-related mortality, and non-COVID-19 mortality using cause-specific hazard models.

RESULTS

Of 11 810 255 individuals, we observed 3880 COVID-19-related deaths and 88 107 non-COVID-19 deaths. After accounting for demographics, baseline health, and other area-level SDOH, the following were associated with increased hazards of COVID-19-related death (hazard ratio [95% confidence interval]: lower income (1.30 [1.04-1.62]), lower educational attainment (1.27 [1.07-1.52]), higher proportions essential workers (1.28 [1.05-1.57]), racially minoritized groups (1.42 [1.08-1.87]), apartment buildings (1.25 [1.07-1.46]), and large vs medium household size (1.30 [1.12-1.50]). Areas with higher proportion racially minoritized groups were associated with a lower hazard of non-COVID-19 mortality (0.88 [0.84-0.92]).

CONCLUSIONS

Area-level SDOH are associated with COVID-19-related mortality after accounting for demographic and clinical factors. COVID-19 has reversed patterns of lower non-COVID-19 mortality among racially minoritized groups. Pandemic responses should include strategies to address disproportionate risks and inequitable coverage of preventive interventions associated with SDOH.

Effects of school-level and area-level socio-economic factors on elementary school student COVID-19 infections: a population-based observational study

OBJECTIVES

To estimate the variability of the cumulative incidence of SARS-CoV-2 infections among elementary school students attributable to individual schools and/or their geographic areas, and to ascertain whether socio-economic characteristics of school populations and/or geographic areas may be predictive of this variability.

DESIGN

Population-based observational study of SARS-CoV-2 infections among elementary school children.

SETTING

3994 publicly funded elementary schools in 491 forward sortation areas (designated geographic unit based on first three characters of Canadian postal code), Ontario, Canada, September 2020 to April 2021.

PARTICIPANTS

All students attending publicly funded elementary schools with a positive molecular test for SARS-CoV-2 reported by the Ontario Ministry of Education.

MAIN OUTCOME MEASURES

Cumulative incidence of laboratory-confirmed elementary school student SARS-CoV-2 infections in Ontario, 2020-21 school year.

RESULTS

A multilevel modelling approach was used to estimate the effects of socio-economic factors at the school and area levels on the cumulative incidence of elementary school student SARS-CoV-2 infections. At the school level (level 1), the proportion of the student body from low-income households was positively associated with cumulative incidence (β=0.083, p<0.001). At the area level (level 2), all dimensions of marginalisation were significantly related to cumulative incidence. Ethnic concentration (β=0.454, p<0.001), residential instability (β=0.356, p<0.001) and material deprivation (β=0.212, p<0.001) were positively related, while dependency (β=-0.204, p<0.001) was negatively related. Area-related marginalisation variables explained 57.6% of area variability in cumulative incidence. School-related variables explained 1.2% of school variability in cumulative incidence.

CONCLUSIONS

The socio-economic characteristics of the geographic area of schools were more important in accounting for the cumulative incidence of SARS-CoV-2 elementary school student infections than individual school characteristics. Schools in marginalised areas should be prioritised for infection prevention measures and education continuity and recovery plans.

Trajectories of the socioeconomic gradient of mental health: Results from the CLSA COVID-19 Questionnaire Study

As the coronavirus disease (COVID-19) pandemic prolongs, documenting trajectories of the socioeconomic gradient of mental health is important. We describe changes in the prevalence and absolute and relative income-related inequalities of mental health between April and December 2020 in Canada. We used data from the Canadian Longitudinal Study on Aging (CLSA) COVID-19 Questionnaire Study and the pre-pandemic CLSA Follow-up 1. We estimated the prevalence proportion, the concentration index (relative inequality), and the generalized concentration index (absolute inequality) for anxiety and self-reported feeling generally unwell at multiple points in April-December 2020, overall, by sex and age group, by region, and among those who reported poor or fair overall health and mental health pre-pandemic. Overall, the prevalence of anxiety remained unchanged (22.45 to 22.10%, p = 0.231), but self-reported feeling generally unwell decreased (9.83 to 5.94%, p = 0.004). Relative and absolute income-related inequalities were unchanged for both anxiety and self-reported feeling generally unwell, with exceptions of an increased concentration of self-reported feeling generally unwell among the poor, measured by the concentration index, overall (-0.054 to -0.115, p = 0.004) and in Ontario (-0.035 to -0.123, p = 0.047) and British Columbia (-0.055 to -0.141, p = 0.044). The COVID-19 pandemic appeared to neither exacerbate nor ameliorate existing income-related inequalities in mental health among older adults in Canada between April and December 2020. Continued monitoring of inequalities is necessary.

Geographic clustering of travel-acquired infections in Ontario, Canada, 2008-2020

As the frequency of international travel increases, more individuals are at risk of travel-acquired infections (TAIs). In this ecological study of over 170,000 unique tests from Public Health Ontario's laboratory, we reviewed all laboratory-reported cases of malaria, dengue, chikungunya, and enteric fever in Ontario, Canada between 2008-2020 to identify high-resolution geographical clusters for potential targeted pre-travel prevention. Smoothed standardized incidence ratios (SIRs) and 95% posterior credible intervals (CIs) were estimated using a spatial Bayesian hierarchical model. High- and low-incidence areas were described using data from the 2016 Census based on the home forward sortation area of patients testing positive. A second model was used to estimate the association between drivetime to the nearest travel clinic and incidence of TAI within high-incidence areas. There were 6,114 microbiologically confirmed TAIs across Ontario over the study period. There was spatial clustering of TAIs (Moran's I = 0.59, p<0.0001). Compared to low-incidence areas, high-incidence areas had higher proportions of immigrants (p<0.0001), were lower income (p = 0.0027), had higher levels of university education (p<0.0001), and less knowledge of English/French languages (p<0.0001). In the high-incidence Greater Toronto Area (GTA), each minute increase in drive time to the closest travel clinic was associated with a 3% reduction in TAI incidence (95% CI 1-6%). While urban neighbourhoods in the GTA had the highest burden of TAIs, geographic proximity to a travel clinic in the GTA was not associated with an area-level incidence reduction in TAI. This suggests other barriers to seeking and adhering to pre-travel advice.

Which Curve Are We Flattening? The Disproportionate Impact of COVID-19 Among Economically Marginalized Communities in Ontario, Canada, Was Unchanged From Wild-Type to Omicron

Person-level surveillance (N = 14 million) and neighborhood-level income data were used to explore magnitude of inequalities in COVID-19 hospitalizations and deaths over 5 waves in Ontario, Canada. Despite attempts at equity-informed policies alongside fluctuating levels of public health measures, the magnitude of inequalities in hospitalizations and deaths remained unchanged across waves.

Excess deaths during the COVID-19 pandemic in Alberta, Canada

Objectives

To determine if there was excess mortality in Alberta, Canada during the coronavirus disease 2019 (COVID-19) pandemic, to confirm if excess mortality affected all age groups equally, and to determine what proportions of excess deaths were directly related to COVID-19 and non-pharmaceutical drug poisoning.

Methods

Weekly all-cause data used to estimate excess mortality were modelled against the pre-pandemic period (January 2015-February 2020). Age-adjusted weekly mortality rates for March 2020 to December 2021 were compared with the preceding 5 years.

Results

From March 2020 to December 2021, there was an 11% excess mortality rate, corresponding to an average of 265 monthly excess deaths (maximum >30%). COVID-19-related deaths (n=3202) accounted for 54.9% of total excess deaths (n=5833) that occurred in the 22-month period. The increase in all-cause excess deaths was proportionately higher, and with significantly greater numbers, in younger age groups. Significant increases in monthly drug poisoning deaths occurred from March 2020 to April 2021, with a total of 1819 deaths. Eight hundred and 25 excess drug poisoning deaths, representing 25.4% of total all-cause excess deaths, occurred, mainly among those aged 25-60 years. Overall, 54.9% of all excess deaths were directly related to COVID-19 and 25.4% were related to drug poisoning.

Conclusions

There was a significant increase in all-cause mortality during the COVID-19 pandemic. Although older adults are more likely to die of COVID-19, a massive increase in non-COVID-19-related mortality was observed among younger people. These factors should be considered in public policy decisions on epidemic/pandemic management.

