Acute health care use among children during the first 2.5 years of the COVID-19 pandemic in Ontario, Canada: a population-based repeated cross-sectional study.

BACKGROUND: The effects of the decline in health care use at the start of the COVID-19 pandemic on the health of children are unclear. We sought to estimate changes in rates of severe and potentially preventable health outcomes among children during the pandemic. METHODS: We conducted a repeated cross-sectional study of children aged 0-17 years using linked population health administrative and disease registry data from January 2017 through August 2022 in Ontario, Canada. We compared observed rates of emergency department visits and hospital admissions during the pandemic to predicted rates based on the 3 years preceding the pandemic. We evaluated outcomes among children and neonates overall, among children with chronic health conditions and among children with specific diseases sensitive to delays in care. RESULTS: All acute care use for children decreased immediately at the onset of the pandemic, reaching its lowest rate in April 2020 for emergency department visits (adjusted relative rate [RR] 0.28, 95% confidence interval [CI] 0.28-0.29) and hospital admissions (adjusted RR 0.43, 95% CI 0.42-0.44). These decreases were sustained until September 2021 and May 2022, respectively. During the pandemic overall, rates of all-cause mortality, admissions for ambulatory care-sensitive conditions, newborn readmissions or emergency department visits or hospital admissions among children with chronic health conditions did not exceed predicted rates. However, after declining significantly between March and May 2020, new presentations of diabetes mellitus increased significantly during most of 2021 (peak adjusted RR 1.49, 95% CI 1.28-1.74 in July 2021) and much of 2022. Among these children, presentations for diabetic ketoacidosis were significantly higher than expected during the pandemic overall (adjusted RR 1.14, 95% CI 1.00-1.30). We observed similar time trends for new presentations of cancer, but we observed no excess presentations of severe cancer overall (adjusted RR 0.91, 95% CI 0.62-1.34). INTERPRETATION: In the first 30 months of the pandemic, disruptions to care were associated with important delays in new diagnoses of diabetes but not with other acute presentations of select preventable conditions or with mortality. Mitigation strategies in future pandemics or other health system disruptions should include education campaigns around important symptoms in children that require medical attention.

Severe Respiratory Disease Among Children With and Without Medical Complexity During the COVID-19 Pandemic.

Importance: Severe respiratory disease declined during the COVID-19 pandemic, partially due to decreased circulation of respiratory pathogens. However, the outcomes of children with higher risk have not been described using population-based data. Objective: To compare respiratory-related hospitalizations, intensive care unit (ICU) admissions, and mortality during the pandemic vs prepandemic, among children with medical complexity (CMC) and without medical complexity (non-CMC). Design, Setting, and Participants: This population-based repeated cross-sectional study used Canadian health administrative data of children aged younger than 18 years in community and pediatric hospitals during a pandemic period (April 1, 2020, to February 28, 2022) compared with a 3-year prepandemic period (April 1, 2017, to March 31, 2020). The pandemic period was analyzed separately for year 1 (April 1, 2020, to March 31, 2021) and year 2 (April 1, 2021, to February 28, 2022). Statistical analysis was performed from October 2022 to April 2023. Main Outcomes and Measures: Respiratory-related hospitalizations, ICU admissions, and mortality before and during the pandemic among CMC and non-CMC. Results: A total of 139 078 respiratory hospitalizations (29 461 respiratory hospitalizations for CMC and 109 617 for non-CMC) occurred during the study period. Among CMC, there were fewer respiratory hospitalizations in both 2020 (rate ratio [RR], 0.44 [95% CI, 0.42-0.46]) and 2021 (RR, 0.55 [95% CI, 0.51-0.62]) compared with the prepandemic period. Among non-CMC, there was an even larger relative reduction in respiratory hospitalizations in 2020 (RR, 0.18 [95% CI, 0.17-0.19]) and a similar reduction in 2021 (RR, 0.55 [95% CI, 0.54-0.56]), compared with the prepandemic period. Reductions in ICU admissions for respiratory illness followed a similar pattern for CMC (2020: RR, 0.56 [95% CI, 0.53-0.59]; 2021: RR, 0.66 [95% CI, 0.63-0.70]) and non-CMC (2020: RR, 0.22 [95% CI, 0.20-0.24]; RR, 0.65 [95% CI, 0.61-0.69]). In-hospital mortality for these conditions decreased among CMC in both 2020 (RR, 0.63 [95% CI, 0.51-0.77]) and 2021 (RR, 0.72 [95% CI, 0.59-0.87]). Conclusions and Relevance: This cross-sectional study found a substantial decrease in severe respiratory disease resulting in hospitalizations, ICU admissions, and mortality during the first 2 years of the pandemic compared with the 3 prepandemic years. These findings suggest that future evaluations of the effect of public health interventions aimed at reducing circulating respiratory pathogens during nonpandemic periods of increased respiratory illness may be warranted.

New and continuing physician-based outpatient mental health care among children and adolescents during the COVID-19 pandemic in Ontario, Canada: a population-based study.

