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.

Postpartum Emergency Department Use Following Midwifery-Model vs Obstetrics-Model Care.

Importance: Emergency department (ED) use postpartum is a common and often-preventable event. Unlike traditional obstetrics models, the Ontario midwifery model offers early care postpartum. Objective: To assess whether postpartum ED use differs between women who received perinatal care in midwifery-model care vs in traditional obstetrics-model care. Design, Setting, and Participants: This retrospective population-based cohort study took place in Ontario, Canada, where public health care is universally funded. Participants included women who were low risk and primiparous and gave birth to a live baby in an Ontario hospital between 2012 and 2018. Data were collected from April 2012 to March 2018 and analyzed from June 2022 to April 2023. Exposures: Perinatal care clinician, namely, a midwife or obstetrician. Main Outcome and Measures: : Any unscheduled ED visit 42 days postpartum or less. Poisson regression models compared ED use between women with midwifery-model care vs obstetrics-model care, weighting by propensity score-based overlap weights. Results: Among 104 995 primiparous women aged 11 to 50 years, those in midwifery-model care received a median (IQR) of 7 (6-8) postpartum visits, compared with 0 (0-1) visits among those receiving obstetrics-model care. Unscheduled ED visits 42 days or less postpartum occurred for 1549 of 23 124 women (6.7%) with midwifery-model care compared with 6902 of 81 871 women (8.4%) with traditional obstetrics-model care (adjusted relative risks [aRR], 0.78; 95% CI, 0.73-0.83). Similar aRRs were seen in women with a spontaneous vaginal birth (aRR, 0.71; 95% CI, 0.65-0.78) or assisted vaginal birth (aRR, 0.70; 95% CI, 0.59-0.82) but not those with a cesarean birth (aRR, 0.94; 95% CI, 0.86-1.03) or those with intrapartum transfer of care between a midwife and obstetrician (aRR, 0.94; 95% CI, 0.87-1.04). ED use 7 days or less postpartum was also lower among women receiving midwifery model care (aRR, 0.70; 95% CI, 0.65-0.77). Conclusions and Relevance: In this cohort study, midwifery-model care was associated with less postpartum ED use than traditional obstetrics-model care among women who had low risk and were primiparous, which may be due to early access to postpartum care provided by Ontario midwives.

Hyponatremia-associated hospital visits are not reduced by early electrolyte testing in older adults starting antidepressants.

BACKGROUND: Clinical practice guidelines recommend early serum electrolyte monitoring when starting antidepressants in older adults due to the increased risk of hyponatremia. It is unclear whether this monitoring improves outcomes. METHODS: Population-based, retrospective cohort study of Ontario adults aged ≥66 years who initiated therapy with a selective serotonin reuptake inhibitor (SSRI) or selective norepinephrine reuptake inhibitor (SNRI) between April 1, 2013, and January 31, 2020. The index date was the date of the first such prescription, and the exposure of interest was serum electrolyte measurement during the subsequent 7 days. The primary outcome was any emergency department or hospital admission with hyponatremia within 8-60 days of antidepressant initiation. Poisson regression models compared individuals who had versus did not have their serum electrolytes tested in the week following SSRI/SNRI initiation, weighting by propensity score-based overlap weights. RESULTS: Among the 420,085 patients aged ≥66 years initiating treatment with an SSRI/SNRI, 26,808 (6.4%) had serum electrolytes measured in the subsequent 7 days and 6109 (1.5%) subsequently presented to hospital with hyponatremia. The time from drug initiation to hospitalization varied (median 29, interquartile range [IQR] 17-44 days), and the median sodium concentration measured in the community (136, IQR 133-138 mmol/L) was marginally higher than those at the time of hospitalization (132, IQR 130-134 mmol/L). Patients who underwent electrolyte testing in the week following SSRI/SNRI treatment were more likely to attend an emergency department (ED) or hospital with hyponatremia within 8-60 days relative to those who did not (relative risk = 2.31, 95% confidence interval: 2.16-2.46). CONCLUSIONS: Testing serum electrolytes in the week after starting an SSRI/SNRI is not associated with a reduced risk of a hospital visit with hyponatremia. These findings do not support current guidelines recommending routine electrolyte monitoring.