Neighbourhood-level socio-demographic characteristics and risk of COVID-19 incidence and mortality in Ontario, Canada: A population-based study

OBJECTIVES

We aimed to estimate associations between COVID-19 incidence and mortality with neighbourhood-level immigration, race, housing, and socio-economic characteristics.

METHODS

We conducted a population-based study of 28,808 COVID-19 cases in the provincial reportable infectious disease surveillance systems (Public Health Case and Contact Management System) which includes all known COVID-19 infections and deaths from Ontario, Canada reported between January 23, 2020 and July 28, 2020. Residents of congregate settings, Indigenous communities living on reserves or small neighbourhoods with populations <1,000 were excluded. Comparing neighbourhoods in the 90th to the 10th percentiles of socio-demographic characteristics, we estimated the associations between 18 neighbourhood-level measures of immigration, race, housing and socio-economic characteristics and COVID-19 incidence and mortality using Poisson generalized linear mixed models.

RESULTS

Neighbourhoods with the highest proportion of immigrants (relative risk (RR): 4.0, 95%CI:3.5-4.5) and visible minority residents (RR: 3.3, 95%CI:2.9-3.7) showed the strongest association with COVID-19 incidence in adjusted models. Among individual race groups, COVID-19 incidence was highest among neighbourhoods with the high proportions of Black (RR: 2.4, 95%CI:2.2-2.6), South Asian (RR: 1.9, 95%CI:1.8-2.1), Latin American (RR: 1.8, 95%CI:1.6-2.0) and Middle Eastern (RR: 1.2, 95%CI:1.1-1.3) residents. Neighbourhoods with the highest average household size (RR: 1.9, 95%CI:1.7-2.1), proportion of multigenerational families (RR: 1.8, 95%CI:1.7-2.0) and unsuitably crowded housing (RR: 2.1, 95%CI:2.0-2.3) were associated with COVID-19 incidence. Neighbourhoods with the highest proportion of residents with less than high school education (RR: 1.6, 95%CI:1.4-1.8), low income (RR: 1.4, 95%CI:1.2-1.5) and unaffordable housing (RR: 1.6, 95%CI:1.4-1.8) were associated with COVID-19 incidence. Similar inequities were observed across neighbourhood-level sociodemographic characteristics and COVID-19 mortality.

CONCLUSIONS

Neighbourhood-level inequities in COVID-19 incidence and mortality were observed in Ontario, with excess burden experienced in neighbourhoods with a higher proportion of immigrants, racialized populations, large households and low socio-economic status.

Community-based SARS-CoV-2 testing in low-income neighbourhoods in Rotterdam: Results from a pilot study

Background

High incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and low testing uptake were reported in low-income neighbourhoods in Rotterdam. We aimed to improve willingness and access to testing by introducing community-based test facilities, and to evaluate the effectiveness of a rapid antigen detection test (RDT).

Methods

Two to eleven test facilities operated consecutively in three low-income neighbourhoods in Rotterdam, offering the options of walk-in or appointments. Background characteristics were collected at intake and one nasopharyngeal swab was taken and processed using both RDT and reverse transcription polymerase chain reaction (RT-PCR). Visitors were asked to join a survey for evaluation purposes.

Results

In total, 19 773 visitors were tested - 9662 (48.9%) without an appointment. Walk-in visitors were older, lived more often in the proximity of the test facilities, and reported coronavirus disease (COVID-19)-related symptoms less often than by-appointment visitors. For 67.7% of the visitors, this was the first time they got tested. A total of 1211 (6.1%) tested SARS-CoV-2-positive with RT-PCR, of whom 309 (25.5%) were asymptomatic. Test uptake increased among residents of the pilot neighbourhoods, especially in the older age groups, compared to people living in comparable neighbourhoods without community-based testing facilities. RDT detected asymptomatic individuals with 71.8% sensitivity, which was acceptable in this high prevalence setting. Visitors reported positive attitudes towards the test facilities and welcomed the easy access.

Conclusions

Offering community-based SARS-CoV-2 testing seems a promising approach for increasing testing uptake among specific populations in low-income neighbourhoods.

Understanding COVID-19 Risk in Patients With Immune-Mediated Inflammatory Diseases: A Population-Based Analysis of SARS-CoV-2 Testing

OBJECTIVE

To investigate the incidence of and factors associated with SARS-CoV-2 testing and infection in immune-mediated inflammatory disease (IMID) patients versus matched non-IMID comparators from the general population.

METHODS

We conducted a population-based, matched cohort study among adult residents from Ontario, Canada, from January 2020 to December 2020. We created cohorts for the following IMIDs: rheumatoid arthritis (RA), psoriasis, psoriatic arthritis, ankylosing spondylitis, systemic autoimmune rheumatic diseases, multiple sclerosis (MS), iritis, inflammatory bowel disease (IBD), polymyalgia rheumatica, and vasculitis. Each patient was matched with 5 patients without IMIDs based on sociodemographic factors. We estimated the incidence of SARS-CoV-2 testing and infection in IMID patients and non-IMID patients. Multivariable logistic regressions assessed odds of SARS-CoV-2 infection.

RESULTS

We studied 493,499 patients with IMIDs and 2,466,946 patients without IMIDs. Patients with IMIDs were more likely to have at least 1 SARS-CoV-2 test versus patients without IMIDs (27.4% versus 22.7%), but the proportion testing positive for SARS-CoV-2 was identical (0.9% in both groups). Overall, IMID patients had 20% higher odds of being tested for SARS-CoV-2 (odds ratio 1.20 [95% confidence interval 1.19-1.21]). The odds of SARS-CoV-2 infection varied across IMID groups but was not significantly elevated for most IMID groups compared with non-IMID comparators. The odds of SARS-CoV-2 infection was lower in IBD and MS and marginally higher in RA and iritis.

CONCLUSION

Patients across all IMIDs were more likely to be tested for SARS-CoV-2 versus those without IMIDs. The risk of SARS-CoV-2 infection varied across disease subgroups.

[Social determinants associated with self-reporting of symptoms and access to COVID-19 testing and diagnosis in the Plurinational State of BoliviaDeterminantes sociais associados ao autorrelato de sintomas, acesso a testagem e diagnóstico de COVID-19 no Estado Plurinacional da Bolívia]

Objective

To identify the prevalence of self-reporting of symptoms and access to testing and diagnosis of coronavirus-19 disease (COVID-19), as well as its association with social determinants of health (SDH).

Methods

Cross-sectional study with a sample of 11 728 men and 12 612 women over the age of 17, based on the National Household Survey 2020. The dependent variables were the self-reporting of symptoms, access to testing, and a positive COVID-19 test. The independent variables were age, educational level, area of residence and geographic area, ethnicity, type of household, income per capita, occupation, and health insurance. Prevalences, bivariate associations, and binomial logistical regression models (odds ratio (OR), and 95% confidence interval (CI95%) were calculated.

Results

Of the total individuals included, 16% reported symptoms, 10% a test, and 4.2% a positive COVID-19 test. Inequalities were observed in the reporting of COVID-19 symptoms, with a higher probability in women whose income had fallen (OR: 1.7; CI95%: 1.2-2.4) and unemployed persons (OR: 1.2; CI95%: 1.1-1.4 for men and OR: 1.3; CI95%: 1.5-1.5 for women). In contrast, with respect to access to diagnostic tests, the highest probability was observed in people with higher education (OR: 2.4; CI95%: 1.9-2.9 for men and OR: 2.7; CI95%: 2.2-3.4 for women), whose income was maintained (OR: 1.5; CI95%: 1.3-1.9 for men and OR: 1.7; CI95%: 1.4-2.0 for women) and those in the highest quartile of per capita household income (OR: 2.0; CI95%: 1.6-2.5 for men and OR: 1.6; CI95%: 1.3-2.0 for women). The probability of reporting symptoms and getting tested, and being diagnosed with COVID-19 increased with age for people with health insurance and those living in the llanos region; however, it decreased for residents of rural areas.

Conclusions

There are inequalities in access to testing and the reporting of COVID-19 symptoms.