Objective: To assess physician-based mental health care utilization during the COVID-19 pandemic among children and adolescents new to care and those already engaged with mental health services, and to evaluate differences by sociodemographic factors. Study design: We performed a population-based repeated cross-sectional study using linked health and administrative databases in Ontario, Canada among all children and adolescents 3-17 years. We examined outpatient visit rates per 1,000 population for mental health concerns for those new to care (no physician-based mental healthcare for ≥1 year) and those with continuing care needs (any physician-based mental healthcare <1 year) following onset of the pandemic. Results: Among ~2.5 million children and adolescents (48.7% female, mean age 10.1 ± 4.3 years), expected monthly mental health outpatient visits were 1.5/1,000 for those new to mental health care and 5.4/1,000 for those already engaged in care. Following onset of the pandemic, visit rates for both groups were above expected [adjusted rate ratio (aRR) 1.22, 95% CI 1.17, 1.27; aRR 1.10, 95% CI 1.07, 1.12] for new and continuing care, respectively. The greatest increase above expected was among females (new: aRR 1.33, 95% CI 1.25, 1.42; continuing: aRR 1.22 95% CI 1.17, 1.26) and adolescents ages 13-17 years (new: aRR 1.31, 95% CI 1.27, 1.34; continuing: aRR 1.15 95% CI 1.13, 1.17). Mood and anxiety concerns were prominent among those new to care. Conclusion: In the 18 months following onset of the pandemic, outpatient mental health care utilization increased for those with new and continuing care needs, especially among females and adolescents.

SARS-CoV-2 vaccination prevalence by mental health diagnosis: a population-based cross-sectional study in Ontario, Canada.

BACKGROUND: Since the onset of the COVID-19 pandemic, there has been concern about the impact of SARS-CoV-2 infection among individuals with mental illnesses. We analyzed the SARS-CoV-2 vaccination status of Ontarians with and without a history of mental illness. METHODS: We conducted a population-based cross-sectional study of all community-dwelling Ontario residents aged 19 years and older as of Sept. 17, 2021. We used health administrative data to categorize Ontario residents with a mental disorder (anxiety, mood, substance use, psychotic or other disorder) within the previous 5 years. Vaccine receipt as of Sept. 17, 2021, was compared between individuals with and without a history of mental illness. RESULTS: Our sample included 11 900 868 adult Ontario residents. The proportion of individuals not fully vaccinated (2 doses) was higher among those with substance use disorders (37.7%) or psychotic disorders (32.6%) than among those with no mental disorders (22.9%), whereas there were similar proportions among those with anxiety disorders (23.5%), mood disorders (21.5%) and other disorders (22.1%). After adjustment for age, sex, neighbourhood income and homelessness, individuals with psychotic disorders (adjusted prevalence ratio 1.19, 95% confidence interval [CI] 1.18-1.20) and substance use disorders (adjusted prevalence ratio 1.35, 95% CI 1.34-1.35) were more likely to be partially vaccinated or unvaccinated relative to individuals with no mental disorders. INTERPRETATION: Our study found that psychotic disorders and substance use disorders were associated with an increased prevalence of being less than fully vaccinated. Efforts to ensure such individuals have access to vaccinations, while challenging, are critical to ensuring the ongoing risks of death and other adverse consequences of SARS-CoV-2 infection are mitigated in this high-risk population.

Acute presentations of eating disorders among adolescents and adults before and during the COVID-19 pandemic in Ontario, Canada.

BACKGROUND: Increased rates of pediatric eating disorders have been observed during the COVID-19 pandemic, but little is known about trends among adults. We aimed to evaluate rates of emergency department visits and hospital admissions for eating disorders among adolescents and adults during the pandemic. METHODS: We conducted a population-based, repeated cross-sectional study using linked health administrative data for Ontario residents aged 10-105 years during the prepandemic (Jan. 1, 2017, to Feb. 29, 2020) and pandemic (Mar. 1, 2020, to Aug. 31, 2022) periods. We evaluated monthly rates of emergency department visits and hospital admissions for eating disorders, stratified by age. RESULTS: Compared with expected rates derived from the prepandemic period, emergency department visits for eating disorders increased during the pandemic among adolescents aged 10-17 years (7.38 v. 3.33 per 100 000; incidence rate ratio [IRR] 2.21, 95% confidence interval [CI] 2.17-2.26), young adults aged 18-26 years (2.79 v. 2.46 per 100 000; IRR 1.13, 95% CI 1.10-1.16) and older adults aged 41-105 years (0.14 v. 0.11 per 100 000; IRR 1.15, 95% CI 1.07-1.24). Hospital admissions for eating disorders increased during the pandemic for adolescents (8.82 v. 5.74 per 100 000; IRR 1.54, 95% CI 1.54-1.54) but decreased for all adult age groups, especially older adults aged 41-105 years (0.21 v. 0.30 per 100 000; IRR 0.72, 95% CI 0.64-0.80). INTERPRETATION: Emergency department visits for eating disorders increased among adolescents, young adults and older adults during the pandemic, but hospital admissions increased only for adolescents and decreased for all adult groups. Differential rates of acute care use for eating disorders by age have important implications for allocation of inpatient mental health resources.

Newborn and Early Infant Outcomes Following Maternal COVID-19 Vaccination During Pregnancy.

