Prescription Medication Use in Pregnancy in People with Disabilities: A Population-Based Cohort Study.

Background: Individuals with disabilities may require specific medications in pregnancy. The prevalence and patterns of medication use, overall and for medications with known teratogenic risks, are largely unknown. Methods: This population-based cohort study in Ontario, Canada, 2004-2021, comprised all recognized pregnancies among individuals eligible for public drug plan coverage. Included were those with a physical (n = 44,136), sensory (n = 13,633), intellectual or developmental (n = 2,446) disability, or multiple disabilities (n = 5,064), compared with those without a disability (n = 299,944). Prescription medication use in pregnancy, overall and by type, was described. Modified Poisson regression generated relative risks (aRR) for the use of medications with known teratogenic risks and use of ≥2 and ≥5 medications concurrently in pregnancy, comparing those with versus without a disability, adjusting for sociodemographic and clinical factors. Results: Medication use in pregnancy was more common in people with intellectual or developmental (82.1%), multiple (80.4%), physical (73.9%), and sensory (71.9%) disabilities, than in those with no known disability (67.4%). Compared with those without a disability (5.7%), teratogenic medication use in pregnancy was especially higher in people with multiple disabilities (14.2%; aRR 2.03, 95% confidence interval [CI]: 1.88-2.20). Furthermore, compared with people without a disability (3.2%), the use of ≥5 medications concurrently was more common in those with multiple disabilities (13.4%; aRR 2.21, 95% CI: 2.02-2.41) and an intellectual or developmental disability (9.3%; aRR 2.13, 95% CI: 1.86-2.45). Interpretation: Among people with disabilities, medication use in pregnancy is prevalent, especially for potentially teratogenic medications and polypharmacy, highlighting the need for preconception counseling/monitoring to reduce medication-related harm in pregnancy.

Healthcare Utilization and Costs in Children Receiving Home Mechanical Ventilation in Ontario: A 14-Year Cohort Study.

RATIONALE: Home mechanical ventilation (HMV) is an advanced medical therapy offered to children with medical complexity. Despite the growing pediatric HMV population in North America, there are limited studies describing healthcare utilization and predictors of highest costs using robust health administrative data. OBJECTIVES: To describe patterns of healthcare utilization and costs in children receiving HMV over a 14-year period in Ontario, Canada. METHODS: We conducted a retrospective population-based cohort study (April 1, 2003 to March 31, 2017) of children aged 0-18 years receiving HMV via invasive mechanical ventilation (IMV) or non-invasive ventilation (NIV). Paired t-tests compared healthcare system utilization and costs two years before and two years after HMV approval. We developed linear models to analyze variables associated with children in the top quartile of health service utilization and costs. RESULTS: We identified 835 children receiving HMV. In the two years after HMV approval compared to the 2 years prior, children had decreased hospitalization days (median 9 (IQR 3-30) versus 29 (6-99), p<0.0001) and ICU admission days (6.6 (1.9-18.0) versus 17.1 (3.3-70.9), p<0.0001) but had increased homecare service approvals (195 (24-522) versus 40 (12-225), p<0.0001) and outpatient Pulmonology visits (3 (1-4) versus 2 (1-3), p<0.0001). Total healthcare costs were higher in the two years after HMV approval (mean $164,892 (SD $214,187) versus $128,941 ($194,199), p<0.0001). However, all-cause hospital admission costs were reduced ($66,546 ($142,401) versus $81,578 ($164,672), p<0.0001). Highest total 2-year costs were associated with IMV (OR 3.45, 95% CI 2.24-5.31; reference NIV), number of medical devices at home (OR 1.63, 95% CI 1.35-1.96; reference no technology), and increased healthcare costs in the year prior to HMV initiation (OR 2.23, 95% CI 1.84-2.69). CONCLUSIONS: Children progressing to the need for HMV represent a worsening in their respiratory status that will undoubtedly increase healthcare utilization and costs. We found that the initiation of HMV in these children can reduce inpatient healthcare utilization and costs but can still increase overall healthcare expenditures, especially in the outpatient setting.

Pediatric Respiratory Syncytial Virus Hospitalizations, 2017-2023.

Importance: Respiratory syncytial virus (RSV) transmission was disrupted worldwide following the COVID-19 pandemic, and further study is required to better understand these changes. Objective: To compare observed and expected RSV hospital and intensive care unit (ICU) admission rates and characteristics of admitted children during the 2021-2022 and 2022-2023 seasons. Design, Setting, and Participants: A population-based cohort study of all children aged younger than 5 years in Ontario, Canada, July 1, 2017, through March 31, 2023, was conducted. Exposures: Individual and neighborhood-level sociodemographic and clinical characteristics were identified from administrative data, including age, palivizumab eligibility, complex medical conditions, rurality, and living in a marginalized neighborhood. Main Outcomes and Measures: The main outcome was RSV-associated hospitalization. Secondary outcomes included ICU admissions, mechanical ventilation, extracorporeal membrane oxygenation, and in-hospital death. Poisson generalized estimating equations were used to model weekly age- and sex-specific hospitalization rates and estimate expected rates in the postpandemic era; adjusted rate ratios (RRs) and 95% CIs are reported. Results: This cohort study included approximately 700 000 children per study year. Compared with prepandemic years (2017-2018, 2018-2019, and 2019-2020), the 2021-2022 RSV season peaked slightly earlier, but overall admission rates were comparable (289.1 vs 281.4-334.6 per 100 000, or approximately 2000 admissions). The 2022-2023 season peaked a month earlier and resulted in more than twice as many hospitalizations (770.0 per 100 000; n = 4977 admissions). The proportion of children admitted to an ICU in 2022-2023 (13.9%) was slightly higher than prepandemic (9.6%-11.4%); however, the population-based rate was triple the prepandemic levels (106.9 vs 27.6-36.6 per 100 000 children in Ontario). With the exception of palivizumab-eligible children, all sociodemographic and health status characteristics were associated with lower-than-expected RSV hospitalization rates in 2021-2022. In contrast, older age of patients was associated with higher-than-expected rates in 2022-2023 (ie, 24-59 months: RR, 1.90; 95% CI, 1.35-2.66). Conclusions and Relevance: There were notable differences in RSV epidemiologic characteristics in Ontario following the COVID-19 pandemic. It is not yet clear whether and how long atypical RSV epidemics may persist. Clinicians and program planners should consider the potential for ongoing impacts to health care capacity and RSV immunization programs.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.