Outcomes of hospitalized COVID-19 patients in Canada: impact of ethnicity, migration status and country of birth

BACKGROUND

Ethnoracial groups in high-income countries have a 2-fold higher risk of SARS-CoV-2 infection, associated hospitalizations, and mortality than Whites. Migrants are an ethnoracial subset that may have worse COVID-19 outcomes due to additional barriers accessing care, but there are limited data on in-hospital outcomes. We aimed to disaggregate and compare COVID-19 associated hospital outcomes by ethnicity, immigrant status and region of birth.

METHODS

Adults with community-acquired SARS-CoV-2 infection, hospitalized March 1-June 30, 2020, at four hospitals in Montréal, Quebec, Canada, were included. Age, sex, socioeconomic status, comorbidities, migration status, region of birth, self-identified ethnicity [White, Black, Asian, Latino, Middle East/North African], intensive care unit (ICU) admissions and mortality were collected. Adjusted hazard ratios (aHR) for ICU admission and mortality by immigrant status, ethnicity and region of birth adjusted for age, sex, socioeconomic status and comorbidities were estimated using Fine and Gray competing risk models.

RESULTS

Of 1104 patients (median [IQR] age, 63.0 [51.0-76.0] years; 56% males), 57% were immigrants and 54% were White. Immigrants were slightly younger (62 vs 65 years; p = 0.050), had fewer comorbidities (1.0 vs 1.2; p < 0.001), similar crude ICU admissions rates (33.0% vs 28.2%) and lower mortality (13.3% vs 17.6%; p < 0.001) than Canadian-born. In adjusted models, Blacks (aHR 1.39, 95% confidence interval 1.05-1.83) and Asians (1.64, 1.15-2.34) were at higher risk of ICU admission than Whites, but there was significant heterogeneity within ethnic groups. Asians from Eastern Asia/Pacific (2.15, 1.42-3.24) but not Southern Asia (0.97, 0.49-1.93) and Caribbean Blacks (1.39, 1.02-1.89) but not SSA Blacks (1.37, 0.86-2.18) had a higher risk of ICU admission. Blacks had a higher risk of mortality (aHR 1.56, p = 0.049).

CONCLUSIONS

Data disaggregated by region of birth identified subgroups of immigrants at increased risk of COVID-19 ICU admission, providing more actionable data for health policymakers to address health inequities.

In-hospital outcomes of SARS-CoV-2-infected health care workers in the COVID-19 pandemic first wave, Quebec, Canada

Background

Health care workers (HCW), particularly immigrants and ethnic minorities are at increased risk for SARS-CoV-2 infection. Outcomes during a COVID-19 associated hospitalization are not well described among HCW. We aimed to describe the characteristics of HCW admitted with COVID-19 including immigrant status and ethnicity and the associated risk factors for Intensive Care unit (ICU) admission and death.

Methods

Adults with laboratory-confirmed community-acquired COVID-19 hospitalized from March 1 to June 30, 2020, at four tertiary-care hospitals in Montréal, Canada were included. Demographics, comorbidities, occupation, immigration status, country of birth, ethnicity, workplace exposures, and hospital outcomes (ICU admission and death) were obtained through a chart review and phone survey. A Fine and Gray competing risk proportional hazards model was used to estimate the risk of ICU admission among HCW stratified by immigrant status and region of birth.

Results

Among 1104 included persons, 150 (14%) were HCW, with a phone survey participation rate of 68%. HCWs were younger (50 vs 64 years; p<0.001), more likely to be female (61% vs 41%; p<0.001), migrants (68% vs 55%; p<0.01), non-White (65% vs 41%; p<0.001) and healthier (mean Charlson Comorbidity Index of 0.3 vs 1.2; p<0.001) compared to non-HCW. They were as likely to be admitted to the ICU (28% vs 31%; p = 0.40) but were less likely to die (4% vs. 17%; p<0.001). Immigrant HCW accounted for 68% of all HCW cases and, compared to Canadian HCW, were more likely to be personal support workers (PSW) (54% vs. 33%, p<0.01), to be Black (58% vs 4%) and to work in a Residential Care Facility (RCF) (59% vs 33%; p = 0.05). Most HCW believed that they were exposed at work, 55% did not always have access to personal protective equipment (PPE) and 40% did not receive COVID-19-specific Infection Control (IPAC) training.

Conclusion

Immigrant HCW were particularly exposed to COVID-19 infection in the first wave of the pandemic in Quebec. Despite being young and healthy, one third of all HCW required ICU admission, highlighting the importance of preventing workplace transmission through strong infection prevention and control measures, including high COVID-19 vaccination coverage.

"Bring the Hoses to Where the Fire Is!": Differential Impacts of Marginalization and Socioeconomic Status on COVID-19 Case Counts and Healthcare Costs

OBJECTIVES

Local health leaders and the Director General of the World Health Organization alike have observed that COVID-19 "does not discriminate." Nevertheless, the disproportionate representation of people of low socioeconomic status among those infected resembles discrimination. This population-based retrospective cohort study examined COVID-19 case counts and publicly funded healthcare costs in Ontario, Canada, with a focus on marginalization.

METHODS

Individuals with their first positive severe acute respiratory syndrome coronavirus 2 test from January 1, 2020 to June 30, 2020, were linked to administrative databases and matched to negative/untested controls. Mean net (COVID-19-attributable) costs were estimated for 30 days before and after diagnosis, and differences among strata of age, sex, comorbidity, and measures of marginalization were assessed using analysis of variance tests.

RESULTS

We included 28 893 COVID-19 cases (mean age 54 years, 56% female). Most cases remained in the community (20 545, 71.1%) or in long-term care facilities (4478, 15.5%), whereas 944 (3.3%) and 2926 (10.1%) were hospitalized, with and without intensive care unit, respectively. Case counts were skewed across marginalization strata with 2 to 7 times more cases in neighborhoods with low income, high material deprivation, and highest ethnic concentration. Mean net costs after diagnosis were higher for males ($4752 vs $2520 for females) and for cases with higher comorbidity ($1394-$7751) (both P < .001) but were similar across levels of most marginalization dimensions (range $3232-$3737, all P ≥ .19).

CONCLUSIONS

This study suggests that allocating resources unequally to marginalized individuals may improve equality in outcomes. It highlights the importance of reducing risk of COVID-19 infection among marginalized individuals to reduce overall costs and increase system capacity.

Intention to Receive a COVID-19 Vaccine by HIV Status Among a Population-Based Sample of Women and Gender Diverse Individuals in British Columbia, Canada

COVID-19 vaccination is recommended for people living with HIV (PLWH), among whom social inequities and co-morbidities may drive risks of COVID-19 infection and outcome severity. Among a provincial (British Columbia) sample, we determined the prevalence of COVID-19 vaccine intention by HIV status and assessed socio-demographic, vaccine hesitancy, and psychological predictors of vaccine intention. Individuals (25-69 years) recruited from province-wide research cohorts and the general public completed an online survey examining COVID-19 impacts (August/2020-March/2021). In an analysis restricted to women and gender diverse participants (n = 5588), we compared intention to receive a recommended COVID-19 vaccine (Very likely/Likely vs Neutral/Unlikely/Very Unlikely) by self-reported HIV status. Logistic regression models assessed the independent effect of HIV status and other factors on COVID-19 vaccine intention. Of 5588 participants, 69 (1.2%) were living with HIV, of whom 79.7% were on antiretroviral therapy. In bivariate analyses, intention to vaccinate was significantly lower among PLWH compared to participants not living with HIV (65.2% vs 79.6%; OR 0.44; 95%CI 0.32-0.60). However, this association was not statistically significant after adjustment for ethnicity, income, education, and essential worker status (aOR 0.85; 95%CI 0.48-1.55). Among PLWH, those with greater vaccine confidence, positive attitudes towards the COVID-19 vaccine, and more strongly influenced by direct and indirect social norms to vaccinate had significantly higher odds of vaccine intention. Tailored messaging is needed to build vaccine confidence, address questions about vaccine benefits, and support informed vaccination decision-making to promote COVID-19 vaccine uptake among women and gender diverse people living with HIV.