Importance: The study team previously showed that maternal mRNA COVID-19 vaccination during pregnancy confers protection against SARS-CoV-2 infection and COVID-19-related hospital admission in newborns and young infants. In this study, the study team evaluated newborn and early infant safety outcomes following maternal messenger RNA (mRNA) COVID-19 vaccination during pregnancy, for which there is limited comparative epidemiological evidence. Objective: To determine if maternal mRNA COVID-19 vaccination during pregnancy is associated with adverse newborn and early infant outcomes. Design, Setting, and Participants: This population-based retrospective cohort study took place in Ontario, Canada, using multiple linked health administrative databases. Singleton live births with an expected delivery date between May 1, 2021, and September 2, 2022, were included. Data were analyzed from January 2023 through March 2023. Exposure: Maternal mRNA COVID-19 vaccination (1 or more doses) during pregnancy. Main Outcomes and Measures: Severe neonatal morbidity (SNM), neonatal death, neonatal intensive care unit (NICU) admission, neonatal readmission, and hospital admission up to 6 months of age. The study team calculated inverse probability of treatment weighted risk ratios (RRs) and fit weighted Cox proportional hazards regression models comparing outcomes in infants of mothers who received COVID-19 vaccination during pregnancy with those who received no COVID-19 vaccine doses before delivery. Results: In total, 142 006 infants (72 595 male [51%]; mean [SD] gestational age at birth, 38.7 [1.7] weeks) were included; 85 670 were exposed to 1 or more COVID-19 vaccine doses in utero (60%). Infants of vaccinated mothers had lower risks of SNM (vaccine exposed 7.3% vs vaccine unexposed 8.3%; adjusted RR [aRR], 0.86; 95% CI, 0.83-0.90), neonatal death (0.09% vs 0.16%; aRR, 0.47; 95% CI, 0.33-0.65), and NICU admission (11.4% vs 13.1%; aRR, 0.86; 95% CI, 0.83-0.89). There was no association between maternal vaccination during pregnancy and neonatal readmission (5.5% vs 5.1%; adjusted hazard ratio, 1.03; 95% CI, 0.98-1.09) or 6-month hospital admission (8.4% vs 8.1%; adjusted hazard ratio, 1.01; 95% CI, 0.96-1.05). Conclusions and Relevance: In this population-based cohort study in Ontario, Canada, maternal mRNA COVID-19 vaccination during pregnancy was associated with lower risks of SNM, neonatal death, and NICU admission. In addition, neonatal and 6-month readmissions were not increased in infants of mothers vaccinated during pregnancy.

COVID-19 vaccine equity: a retrospective population-based cohort study examining primary series and first booster coverage among persons with a history of immigration and other residents of Ontario, Canada.

Introduction: Immigrants were disproportionately impacted by COVID-19 and experience unique vaccination barriers. In Canada (37 million people), 23% of the population is foreign-born. Immigrants constitute 60% of the country's racialized (non-white) population and over half of immigrants reside in Ontario, the country's most populous province. Ontario had several strategies aimed at improving vaccine equity including geographic targeting of vaccine supply and clinics, as well as numerous community-led efforts. Our objectives were to (1) compare primary series vaccine coverage after it was widely available, and first booster coverage 6 months after its availability, between immigrants and other Ontario residents and (2) identify subgroups experiencing low coverage. Materials and methods: Using linked immigration and health administrative data, we conducted a retrospective population-based cohort study including all community-dwelling adults in Ontario, Canada as of January 1, 2021. We compared primary series (two-dose) vaccine coverage by September 2021, and first booster (three-dose) coverage by March 2022 among immigrants and other Ontarians, and across sociodemographic and immigration characteristics. We used multivariable log-binomial regression to estimate adjusted risk ratios (aRR). Results: Of 11,844,221 adults, 22% were immigrants. By September 2021, 72.6% of immigrants received two doses (vs. 76.4%, other Ontarians) and by March 2022 46.1% received three doses (vs. 58.2%). Across characteristics, two-dose coverage was similar or slightly lower, while three-dose coverage was much lower, among immigrants compared to other Ontarians. Across neighborhood SARS-CoV-2 risk deciles, differences in two-dose coverage were smaller in higher risk deciles and larger in the lower risk deciles; with larger differences across all deciles for three-dose coverage. Compared to other Ontarians, immigrants from Central Africa had the lowest two-dose (aRR = 0.60 [95% CI 0.58-0.61]) and three-dose coverage (aRR = 0.36 [95% CI 0.34-0.37]) followed by Eastern Europeans and Caribbeans, while Southeast Asians were more likely to receive both doses. Compared to economic immigrants, resettled refugees and successful asylum-claimants had the lowest three-dose coverage (aRR = 0.68 [95% CI 0.68-0.68] and aRR = 0.78 [95% CI 0.77-0.78], respectively). Conclusion: Two dose coverage was more equitable than 3. Differences by immigrant region of birth were substantial. Community-engaged approaches should be re-invigorated to close gaps and promote the bivalent booster.

Association of maternal risk factors with infant maltreatment: an administrative data cohort study.