Clinical risk, sociodemographic factors, and SARS-CoV-2 infection over time in Ontario, Canada

We aimed to determine whether early public health interventions in 2020 mitigated the association of sociodemographic and clinical risk factors with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted a population-based cohort study of all adults in Ontario, Canada who underwent testing for SARS-CoV-2 through December 31, 2020. The outcome was laboratory-confirmed SARS-CoV-2 infection, determined by reverse transcription polymerase chain reaction testing. Adjusted odds ratios (ORs) were determined for sociodemographic and clinical risk factors before and after the first-wave peak of the pandemic to assess for changes in effect sizes. Among 3,167,753 community-dwelling individuals, 142,814 (4.5%) tested positive. The association between age and SARS-CoV-2 infection risk varied over time (P-interaction < 0.0001). Prior to the first-wave peak, SARS-CoV-2 infection increased with age whereas this association reversed thereafter. Risk factors that persisted included male sex, residing in lower income neighborhoods, residing in more racially/ethnically diverse communities, immigration to Canada, hypertension, and diabetes. While there was a reduction in infection rates after mid-April 2020, there was less impact in regions with higher racial/ethnic diversity. Immediately following the initial peak, individuals living in the most racially/ethnically diverse communities with 2, 3, or ≥ 4 risk factors had ORs of 1.89, 3.07, and 4.73-fold higher for SARS-CoV-2 infection compared to lower risk individuals in their community (all P < 0.0001). In the latter half of 2020, this disparity persisted with corresponding ORs of 1.66, 2.48, and 3.70-fold higher, respectively. In the least racially/ethnically diverse communities, there was little/no gradient in infection rates across risk strata. Further efforts are necessary to reduce the risk of SARS-CoV-2 infection among the highest risk individuals residing in the most racially/ethnically diverse communities.

Association between area-level material deprivation and incidence of hospitalization among children with SARS-CoV-2 in Montreal

Background

Although sociodemographic factors have been linked with SARS-CoV-2 infection and hospitalizations in adults, there are little data on the association between sociodemographic characteristics and SARS-CoV-2-related hospitalization in children. The objective of this study was to determine the association between area-level material deprivation and incidence of hospitalization with SARS-CoV-2 among children.

Methods

We conducted a retrospective cohort study of all children (0 to 17 years of age) with a PCR-confirmed SARS-CoV-2 infection March 1, 2020 through May 31, 2021 at a tertiary-care paediatric hospital, in Montreal, Canada. Data were collected through chart review and included age, sex, and postal code, allowing linkage to dissemination area-level material deprivation, measured with the Pampalon Material Deprivation Index (PMDI) quintiles. We examined the association between PMDI quintiles and hospitalization using Poisson regression.

Results

During the study period, 964 children had a positive PCR-confirmed SARS-CoV-2 test and 124 were hospitalized. Children living in the most deprived quintile of PMDI represented 40.7% of hospitalizations. Incidence rate ratio of hospitalization for this group compared to the most privileged quintile was 2.42 (95%CI: 1.33; 4.41).

Conclusion

Children living in the most materially deprived areas had more than twice the rate of hospitalizations for COVID-19 than children living in most privileged areas. Special efforts should be deployed to protect children who live in disadvantaged areas, especially pending vaccination of younger children.

L’association entre la défavorisation matérielle par quartier et l’incidence d’hospitalisation chez les enfants infectés par le SRAS-CoV-2 à Montréal

Historique

Même si les facteurs sociodémographiques sont liés à l’infection par le SRAS-CoV-2 et aux hospitalisations chez les adultes, peu de données portent sur l’association entre ces caractéristiques et les hospitalisations attribuables au SRAS-CoV-2 chez les enfants. La présente étude visait à déterminer l’association entre la défavorisation matérielle par quartier et l’incidence d’hospitalisations à cause du SRAS-CoV-2 chez les enfants.

Méthodologie

Les chercheurs ont réalisé une étude de cohorte rétrospective de tous les enfants (de 0 à 17 ans) atteints d’une infection par le SRAS-CoV-2 confirmée par un test d’amplification en chaîne par polymérase après transcription inverse (PCR) entre le 1^er mars et le 31 mai 2021 dans un hôpital pédiatrique de soins tertiaires de Montréal, au Canada. Ils ont colligé les données par examen des dossiers et ont inclus l’âge, le sexe et les codes postaux, afin de pouvoir lier la défavorisation matérielle à l’échelle de l’aire de diffusion, mesurée au moyen des quintiles de l’indice de défavorisation matérielle de Pampalon. Ils ont examiné l’association entre les quintiles de cet indice et les hospitalisations à l’aide de la régression de Poisson.

Résultats

Pendant la période de l’étude, 964 enfants ont reçu un résultat positif au SRAS-CoV-2 confirmé par un test PCR, et 124 d’entre eux ont été hospitalisés. Au total, 40,7 % des enfants hospitalisés habitaient dans le quintile le plus défavorisé d’après l’indice de défavorisation matérielle de Pampalon. Le rapport du taux d’incidence des hospitalisations dans ce groupe était de 2,42 (intervalle de confiance à 95 % : 1,33; 4,41) par rapport au quintile le plus privilégié.

Conclusion

Plus du double des enfants qui habitaient dans les quartiers les plus défavorisés sur le plan matériel étaient hospitalisés à cause de la COVID-19 par rapport à ceux qui habitaient dans les quartiers les plus privilégiés. Il faudrait déployer des efforts particuliers pour protéger les enfants qui habitent dans des quartiers défavorisés, particulièrement dans l’attente de la vaccination des plus jeunes.

Association between long-term exposure to ambient air pollution and COVID-19 severity: a prospective cohort study

Background:

The tremendous global health burden related to COVID-19 means that identifying determinants of COVID-19 severity is important for prevention and intervention. We aimed to explore long-term exposure to ambient air pollution as a potential contributor to COVID-19 severity, given its known impact on the respiratory system.

Methods:

We used a cohort of all people with confirmed SARS-CoV-2 infection, aged 20 years and older and not residing in a long-term care facility in Ontario, Canada, during 2020. We evaluated the association between long-term exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂) and ground-level ozone (O₃), and risk of COVID-19-related hospital admission, intensive care unit (ICU) admission and death. We ascertained individuals’ long-term exposures to each air pollutant based on their residence from 2015 to 2019. We used logistic regression and adjusted for confounders and selection bias using various individual and contextual covariates obtained through data linkage.

Results:

Among the 151 105 people with confirmed SARS-CoV-2 infection in Ontario in 2020, we observed 8630 hospital admissions, 1912 ICU admissions and 2137 deaths related to COVID-19. For each interquartile range increase in exposure to PM_2.5 (1.70 μg/m³), we estimated odds ratios of 1.06 (95% confidence interval [CI] 1.01–1.12), 1.09 (95% CI 0.98–1.21) and 1.00 (95% CI 0.90–1.11) for hospital admission, ICU admission and death, respectively. Estimates were smaller for NO₂. We also estimated odds ratios of 1.15 (95% CI 1.06–1.23), 1.30 (95% CI 1.12–1.50) and 1.18 (95% CI 1.02–1.36) per interquartile range increase of 5.14 ppb in O₃ for hospital admission, ICU admission and death, respectively.

Interpretation:

Chronic exposure to air pollution may contribute to severe outcomes after SARS-CoV-2 infection, particularly exposure to O₃.

Evaluation of the Real-World Effectiveness of Vaccines against COVID-19 at a Local Level: Protocol for a Test-Negative Case-Control Study

Vaccines against COVID-19 approved for use in the EU/EEA have been shown to be highly effective against wild-type SARS-CoV-2. However, their effectiveness against new variants may be reduced. This study aims to evaluate the effectiveness of vaccines against COVID-19 in the prevention of symptomatic and severe disease, during pre- and post-omicron phases. Individuals who sought treatment at the emergency department of a Portuguese hospital with COVID-19-like disease and were tested for SARS-CoV-2 are the subjects of the study. Patients who received a positive result are considered cases, while those with negative results are the controls. The test-negative case–control method is one of the study designs recommended by WHO to estimate the effectiveness of vaccines against COVID-19. The main advantage of this design is that it controls for the healthcare seeking bias, commonly present in traditional cohort and case–control designs. This study may have broad implications for understanding the real-world performance of the COVID-19 vaccines at the local level, which may play a key role in promoting adherence to vaccination. Moreover, this study may contribute to inform decisions regarding booster doses and variant-specific vaccine formulations leading to the control of this and future pandemics.