OBJECTIVE: We aimed to evaluate the risk of infant maltreatment associated with commonly used criteria for home visiting programmes: young maternal age, maternal adversity (homelessness, substance abuse, intimate partner violence), newcomer status and mental health concerns in Ontario, Canada. DESIGN: This retrospective cohort study included infants born in hospital in Ontario from 1 April 2005 to 31 March 2017 captured in linked health administrative and demographic databases. Infants were followed from newborn hospitalisation until 1 year of age for child maltreatment captured in healthcare or death records. The association between type and number of maternal risk factors, and maltreatment, was analysed using multivariable logistic regression modelling, controlling for infant characteristics and material deprivation. Further modelling explored the association of each year of maternal age with maltreatment. RESULTS: Of 989 586 infants, 434 (0.04%) had recorded maltreatment. Maternal age <22 years conferred higher risk of infant maltreatment (adjusted OR (aOR) 5.5, 95% CI 4.5 to 6.8) compared with age ≥22 years. Maternal mental health diagnoses (aOR 2.0, 95% CI 1.6 to 2.5) were also associated with maltreatment, while refugee status appeared protective (aOR 0.6, 95% CI 0.4 to 1.0). The odds of maltreatment increased with higher numbers of maternal risk factors. Maternal age was associated with maltreatment until age 28 years. CONCLUSION: Infants born to young mothers are at greater risk of infant maltreatment, and this association remained until age 28 years. These findings are important for ensuring public health interventions are supporting populations experiencing structural vulnerabilities with the aim of preventing maltreatment.

Self-harm among youth during the first 28 months of the COVID-19 pandemic in Ontario, Canada: a population-based study.

BACKGROUND: Youth have reported worsening mental health during the COVID-19 pandemic. We sought to evaluate rates of pediatric acute care visits for self-harm during the pandemic according to age, sex and mental health service use. METHODS: We conducted a population-based, repeated cross-sectional study using linked health administrative data sets to measure monthly rates of emergency department visits and hospital admissions for self-harm among youth aged 10-17 years between Jan. 1, 2017, and June 30, 2022, in Ontario, Canada. We modelled expected rates of acute care visits for self-harm after the pandemic onset based on prepandemic rates. We reported relative differences between observed and expected monthly rates overall and by age group (10-13 yr and 14-17 yr), sex and mental health service use (new and continuing). RESULTS: In this population of about 1.3 million children and adolescents, rates of acute care visits for self-harm during the pandemic were higher than expected for emergency department visits (0.27/1000 population v. 0.21/1000 population; adjusted rate ratio [RR] 1.29, 95% confidence interval [CI] 1.19-1.39) and hospital admissions (0.74/10 000 population v. 0.43/10 000 population, adjusted RR 1.72, 95% CI 1.46-2.03). This increase was primarily observed among females. Rates of emergency department visits and hospital admissions for self-harm were higher than expected for both those aged 10-13 years and those aged 14-17 years, as well as for both those new to the mental health system and those already engaged in care. INTERPRETATION: Rates of acute care visits for self-harm among children and adolescents were higher than expected during the first 2 and a half years of the COVID-19 pandemic, particularly among females. These findings support the need for accessible and intensive prevention efforts and mental health supports in this population.

Comparison of Emergency Department Use Between Pregnant People With and Without Disabilities in Ontario, Canada.

Importance: Emergency department (ED) use in pregnancy is common and occurs for a variety of reasons, including obstetrical complications, exacerbated underlying conditions, and inadequate outpatient health care access. People with disabilities have elevated rates of certain medical, psychiatric, and obstetrical conditions as well as inadequate access to prenatal care; their risk of ED use in pregnancy is not known, however. Objective: To compare the risk of ED use in pregnancy among people with physical, sensory, and intellectual or developmental disabilities with those without disabilities. Design, Setting, and Participants: Population-based cohort study leveraging linked administrative health data sets in Ontario, Canada, April 2003 to March 2019. Analysis included all recognized pregnancies to people with a preexisting physical, sensory, intellectual or developmental, or 2 or more (multiple) disabilities, and those without a disability. Data were analyzed from May 2022 to January 2023. Exposure: Disability was ascertained using algorithms applied to 2 or more outpatient physician visits or 1 or more ED visits or hospitalizations before conception. Main outcomes and measures: Modified Poisson regression-generated adjusted relative risks (aRR) and 95% CIs for any ED visit in pregnancy, from the estimated conception date up to the end of the pregnancy, adjusted for age, parity, income quintile, rurality, immigrant status, and preexisting chronic conditions, mental illness, and substance use disorders. Results: The cohort included 2 659 895 pregnant people with physical (221 739 participants; mean [SD] age, 29.8 [6.1] years), sensory (71 891 participants; mean [SD] age, 29.1 [6.4] years), intellectual or developmental (3877 participants; mean [SD] age, 26.1 [6.7] years), and multiple disabilities (14 359 participants; mean [SD] age, 29.5 [6.5] years), and pregnant people without a disability (2 348 023 participants; mean [SD] age, 29.4 [5.9] years). The rate of ED visits in pregnancy was 25.4% in people without a disability (596 771 visits). Relative to these individuals, the aRR for ED use was elevated in people with physical (aRR, 1.26; 95% CI, 1.25-1.27), sensory (aRR, 1.15; 95% CI, 1.14-1.17), intellectual or developmental (aRR, 1.33; 95% CI, 1.28-1.38), and multiple disabilities (aRR, 1.43; 95% CI, 1.40-1.46). Conclusions and Relevance: In this population-based study, people with disabilities were at elevated risk of ED use in pregnancy. This finding underscores the need for research on the benefits of proactive strategies to manage preexisting conditions in these individuals, improve their access to outpatient obstetrical and medical care, and prepare them for when ED visits occur.