A compelling demonstration of why traditional statistical regression models cannot be used to identify risk factors from case data on infectious diseases: a simulation study

BACKGROUND

Regression models are often used to explain the relative risk of infectious diseases among groups. For example, overrepresentation of immigrants among COVID-19 cases has been found in multiple countries. Several studies apply regression models to investigate whether different risk factors can explain this overrepresentation among immigrants without considering dependence between the cases.

METHODS

We study the appropriateness of traditional statistical regression methods for identifying risk factors for infectious diseases, by a simulation study. We model infectious disease spread by a simple, population-structured version of an SIR (susceptible-infected-recovered)-model, which is one of the most famous and well-established models for infectious disease spread. The population is thus divided into different sub-groups. We vary the contact structure between the sub-groups of the population. We analyse the relation between individual-level risk of infection and group-level relative risk. We analyse whether Poisson regression estimators can capture the true, underlying parameters of transmission. We assess both the quantitative and qualitative accuracy of the estimated regression coefficients.

RESULTS

We illustrate that there is no clear relationship between differences in individual characteristics and group-level overrepresentation -small differences on the individual level can result in arbitrarily high overrepresentation. We demonstrate that individual risk of infection cannot be properly defined without simultaneous specification of the infection level of the population. We argue that the estimated regression coefficients are not interpretable and show that it is not possible to adjust for other variables by standard regression methods. Finally, we illustrate that regression models can result in the significance of variables unrelated to infection risk in the constructed simulation example (e.g. ethnicity), particularly when a large proportion of contacts is within the same group.

CONCLUSIONS

Traditional regression models which are valid for modelling risk between groups for non-communicable diseases are not valid for infectious diseases. By applying such methods to identify risk factors of infectious diseases, one risks ending up with wrong conclusions. Output from such analyses should therefore be treated with great caution.

Stringency of containment and closures on the growth of SARS-CoV-2 in Canada prior to accelerated vaccine roll-out

BACKGROUND

Many studies have examined the effectiveness of non-pharmaceutical interventions (NPIs) on SARS-CoV-2 transmission worldwide. However, less attention has been devoted to understanding the limits of NPIs across the course of the pandemic and along a continuum of their stringency. In this study, we explore the relationship between the growth of SARS-CoV-2 cases and an NPI stringency index across Canada before the accelerated vaccine roll-out.

METHODS

We conducted an ecological time-series study of daily SARS-CoV-2 case growth in Canada from February 2020 to February 2021. Our outcome was a back-projected version of the daily growth ratio in a stringency period (i.e., a 10-point range of the stringency index) relative to the last day of the previous period. We examined the trends in case growth using a linear mixed-effects model accounting for stringency period, province, and mobility in public domains.

RESULTS

Case growth declined rapidly by 20-60% and plateaued within the first month of the first wave, irrespective of the starting values of the stringency index. When stringency periods increased, changes in case growth were not immediate and were faster in the first wave than in the second. In the first wave, the largest decreasing trends from our mixed effects model occurred in both early and late stringency periods, depending on the province, at a geometric mean index value of 30⋅1 out of 100. When compared with the first wave, the stringency periods in the second wave possessed little association with case growth.

CONCLUSIONS

The minimal association in the first wave, and the lack thereof in the second, is compatible with the hypothesis that NPIs do not, per se, lead to a decline in case growth. Instead, the correlations we observed might be better explained by a combination of underlying behaviors of the populations in each province and the natural dynamics of SARS-CoV-2. Although there exist alternative explanations for the equivocal relationship between NPIs and case growth, the onus of providing evidence shifts to demonstrating how NPIs can consistently have flat association, despite incrementally high stringency.

Risk of COVID-19 Infections and of Severe Complications Among Survivors of Childhood, Adolescent, and Young Adult Cancer: A Population-Based Study in Ontario, Canada

PURPOSE

Survivors of childhood, adolescent, and young adult cancer are at risk of late effects, including pulmonary and infectious complications. Whether survivors are at increased risk of COVID-19 infection and severe complications is unknown.

METHODS

Population-based registries in Ontario, Canada, identified all 5-year survivors of childhood cancer diagnosed age 0-17 years between 1985 and 2014, and of six common adolescent and young adult cancers diagnosed age 15-21 years between 1992 and 2012. Each survivor alive on January 1, 2020, was randomly matched by birth year, sex, and residence to 10 cancer-free population controls. Individuals were linked to population-based laboratory and health care databases to identify COVID-19 tests, vaccinations, infections, and severe outcomes (emergency department [ED] visits, hospitalizations, intensive care unit admissions, and death within 60 days). Demographic, disease, and treatment-related variables were examined as possible predictors of outcomes.

RESULTS

Twelve thousand four hundred ten survivors were matched to 124,100 controls. Survivors were not at increased risk of receiving a positive COVID-19 test (386 [3.1%] v 3,946 [3.2%]; P = .68) and were more likely to be fully vaccinated (hazard ratio, 1.23; 95 CI, 1.20 to 1.37). No increase in risk among survivors was seen in emergency department visits (adjusted odds ratio, 1.2; 95 CI, 0.9 to 1.6; P = .19) or hospitalization (adjusted odds ratio, 1.8; 95 CI, 1.0 to 3.5; P = .07). No survivor experienced intensive care unit admission or died after COVID-19 infection. Pulmonary radiation or chemotherapies associated with pulmonary toxicity were not associated with increased risk.

CONCLUSION

Cancer survivors were not at increased risk of COVID-19 infections or severe sequelae. These results can inform risk-counseling of survivors and their caregivers. Further study is warranted to determine risk in older survivors, specific subsets of survivors, and that associated with novel COVID-19 variants.

Screening Large Population Health Databases for Potential COVID-19 Therapeutics: A Pharmacopeia-Wide Association Study (PWAS) of Commonly Prescribed Medications

Background

For both the current and future pandemics, there is a need for high-throughput drug screening methods to identify existing drugs with potential preventative and/or therapeutic activity. Epidemiologic studies could complement lab-focused efforts to identify possible therapeutic agents.

Methods

We performed a pharmacopeia-wide association study (PWAS) to identify commonly prescribed medications and medication classes that are associated with the detection of SARS-CoV-2 in older individuals (&gt;65 years) in long-term care homes (LTCH) and the community, between January 15 th, 2020 and December 31 st, 2020, across the province of Ontario, Canada.

Results

26,121 cases and 2,369,020 controls from LTCH and the community were included in this analysis. Many of the drugs and drug classes evaluated did not yield significant associations with SARS-CoV-2 detection. However, some drugs and drug classes appeared significantly associated with reduced SARS-CoV-2 detection, including cardioprotective drug classes such as statins (weighted OR 0.91, standard p-value &lt;0.01, adjusted p-value &lt;0.01) and beta-blockers (weighted OR 0.87, standard p-value &lt;0.01, adjusted p-value 0.01), along with individual agents ranging from levetiracetam (weighted OR 0.70, standard p-value &lt;0.01, adjusted p-value &lt;0.01) to fluoxetine (weighted OR 0.86, standard p-value 0.013, adjusted p-value 0.198) to digoxin (weighted OR 0.89, standard p-value &lt;0.01, adjusted p-value 0.02).

Conclusions

Using this epidemiologic approach which can be applied to current and future pandemics we have identified a variety of target drugs and drug classes that could offer therapeutic benefit in COVID-19 and may warrant further validation. Some of these agents (e.g. fluoxetine) have already been identified for their therapeutic potential.

Effectiveness of COVID-19 vaccines against symptomatic SARS-CoV-2 infection and severe outcomes with variants of concern in Ontario

SARS-CoV-2 variants of concern (VOC) are more transmissible and may have the potential for increased disease severity and decreased vaccine effectiveness. We estimated the effectiveness of BNT162b2 (Pfizer-BioNTech Comirnaty), mRNA-1273 (Moderna Spikevax) and ChAdOx1 (AstraZeneca Vaxzevria) vaccines against symptomatic SARS-CoV-2 infection and COVID-19 hospitalization or death caused by the Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1) and Delta (B.1.617.2) VOC in Ontario, Canada, using a test-negative design study. We identified 682,071 symptomatic community-dwelling individuals who were tested for SARS-CoV-2, and 15,269 individuals with a COVID-19 hospitalization or death. Effectiveness against symptomatic infection ≥7 d after two doses was 89-92% against Alpha, 87% against Beta, 88% against Gamma, 82-89% against Beta/Gamma and 87-95% against Delta across vaccine products. The corresponding estimates ≥14 d after one dose were lower. Effectiveness estimates against hospitalization or death were similar to or higher than against symptomatic infection. Effectiveness against symptomatic infection was generally lower for older adults (≥60 years) than for younger adults (<60 years) for most of the VOC-vaccine combinations. Our findings suggest that jurisdictions facing vaccine supply constraints may benefit from delaying the second dose in younger individuals to more rapidly achieve greater overall population protection; however, older adults would likely benefit most from minimizing the delay in receiving the second dose to achieve adequate protection against VOC.

Using Andersen's model of health care utilization to assess factors associated with COVID-19 testing among adults in nine low-and middle-income countries: an online survey

Background

This study aimed to investigate, using Andersen’s model of health care utilization, factors associated with COVID-19 testing among adults in nine low- and middle- income countries.

Methods

In between 10 December 2020 and 9 February 2021, an online survey was organized in nine low- and middle-income countries. In total 10,183 adults (median age 45 years, interquartile range 33–57 years, range 18–93 years), including 6470 from Brazil, 1738 Malaysia, 1124 Thailand, 230 Bangladesh, 219 DR Congo, 159 Benin, 107 Uganda, 81 Malawi and 55 from Mali participated in the study. COVID-19 testing/infection status was assessed by self-report.

Results

Of the 10,183 participants, 40.3% had ever tested for COVID-19, 7.3% tested positive, and 33.0% tested negative. In an adjusted logistic regression model, predisposing factors (residing in Brazil, postgraduate education), enabling/disabling factors (urban residence, higher perceived economic status, being a student or worker in the health care sector, and moderate or severe psychological distress), and need factors (having at least one chronic condition) increased the odds of COVID-19 testing. Among those who were tested, participants residing in Bangladesh, those who had moderate to severe psychological distress were positively associated with COVID-19 positive diagnosis. Participants who are residing in Malaysia and Thailand, and those who had higher education were negatively associated with a COVID-19 positive diagnosis. Considering all participants, higher perceived economic status, being a student or worker in the health sector, and moderate or severe psychological distress were positively associated with a COVID-19 positive diagnosis, and residing in Malaysia, Thailand or five African countries was negatively associated with a COVID-19 positive diagnosis.

Conclusion

A high rate of COVID-19 testing among adults was reported in nine low-and middle-income countries. However, access to testing needs to be increased in Africa. Moreover, COVID-19 testing programmes need to target persons of lower economic status and education level who are less tested but most at risk for COVID-19 infection.

Geographic concentration of SARS-CoV-2 cases by social determinants of health in metropolitan areas in Canada: a cross-sectional study

Background:

Understanding inequalities in SARS-CoV-2 transmission associated with the social determinants of health could help the development of effective mitigation strategies that are responsive to local transmission dynamics. This study aims to quantify social determinants of geographic concentration of SARS-CoV-2 cases across 16 census metropolitan areas (hereafter, cities) in 4 Canadian provinces, British Columbia, Manitoba, Ontario and Quebec.

Methods:

We used surveillance data on confirmed SARS-CoV-2 cases and census data for social determinants at the level of the dissemination area (DA). We calculated Gini coefficients to determine the overall geographic heterogeneity of confirmed cases of SARS-CoV-2 in each city, and calculated Gini covariance coefficients to determine each city’s heterogeneity by each social determinant (income, education, housing density and proportions of visible minorities, recent immigrants and essential workers). We visualized heterogeneity using Lorenz (concentration) curves.

Results:

We observed geographic concentration of SARS-CoV-2 cases in cities, as half of the cumulative cases were concentrated in DAs containing 21%–35% of their population, with the greatest geographic heterogeneity in Ontario cities (Gini coefficients 0.32–0.47), followed by British Columbia (0.23–0.36), Manitoba (0.32) and Quebec (0.28–0.37). Cases were disproportionately concentrated in areas with lower income and educational attainment, and in areas with a higher proportion of visible minorities, recent immigrants, high-density housing and essential workers. Although a consistent feature across cities was concentration by the proportion of visible minorities, the magnitude of concentration by social determinant varied across cities.

Interpretation:

Geographic concentration of SARS-CoV-2 cases was observed in all of the included cities, but the pattern by social determinants varied. Geographically prioritized allocation of resources and services should be tailored to the local drivers of inequalities in transmission in response to the resurgence of SARS-CoV-2.

Factors associated with SARS-CoV-2 test positivity in long-term care homes: A population-based cohort analysis using machine learning

BACKGROUND

SARS-Cov-2 infection rates are high among residents of long-term care (LTC) homes. We used machine learning to identify resident and community characteristics predictive of SARS-Cov-2 infection.

METHODS

We linked 26 population-based health and administrative databases to identify the population of all LTC residents tested for SARS-Cov-2 infection in Ontario, Canada. Using ensemble-based algorithms, we examined 484 factors, including individual-level demographics, healthcare use, comorbidities, functional status, and laboratory results; and community-level characteristics to identify factors predictive of infection. Analyses were performed separately for January to April (early wave 1) and May to August (late wave 1).

FINDINGS

Among 80,784 LTC residents, 64,757 (80.2%) were tested for SARS-Cov-2 (median age 86 (78-91) years, 30.6% male), of whom 10.2% of 33,519 and 5.2% of 31,238 tested positive in early and late wave 1, respectively. In the late phase (when restriction of visitors, closure of communal spaces, and universal masking in LTC were routine), regional-level characteristics comprised 33 of the top 50 factors associated with testing positive, while laboratory values and comorbidities were also predictive. The c-index of the final model was 0.934, and sensitivity was 0.887. In the highest versus lowest risk quartiles, the odds ratio for infection was 114.3 (95% CI 38.6-557.3). LTC-related geographic variations existed in the distribution of observed infection rates and the proportion of residents at highest risk.

INTERPRETATION

Machine learning informed evaluation of predicted and observed risks of SARS-CoV-2 infection at the resident and LTC levels, and may inform initiatives to improve care quality in this setting.

FUNDING

Funded by a Canadian Institutes of Health Research, COVID-19 Rapid Research Funding Opportunity grant (# VR4 172736) and a Peter Munk Cardiac Centre Innovation Grant. Dr. D. Lee is the Ted Rogers Chair in Heart Function Outcomes, University Health Network, University of Toronto. Dr. Austin is supported by a Mid-Career investigator award from the Heart and Stroke Foundation. Dr. McAlister is supported by an Alberta Health Services Chair in Cardiovascular Outcomes Research. Dr. Kaul is the CIHR Sex and Gender Science Chair and the Heart & Stroke Chair in Cardiovascular Research. Dr. Rochon holds the RTO/ERO Chair in Geriatric Medicine from the University of Toronto. Dr. B. Wang holds a CIFAR AI chair at the Vector Institute.

Clinical characteristics and outcomes of multiple sclerosis patients with COVID-19 in Toronto, Canada

Objective

To report clinical characteristics and outcomes of people with multiple sclerosis (PwMS) who developed COVID-19 infection in Toronto, Canada.

Methods

Descriptive, retrospective, single-center study that included all known PwMS at the St. Michael's Hospital MS Clinic who had PCR-confirmed COVID-19 infection between March 2020 and May 2021.

Results

Of 7000 PwMS in our clinic, 80 (1.1%) tested positive for SARS-CoV-2. Fifty-four (67.5%) were on disease-modifying therapy (DMT) without over-representation of any single treatment. Seventy-one patients (88.8%) had mild symptoms, but nine (11.3%) were hospitalized and one 70-year-old male patient not on treatment died. Of those hospitalized, one-third were treated with ocrelizumab.

Conclusion

In Toronto, PwMS did not appear to have higher prevalence of COVID-19 infection compared to the general population, but disease severity may be affected by DMT use. Our findings add to the accumulating global data regarding COVID-19 infection in PwMS.