Population-Based Repeated Cross-Sectional Study of Hospitalizations for Comorbid Physical and Psychiatric Disorders in Young Adults in Ontario, Canada.

PURPOSE: To measure trends in the rates and costs of hospitalizations over a 15-year period among young adults with physical and/or psychiatric disorders. METHODS: This population-based, repeated cross-sectional study identified all 18- to 26- year-olds hospitalized in Ontario, Canada from April 1, 2003 and March 31, 2018 (fiscal years 2003-2017). Using discharge diagnoses, we assigned hospitalizations to one of four categories: 1) psychiatric disorder only; 2) primary psychiatric disorder with comorbid physical illness; 3) primary physical with comorbid psychiatric disorder; and 4) physical illness only. We compared health service utilization and changes in rates of hospitalizations over time using restricted cubic spline regression. Secondary outcome measures included change in hospital costs for each hospitalization category over the study period. RESULTS: Of 1,076,951 hospitalizations in young adults (73.7% female), 195,726 (18.2%) had a psychiatric disorder (either primary or comorbid). There were 129,676 hospitalizations (12.0%) with psychiatric disorders only, 36,287 (3.4%) with primary psychiatric and comorbid physical disorders, 29,763 (2.8%) with primary physical and comorbid psychiatric disorders, and 881,225 (81.8%) with physical disorders only. Rates of hospitalization for psychiatric disorders only increased 81% from 4.32 to 7.84/1,000 population, and those with physical health disorders with comorbid psychiatric disorders increased 172% from 0.47 to 1.28/1,000 population. Substance-related disorders were the most common comorbid psychiatric disorders among youth hospitalized for physical illness and increased 260% from 0.9 to 3.3/1,000 population. DISCUSSION: Hospitalizations among young adults with primary and comorbid psychiatric disorders have increased significantly over the past 15 years. Health system resources should be adequately directed to meet the shifting and complex needs of hospitalized young adults.

Association between physician characteristics and practice-level uptake of paediatric virtual mental healthcare: a population-based study.

OBJECTIVE: To examine physician factors associated with practice-level uptake of virtual mental healthcare for children and adolescents. DESIGN, SETTING AND PARTICIPANTS: A population-based data linkage study of a cohort of all physicians (n=12 054) providing outpatient mental healthcare to children and adolescents (aged 3-17 years, n=303 185) in a single-payer provincial health system in Ontario, Canada from 1 July 2020 to 31 July 2021. EXPOSURES: Physician characteristics including gender, age, specialty, location of training, practice region, practice size and overall and mental health practice size. MAIN OUTCOMES: Practice-level proportion of outpatient virtual care provided: (1) mostly in-person (<25% virtual care), (2) hybrid (25%-99% virtual care) or (3) exclusively virtual (100% virtual care). Multinomial logistic regression models tested the association between practice-level virtual care provided and physician characteristics. RESULTS: Among physicians, 1589 (13.2%) provided mostly in-person mental healthcare with 8714 (67.8%) providing hybrid care, and 2291 (19.0%) providing exclusively virtual care. The provision of exclusive virtual care (vs mostly in-person) was associated with female sex (adjusted OR (aOR) 1.97, 95% CI 1.70 to 2.27 (ref: male)), foreign training (aOR 1.27, 95% CI 1.07 to 1.50 (ref: Canadian-trained)), family physicians (aOR 2.05, 95% CI 1.56 to 2.69 (ref: psychiatrist)) and reversely associated with large practice size (aOR 0.32, 95% CI 0.25 to 0.40 (ref smallest quintile)). Mostly in-person care was associated with older age physicians (71+ years) and practice outside the Toronto region. CONCLUSIONS AND RELEVANCE: In a single-payer universal healthcare system that remunerates physicians using the same fee structure for in-person and virtual outpatient care, there is heterogeneity in utilisation of virtual care that is associated with provider factors. This practice variation, with limited evidence on effectiveness and appropriate contexts for virtual care use, suggests there may be opportunity for further outcomes research and guidance on appropriate context for paediatric virtual mental healthcare delivery.

Gaps in childhood immunizations and preventive care visits during the COVID-19 pandemic: a population-based cohort study of children in Ontario and Manitoba, Canada, 2016-2021.