Increasing concentration of COVID-19 by socioeconomic determinants and geography in Toronto, Canada: an observational study

BACKGROUND

Inequities in the burden of COVID-19 were observed early in Canada and around the world, suggesting economically marginalized communities faced disproportionate risks. However, there has been limited systematic assessment of how heterogeneity in risks has evolved in large urban centers over time.

PURPOSE

To address this gap, we quantified the magnitude of risk heterogeneity in Toronto, Ontario from January to November 2020 using a retrospective, population-based observational study using surveillance data.

METHODS

We generated epidemic curves by social determinants of health (SDOH) and crude Lorenz curves by neighbourhoods to visualize inequities in the distribution of COVID-19 and estimated Gini coefficients. We examined the correlation between SDOH using Pearson-correlation coefficients.

RESULTS

Gini coefficient of cumulative cases by population size was 0.41 (95% confidence interval [CI]:0.36-0.47) and estimated for: household income (0.20, 95%CI: 0.14-0.28); visible minority (0.21, 95%CI:0.16-0.28); recent immigration (0.12, 95%CI:0.09-0.16); suitable housing (0.21, 95%CI:0.14-0.30); multigenerational households (0.19, 95%CI:0.15-0.23); and essential workers (0.28, 95%CI:0.23-0.34).

CONCLUSIONS

There was rapid epidemiologic transition from higher- to lower-income neighborhoods with Lorenz curve transitioning from below to above the line of equality across SDOH. Moving forward necessitates integrating programs and policies addressing socioeconomic inequities and structural racism into COVID-19 prevention and vaccination programs.

Neighbourhood-level socio-demographic characteristics and risk of COVID-19 incidence and mortality in Ontario, Canada: A population-based study

OBJECTIVES

We aimed to estimate associations between COVID-19 incidence and mortality with neighbourhood-level immigration, race, housing, and socio-economic characteristics.

METHODS

We conducted a population-based study of 28,808 COVID-19 cases in the provincial reportable infectious disease surveillance systems (Public Health Case and Contact Management System) which includes all known COVID-19 infections and deaths from Ontario, Canada reported between January 23, 2020 and July 28, 2020. Residents of congregate settings, Indigenous communities living on reserves or small neighbourhoods with populations <1,000 were excluded. Comparing neighbourhoods in the 90th to the 10th percentiles of socio-demographic characteristics, we estimated the associations between 18 neighbourhood-level measures of immigration, race, housing and socio-economic characteristics and COVID-19 incidence and mortality using Poisson generalized linear mixed models.

RESULTS

Neighbourhoods with the highest proportion of immigrants (relative risk (RR): 4.0, 95%CI:3.5-4.5) and visible minority residents (RR: 3.3, 95%CI:2.9-3.7) showed the strongest association with COVID-19 incidence in adjusted models. Among individual race groups, COVID-19 incidence was highest among neighbourhoods with the high proportions of Black (RR: 2.4, 95%CI:2.2-2.6), South Asian (RR: 1.9, 95%CI:1.8-2.1), Latin American (RR: 1.8, 95%CI:1.6-2.0) and Middle Eastern (RR: 1.2, 95%CI:1.1-1.3) residents. Neighbourhoods with the highest average household size (RR: 1.9, 95%CI:1.7-2.1), proportion of multigenerational families (RR: 1.8, 95%CI:1.7-2.0) and unsuitably crowded housing (RR: 2.1, 95%CI:2.0-2.3) were associated with COVID-19 incidence. Neighbourhoods with the highest proportion of residents with less than high school education (RR: 1.6, 95%CI:1.4-1.8), low income (RR: 1.4, 95%CI:1.2-1.5) and unaffordable housing (RR: 1.6, 95%CI:1.4-1.8) were associated with COVID-19 incidence. Similar inequities were observed across neighbourhood-level sociodemographic characteristics and COVID-19 mortality.

CONCLUSIONS

Neighbourhood-level inequities in COVID-19 incidence and mortality were observed in Ontario, with excess burden experienced in neighbourhoods with a higher proportion of immigrants, racialized populations, large households and low socio-economic status.

The effect of race, socioeconomic status, and comorbidity on patients afflicted with COVID 19: A Local Perspective

PURPOSE

The aim of this study is to further examine the associations of race, socioeconomic factors, and comorbidity with COVID-19 health outcomes.

METHODS

This is a retrospective cohort study of 309 PCR confirmed COVID-19 positive adults who presented to Tulane Medical Center in New Orleans, LA, from March 9 to May 29, 2020. The primary outcomes investigated were need for invasive mechanical ventilation (IMV) and in-hospital mortality. A multivariate analysis was performed to determine socioeconomic and medical risk factors for IMV and in-hospital mortality.

RESULTS

Compared to white patients, Black patients were more likely to present younger, female, obese, unemployed, and underinsured. However, when controlled for common risk factors, Black and white patients had similar risk for IMV and mortality. Increased age (≥65 years), obesity, and increased comorbidity were associated with increased risk for IMV and mortality.

CONCLUSIONS

Race and socioeconomic factors may increase risk for COVID-19 infection but did not affect health outcomes within the hospital setting. Therefore, the higher rates of COVID-19 infection and mortality in vulnerable populations may be better explained by lower socioeconomic status, with subsequent higher comorbidity, in these populations. Community health initiatives should be prioritized in response to the COVID-19 pandemic.

The income gradient in COVID-19 mortality and hospitalisation: An observational study with social security administrative records in Mexico

BACKGROUND

The COVID-19 pandemic revealed large structural inequalities that led to disparities in health outcomes related to socioeconomic status. So far, most of the evidence is based on aggregated data or simulations with individual data, which point to various possible mechanisms behind the association. To date, there have been no studies regarding an income gradient in COVID-19 mortality based on individual-level data and adjusting for comorbidities or access to healthcare.

METHODS

In this paper, we use linked employee-patient data for patients tested for COVID-19 at the Mexican Institute of Social Security. We estimate the association of the probability of dying with income centiles, using a probit estimation and adjusting for COVID-19 diagnosis, sociodemographic variables, and comorbidities.

FINDINGS

After controlling for all these variables, we find that persons in the lowest income decile still had a probability of dying from COVID-19 five times greater than those at the top decile.

INTERPRETATION

Our results imply that the association between income and COVID outcomes is not explained by the prevalence of comorbidities or by a lack of access to healthcare among the low-income population.

FUNDING

This study was not supported by any external funding source.

Mental Health and Substance Use Associated with Hospitalization among People with COVID-19: A Population-Based Cohort Study

This study identified factors associated with hospital admission among people with laboratory-diagnosed COVID-19 cases in British Columbia. The study used data from the BC COVID-19 Cohort, which integrates data on all COVID-19 cases with data on hospitalizations, medical visits, emergency room visits, prescription drugs, chronic conditions and deaths. The analysis included all laboratory-diagnosed COVID-19 cases in British Columbia to 15 January 2021. We evaluated factors associated with hospital admission using multivariable Poisson regression analysis with robust error variance. Of the 56,874 COVID-19 cases included in the analysis, 2298 were hospitalized. Factors associated with increased hospitalization risk were as follows: male sex (adjusted risk ratio (aRR) = 1.27; 95% CI = 1.17–1.37), older age (p-trend < 0.0001 across age groups increasing hospitalization risk with increasing age [aRR 30–39 years = 3.06; 95% CI = 2.32–4.03, to aRR 80+ years = 43.68; 95% CI = 33.41–57.10 compared to 20–29 years-old]), asthma (aRR = 1.15; 95% CI = 1.04–1.26), cancer (aRR = 1.19; 95% CI = 1.09–1.29), chronic kidney disease (aRR = 1.32; 95% CI = 1.19–1.47), diabetes (treated without insulin aRR = 1.13; 95% CI = 1.03–1.25, requiring insulin aRR = 5.05; 95% CI = 4.43–5.76), hypertension (aRR = 1.19; 95% CI = 1.08–1.31), injection drug use (aRR = 2.51; 95% CI = 2.14–2.95), intellectual and developmental disabilities (aRR = 1.67; 95% CI = 1.05–2.66), problematic alcohol use (aRR = 1.63; 95% CI = 1.43–1.85), immunosuppression (aRR = 1.29; 95% CI = 1.09–1.53), and schizophrenia and psychotic disorders (aRR = 1.49; 95% CI = 1.23–1.82). In an analysis restricted to women of reproductive age, pregnancy (aRR = 2.69; 95% CI = 1.42–5.07) was associated with increased risk of hospital admission. Older age, male sex, substance use, intellectual and developmental disability, chronic comorbidities, and pregnancy increase the risk of COVID-19-related hospitalization.

Education Attainment, Intelligence and COVID-19: A Mendelian Randomization Study

Background: Evidence of socioeconomic inequality in COVID-19-related outcomes is emerging, with a higher risk of infection and mortality observed among individuals with lower education attainment. We aimed to evaluate the potential interventions against COVID-19 from the socioeconomic perspective, including improvement in education and intelligence. Methods: With a two-sample Mendelian randomization approach using summary statistics from the largest genome-wide association meta-analysis, univariable analysis was adopted to evaluate the total causal effects of genetically determined education attainment and intelligence on COVID-19 outcomes. Multivariable analysis was performed to dissect the potential mechanisms. Results: Genetic predisposition to higher education attainment by 1 SD (4.2 years) was independently associated with reduced risk of COVID-19 severity (OR = 0.508 [95% CI: 0.417–0.617]; p < 0.001). Genetically higher education attainment also lowered the risk of COVID-19 hospitalization (0.685 [0.593–0.791]; p < 0.001), but the association was attenuated after adjustment for beta estimates of intelligence in multivariable analysis. Genetically higher intelligence was associated with reduced risk of COVID-19 hospitalization (0.780 [0.655–0.930]; p = 0.006), with attenuation of association after adjustment for education attainment. Null association was observed for genetically determined education attainment and intelligence with SARS-CoV-2 infection. Conclusion: Education may act independently and jointly with intelligence in improving the COVID-19 outcomes. Improving education may potentially alleviate the COVID-19-related health inequality.

Risk stratification for COVID-19 hospitalization: a multivariable model based on gradient-boosting decision trees

BACKGROUND

The COVID-19 pandemic has led to an increased demand for health care resources and, in some cases, shortage of medical equipment and staff. Our objective was to develop and validate a multivariable model to predict risk of hospitalization for patients infected with SARS-CoV-2.

METHODS

We used routinely collected health records in a patient cohort to develop and validate our prediction model. This cohort included adult patients (age ≥ 18 yr) from Ontario, Canada, who tested positive for SARS-CoV-2 ribonucleic acid by polymerase chain reaction between Feb. 2 and Oct. 5, 2020, and were followed up through Nov. 5, 2020. Patients living in long-term care facilities were excluded, as they were all assumed to be at high risk of hospitalization for COVID-19. Risk of hospitalization within 30 days of diagnosis of SARS-CoV-2 infection was estimated via gradient-boosting decision trees, and variable importance examined via Shapley values. We built a gradient-boosting model using the Extreme Gradient Boosting (XGBoost) algorithm and compared its performance against 4 empirical rules commonly used for risk stratifications based on age and number of comorbidities.

RESULTS

The cohort included 36 323 patients with 2583 hospitalizations (7.1%). Hospitalized patients had a higher median age (64 yr v. 43 yr), were more likely to be male (56.3% v. 47.3%) and had a higher median number of comorbidities (3, interquartile range [IQR] 2-6 v. 1, IQR 0-3) than nonhospitalized patients. Patients were split into development (n = 29 058, 80.0%) and held-out validation (n = 7265, 20.0%) cohorts. The gradient-boosting model achieved high discrimination (development cohort: area under the receiver operating characteristic curve across the 5 folds of 0.852; validation cohort: 0.8475) and strong calibration (slope = 1.01, intercept = -0.01). The patients who scored at the top 10% captured 47.4% of hospitalizations, and those who scored at the top 30% captured 80.6%.

INTERPRETATION

We developed and validated an accurate risk stratification model using routinely collected health administrative data. We envision that modelling such risk stratification based on routinely collected health data could support management of COVID-19 on a population health level.

Effectiveness of BNT162b2 and mRNA-1273 covid-19 vaccines against symptomatic SARS-CoV-2 infection and severe covid-19 outcomes in Ontario, Canada: test negative design study

OBJECTIVE

To estimate the effectiveness of mRNA covid-19 vaccines against symptomatic infection and severe outcomes (hospital admission or death).

DESIGN

Test negative design study.

SETTING

Ontario, Canada between 14 December 2020 and 19 April 2021.

PARTICIPANTS

324 033 community dwelling people aged ≥16 years who had symptoms of covid-19 and were tested for SARS-CoV-2.

INTERVENTIONS

BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine.

MAIN OUTCOME MEASURES

Laboratory confirmed SARS-CoV-2 by reverse transcription polymerase chain reaction (RT-PCR) and hospital admissions and deaths associated with SARS-CoV-2 infection. Multivariable logistic regression was adjusted for personal and clinical characteristics associated with SARS-CoV-2 and vaccine receipt to estimate vaccine effectiveness against symptomatic infection and severe outcomes.

RESULTS

Of 324 033 people with symptoms, 53 270 (16.4%) were positive for SARS-CoV-2 and 21 272 (6.6%) received at least one dose of vaccine. Among participants who tested positive, 2479 (4.7%) were admitted to hospital or died. Vaccine effectiveness against symptomatic infection observed ≥14 days after one dose was 60% (95% confidence interval 57% to 64%), increasing from 48% (41% to 54%) at 14-20 days after one dose to 71% (63% to 78%) at 35-41 days. Vaccine effectiveness observed ≥7 days after two doses was 91% (89% to 93%). Vaccine effectiveness against hospital admission or death observed ≥14 days after one dose was 70% (60% to 77%), increasing from 62% (44% to 75%) at 14-20 days to 91% (73% to 97%) at ≥35 days, whereas vaccine effectiveness observed ≥7 days after two doses was 98% (88% to 100%). For adults aged ≥70 years, vaccine effectiveness estimates were observed to be lower for intervals shortly after one dose but were comparable to those for younger people for all intervals after 28 days. After two doses, high vaccine effectiveness was observed against variants with the E484K mutation.

CONCLUSIONS

Two doses of mRNA covid-19 vaccines were observed to be highly effective against symptomatic infection and severe outcomes. Vaccine effectiveness of one dose was observed to be lower, particularly for older adults shortly after the first dose.

Update on the management of multiple sclerosis during the COVID-19 pandemic and post pandemic: An international consensus statement

In this consensus statement, we provide updated recommendations on multiple sclerosis (MS) management during the COVID-19 crisis and the post-pandemic period applicable to neurology services around the world. Statements/recommendations were generated based on available literature and the experience of 13 MS expert panelists using a modified Delphi approach online. The statements/recommendations give advice regarding implementation of telemedicine; use of disease-modifying therapies and management of MS relapses; management of people with MS at highest risk from COVID-19; management of radiological monitoring; use of remote pharmacovigilance; impact on MS research; implications for lowest income settings, and other key issues.

Prevalence of and factors associated with COVID-19 diagnosis in symptomatic patients followed in general practices in Germany between March 2020 and March 2021

Aims

This study aimed to investigate the prevalence of and the factors associated with the diagnosis of coronavirus disease 2019 (COVID-19) in symptomatic patients followed in general practices in Germany between March 2020 and March 2021.

Methods

Symptomatic patients tested for COVID-19 and followed in one of 962 general practices in Germany from March 2020 to March 2021 were included in this study. Covariates included sex, age, and comorbidities present in at least 3% of the population. The association between these factors and the diagnosis of COVID-19 was analyzed using an adjusted logistic regression model.

Results

A total of 301,290 patients tested for COVID-19 were included in this study (54.7% women; mean [SD] age 44.6 [18.5] years). The prevalence of COVID-19 was 13.8% in this sample. Male sex and older age were positively and significantly associated with COVID-19. In terms of comorbidities, the strongest positive associations with COVID-19 were observed for cardiac arrhythmias, depression, and obesity. There was also a negative relationship between the odds of being diagnosed with COVID-19 and several conditions such as chronic sinusitis, asthma, and anxiety disorders.

Conclusions

Approximately 14% of symptomatic patients tested for COVID-19 were diagnosed with COVID-19 in German general practices from March 2020 to March 2021.