OBJECTIVE: We aimed to estimate the changes to the delivery of routine immunizations and well-child visits through the pandemic. METHODS: Using linked administrative health data in Ontario and Manitoba, Canada (1 September 2016 to 30 September 2021), infants <12 months old (N=291,917 Ontario, N=33,994 Manitoba) and children between 12 and 24 months old (N=293,523 Ontario, N=33,001 Manitoba) exposed and unexposed to the COVID-19 pandemic were compared on rates of receipt of recommended a) vaccinations and b) well-child visits after adjusting for sociodemographic measures. In Ontario, vaccinations were captured using physician billings database, and in Manitoba they were captured in a centralized vaccination registry. RESULTS: Exposed Ontario infants were slightly more likely to receive all vaccinations according to billing data (62.5% exposed vs. 61.6% unexposed; adjusted Relative Rate (aRR) 1.01 [95% confidence interval (CI) 1.00-1.02]) whereas exposed Manitoba infants were less likely to receive all vaccines (73.5% exposed vs. 79.2% unexposed; aRR 0.93 [95% CI 0.92-0.94]). Among children exposed to the pandemic, total vaccination receipt was modestly decreased compared to unexposed (Ontario aRR 0.98 [95% CI 0.97-0.99]; Manitoba aRR 0.93 [95% CI 0.91-0.94]). Pandemic-exposed infants were less likely to complete all recommended well-child visits in Ontario (33.0% exposed, 48.8% unexposed; aRR 0.67 [95% CI 0.68-0.69]) and Manitoba (55.0% exposed, 70.7% unexposed; aRR 0.78 [95% CI 0.77-0.79]). A similar relationship was observed for rates of completed well-child visits among children in Ontario (aRR 0.78 [95% CI 0.77-0.79]) and Manitoba (aRR 0.79 [95% CI 0.77-0.80]). CONCLUSION: Through the first 18 months of the pandemic, routine vaccines were delivered to children < 2 years old at close to pre-pandemic rates. There was a high proportion of incomplete well-child visits, indicating that developmental surveillance catch-up is crucial.

RéSUMé: OBJECTIF: Nous avons voulu estimer les changements dans l'administration des vaccins de routine et dans les consultations pédiatriques pendant la pandémie. MéTHODE: À l'aide des données administratives sur la santé couplées de l'Ontario et du Manitoba, au Canada (1er septembre 2016 au 30 septembre 2021), nous avons comparé les taux de réception : a) des vaccins recommandés et b) des consultations pédiatriques recommandées pour les nourrissons de < 12 mois (N = 291 917 en Ontario, N = 33 994 au Manitoba) et pour les enfants de 12 à 24 mois (N = 293 523 en Ontario, N = 33 001 au Manitoba) exposés et non exposés à la pandémie de COVID-19, après ajustement en fonction de mesures sociodémographiques. En Ontario, les vaccins ont été saisis à l'aide de la base de données des factures des médecins; au Manitoba, ils ont été saisis dans un registre de vaccination centralisé. RéSULTATS: Les nourrissons exposés en Ontario étaient légèrement plus susceptibles de recevoir tous les vaccins selon les données de facturation (62,5 % pour les nourrissons exposés c. 61,6 % pour les nourrissons non exposés; risque relatif ajusté [RRa] 1,01 [intervalle de confiance (IC) de 95 % 1,00-1,02]), tandis que les nourrissons exposés au Manitoba étaient moins susceptibles de recevoir tous les vaccins (73,5 % pour les nourrissons exposés c. 79,2 % pour les nourrissons non exposés; RRa 0,93 [IC de 95 % 0,92-0,94]). Chez les enfants exposés à la pandémie, le total des vaccins reçus était un peu plus faible que chez les enfants non exposés (RRa en Ontario 0,98 [IC de 95 % 0,97-0,99]; RRa au Manitoba 0,93 [IC de 95 % 0,91-0,94]). Les nourrissons exposés à la pandémie étaient moins susceptibles d'avoir eu toutes les consultations pédiatriques recommandées en Ontario (33 % pour les nourrissons exposés, 48,8 % pour les nourrissons non exposés; RRa 0,67 [IC de 95 % 0,68-0,69]) comme au Manitoba (55 % pour les nourrissons exposés, 70,7 % pour les nourrissons non exposés; RRa 0,78 [IC de 95 % 0,77-0,79]). Une relation semblable a été observée pour les taux de consultations pédiatriques complètes chez les enfants en Ontario (RRa 0,78 [IC de 95 % 0,77-0,79]) et au Manitoba (RRa 0,79 [(IC de 95 % 0,77-0,80]). CONCLUSION: Au cours des 18 premiers mois de la pandémie, les vaccins de routine ont été administrés aux enfants de < 2 ans à des taux proches de ceux d'avant la pandémie. Il y a eu une forte proportion de consultations pédiatriques incomplètes, ce qui indique qu'il est essentiel de rattraper la surveillance du développement.

COVID-19 Vaccine Uptake in Immigrant, Refugee, and Nonimmigrant Children and Adolescents in Ontario, Canada.

Importance: COVID-19 vaccinations are recommended for minors. Surveys indicate lower vaccine acceptance by some immigrant and refugee groups. Objective: To identify characteristics in immigrant, refugee, and nonimmigrant minors associated with vaccination. Design, Setting, and Participants: This retrospective cohort study used linked, population-based demographic and health care data from Ontario, Canada, including all children aged 4 to 17 years registered for universal health insurance on January 1, 2021, across 2 distinct campaigns: for adolescents (ages 12-17 years), starting May 23, 2021, and for children (ages 5-11 years), starting November 25, 2021, through April 24, 2022. Data were analyzed from May 9 to August 2, 2022. Exposures: Immigrant or refugee status and immigration characteristics (recency, category, region of origin, and generation). Main Outcomes and Measures: Outcomes of interest were crude rates of COVID-19 vaccination (defined as ≥1 vaccination for children and ≥2 vaccinations for adolescents) and adjusted odds ratios (aORs) with 95% CIs for vaccination, adjusted for clinical, sociodemographic, and health system factors. Results: The total cohort included 2.2 million children and adolescents, with 1 098 749 children (mean [SD] age, 7.06 [2.00] years; 563 388 [51.3%] males) and 1 142 429 adolescents (mean [SD] age, 14.00 [1.99] years; 586 617 [51.3%] males). Among children, 53 090 (4.8%) were first-generation and 256 886 (23.4%) were second-generation immigrants or refugees; among adolescents, 104 975 (9.2%) were first-generation and 221 981 (19.4%) were second-generation immigrants or refugees, most being economic or family-class immigrants. Immigrants, particularly refugees, were more likely to live in neighborhoods with highest material deprivation (first-generation immigrants: 18.6% of children and 20.2% of adolescents; first-generation refugees: 46.4% of children and 46.3% of adolescents; nonimmigrants: 18.5% of children and 17.2% of adolescents) and COVID-19 risk (first-generation immigrants; 20.0% of children and 20.5% of adolescents; first-generation refugees: 9.4% of children and 12.6% of adolescents; nonimmigrants: 6.9% of children and 6.8% of adolescents). Vaccination rates (53.1% in children and 79.2% in adolescents) were negatively associated with material deprivation. In both age groups, odds for vaccination were higher in immigrants (children: aOR, 1.30; 95% CI, 1.27-1.33; adolescents: aOR, 1.10; 95% CI, 1.08-1.12) but lower in refugees (children: aOR, 0.34; 95% CI, 0.33-0.36; adolescents: aOR, 0.88; 95% CI, 0.84-0.91) compared with nonimmigrants. In immigrant- and refugee-only models stratified by generation, region of origin was associated with uptake, compared with the overall rate, with the lowest odds observed in immigrants and refugees from Eastern Europe (children: aOR, 0.40; 95% CI, 0.35-0.46; adolescents: aOR, 0.41; 95% CI, 0.38-0.43) and Central Africa (children: aOR, 0.24; 95% CI, 0.16-0.35; adolescents: aOR, 0.51,CI: 0.45-0.59) and the highest odds observed in immigrants and refugees from Southeast Asia (children: aOR, 2.68; 95% CI, 2.47-2.92; adolescents aOR, 4.42; 95% CI, 4.10-4.77). Adjusted odds of vaccination among immigrants and refugees from regions with lowest vaccine coverage were similar across generations. Conclusions and Relevance: In this cohort study using a population-based sample in Canada, nonrefugee immigrants had higher vaccine coverage than nonimmigrants. Substantial heterogeneity by region of origin and lower vaccination coverage in refugees persisted across generations. These findings suggest that vaccine campaigns need precision public health approaches targeting specific barriers in identified, undervaccinated subgroups.

Primary health care utilization in the first year after arrival by refugee sponsorship model in Ontario, Canada: A population-based cohort study.

BACKGROUND: Canada's approach to refugee resettlement includes government sponsorship, a pioneering private sponsorship model and a third blended approach. Refugees are selected and supported differently in each approach including healthcare navigation. Little is known about how well private sponsors facilitate primary care navigation and whether this changed during the large-scale 2015 Syrian resettlement initiative characterized by civic and healthcare systems engagement. METHODS AND FINDINGS: Population-based cohort study of resettled refugees arriving in Ontario between April 1, 2008 and March 31, 2017, with one-year follow-up, using linked health and demographic administrative databases. We evaluated associations of resettlement model (GARs, Privately Sponsored Refugees [PSRs], and Blended-Visa Office Referred [BVORs]) by era of arrival (pre-Syrian and Syrian era) and by country cohort, on measures of primary care (PC) navigation using adjusted Cox proportional hazards and logistic regression. There were 34,591 (pre-Syrian) and 24,757 (Syrian era) resettled refugees, approximately half of whom were GARs. Compared with the reference group pre-Syrian era PSRs, Syrian PSRs had slightly earlier PC visits (mean = 116 days [SD = 90]) (adjusted hazard ratios [aHR] = 1.19, 95% CI 1.14-1.23). Syrian GARs (mean = 72 days [SD = 65]) and BVORs (mean = 73 days [SD = 76]) had their first PC visit sooner than pre-Syrian era PSRs (mean = 149 days [SD = 86]), with respective aHRs 2.27, 95% CI 2.19-2.35 and 1.89, 95% CI 1.79-1.99. Compared to pre-Syrian PSRs, Syrian GARs and BVORs had much greater odds of a CHC visit (adjusted odds ratios 14.69, 95% CI 12.98-16.63 and 14.08, 95% 12.05-16.44 respectively) and Syrian PSRs had twice the odds of a CHC visit. CONCLUSIONS: Less timely primary care and lower odds of a CHC visit among PSRs in the first year may be attributed to selection factors and gaps in sponsors' knowledge of healthcare navigation. Improved primary care navigation outcomes in the Syrian era suggests successful health systems engagement.

Estimating the Incidence of First RSV Hospitalization in Children Born in Ontario, Canada.

BACKGROUND: Respiratory syncytial virus (RSV) contributes significantly to morbidity in children, placing substantial burdens on health systems, thus RSV vaccine development and program implementation are a public health priority. More data on burden are needed by policymakers to identify priority populations and formulate prevention strategies as vaccines are developed and licensed. METHODS: Using health administrative data, we calculated incidence rates of RSV hospitalization in a population-based birth cohort of all children born over a six-year period (May 2009 to June 2015) in Ontario, Canada. Children were followed until their first RSV hospitalization, death, 5th birthday, or the end of the study period (June 2016). RSV hospitalizations were identified using a validated algorithm based on International Classification of Diseases, 10th Revision, and/or laboratory-confirmed outcomes. We calculated hospitalization rates by various characteristics of interest, including calendar month, age groups, sex, comorbidities, and gestational age. RESULTS: The overall RSV hospitalization rate for children <5 years was 4.2 per 1000 person-years (PY) with a wide range across age groups (from 29.6 to 0.52 per 1000 PY in children aged 1 month and 36-59 months, respectively). Rates were higher in children born at a younger gestational age (23.2 per 1000 PY for those born at <28 weeks versus 3.9 per 1000 PY born at ≥37 weeks); this increased risk persisted as age increased. While the majority of children in our study had no comorbidities, rates were higher in children with comorbidities. For all age groups, rates were highest between December and March. CONCLUSIONS: Our results confirm the high burden of RSV hospitalization and highlight young infants are at additional risk, namely premature infants. These results can inform prevention efforts.

Prenatal opioid exposure and well-child care in the first 2 years of life: population-based cohort study.

OBJECTIVES: To quantify well-child visits by age 2 years and developmental screening at the 18-month enhanced well-child visit among children with prenatal opioid exposure (POE) and to identify factors associated with study outcomes. DESIGN: Population-based cohort study. SETTING: Ontario, Canada. PARTICIPANTS: 22 276 children with POE born 2014-2018 were classified as (1) 1-29 days of prescribed opioid analgesia, (2) 30+ days of prescribed opioid analgesia, (3) medication for opioid use disorder (MOUD), (4) MOUD and opioid analgesia, or (5) unregulated opioids. MAIN OUTCOME MEASURES: Attending ≥5 well-child visits by age 2 years and the 18-month enhanced well-child visit. Modified Poisson regression was used to examine factors associated with outcomes. RESULTS: Children with POE to 1-29 days of analgesics were most likely to attend ≥5 well-child visits (61.2%). Compared with these children, adjusted relative risks (aRRs) for ≥5 well-child visits were lower among those exposed to 30+ days of opioid analgesics (0.95, 95% CI 0.91 to 0.99), MOUD (0.83, 95% CI 0.79 to 0.88), MOUD and opioid analgesics (0.78 95% CI 0.68 to 0.90) and unregulated opioids (0.89, 95% CI 0.83 to 0.95). Relative to children with POE to 1-29 days of analgesics (58.5%), respective aRRs for the 18-month enhanced well-child visit were 0.92 (95% CI 0.88 to 0.96), 0.76 (95% CI 0.72 to 0.81), 0.76 (95% CI 0.66 to 0.87) and 0.82 (95% CI 0.76 to 0.88). Having a regular primary care provider was positively associated with study outcomes; socioeconomic disadvantage, rurality and maternal mental health were negatively associated. CONCLUSION: Well-child visits are low in children following POE, especially among offspring of mothers receiving MOUD or unregulated opioids. Strategies to improve attendance will be important for child outcomes.

Receipt of adequate prenatal care for privately sponsored versus government-assisted refugees in Ontario, Canada: a population-based cohort study.

BACKGROUND: Canada has 2 main streams of resettlement: government-assisted refugees and privately sponsored refugees, whereby citizens can privately sponsor refugees and provide resettlement services, including health care navigation. Our objective was to compare receipt of adequate prenatal care among privately sponsored and government-assisted refugees. METHODS: This population-based study used linked health administrative and demographic databases. We included all resettled refugees classified as female who landed in Ontario, Canada, between April 2002 and May 2017, and who had a live birth or stillbirth conceived at least 365 days after their landing date. Our primary outcome - adequacy of prenatal care - was a composite that comprised receipt of a first-trimester prenatal visit, the number of prenatal care visits recommended by the Society of Obstetricians and Gynaecologists of Canada and a prenatal fetal anatomy ultrasound. We accounted for potential confounding with inverse probability of treatment weighting, using a propensity score. RESULTS: We included 2775 government-assisted and 2374 privately sponsored refugees. Compared with privately sponsored refugees (62.3% v. 69.3%), government-assisted refugees received adequate prenatal care less often, with a weighted relative risk of 0.93 (95% confidence interval 0.88-0.95). INTERPRETATION: Among refugees resettled to Canada, a government-assisted resettlement model was associated with receiving less adequate prenatal care than a private sponsorship model. Government-assisted refugees may benefit from additional support in navigating health care beyond the first year after arrival.