The relationship between relational continuity and family physician follow-up after an antidepressant prescription in older adults: a retrospective cohort study.

BACKGROUND: Side effects can occur within hours to days of starting antidepressant medications, whereas full therapeutic benefit for mood typically takes up to four weeks. This mismatch between time to harm and lag to benefit often leads to premature discontinuation of antidepressants, a phenomenon that can be partially reversed through early doctor-patient communication and follow-up. We investigated the relationship between relational continuity of care - the number of years family physicians have cared for older adult patients - and early follow-up care for patients prescribed antidepressants. METHODS: A retrospective cohort study was conducted on residents of Ontario, Canada aged 66 years or older who were dispensed their first antidepressant prescription through the provincial drug insurance program between April 1, 2016, and March 31, 2019. The study utilized multivariable regression to estimate the relationship between relational continuity and 30-day follow-up with the prescribing family physician. Separate estimates were generated for older adults living in urban, non-major urban, and rural communities. RESULTS: The study found a small positive relationship between relational continuity of care and follow-up care by the prescribing family physician for patients dispensed a first antidepressant prescription (RRR = 1.005; 95% CI = 1.004, 1.006). The relationship was moderated by the patients' location of dwelling, where the effect was stronger for older adults residing in non-major urban (RRR = 1.009; 95% CI = 1.007, 1.012) and rural communities (RRR = 1.006; 95% CI = 1.002, 1.011). CONCLUSIONS: Our findings do not provide strong evidence of a relationship between relational continuity of care and higher quality management of antidepressant prescriptions. However, the relationship is slightly more pronounced in rural communities where access to continuous primary care and specialized mental health services is more limited. This may support the ongoing need for the recruitment and retention of primary care providers in rural communities.

Association of virtual end-of-life care with healthcare outcomes before and during the COVID-19 pandemic: A population-based study.

The use of virtual care for people at the end-of-life significantly increased during the COVID-19 pandemic, but its association with acute healthcare use and location of death is unknown. The objective of this study was to measure the association between the use of virtual end-of-life care with acute healthcare use and an out-of-hospital death before vs. after the introduction of specialized fee codes that enabled broader delivery of virtual care during the COVID-19 pandemic. This was a population-based cohort study of 323,995 adults in their last 90 days of life between January 25, 2018 and December 31, 2021 using health administrative data in Ontario, Canada. Primary outcomes were acute healthcare use (emergency department, hospitalization) and location of death (in or out-of-hospital). Prior to March 14, 2020, 13,974 (8%) people received at least 1 virtual end-of-life care visit, which was associated with a 16% higher rate of emergency department use (adjusted Rate Ratio [aRR] 1.16, 95%CI 1.12 to 1.20), a 17% higher rate of hospitalization (aRR 1.17, 95%CI 1.15 to 1.20), and a 34% higher risk of an out-of-hospital death (aRR 1.34, 95%CI 1.31 to 1.37) compared to people who did not receive virtual end-of-life care. After March 14, 2020, 104,165 (71%) people received at least 1 virtual end-of-life care visit, which was associated with a 58% higher rate of an emergency department visit (aRR 1.58, 95%CI 1.54 to 1.62), a 45% higher rate of hospitalization (aRR 1.45, 95%CI 1.42 to 1.47), and a 65% higher risk of an out-of-hospital death (aRR 1.65, 95%CI 1.61 to 1.69) compared to people who did not receive virtual end-of-life care. The use of virtual end-of-life care was associated with higher acute healthcare use in the last 90 days of life and a higher likelihood of dying out-of-hospital, and these rates increased during the pandemic.

Attending physicians' annual service volume and use of virtual end-of-life care: A population-based cohort study in Ontario, Canada.

IMPORTANCE: Physicians and their practice behaviors influence access to healthcare and may represent potentially modifiable targets for practice-changing interventions. Use of virtual care at the end-of-life significantly increased during the COVID-19 pandemic, but its association with physician practice behaviors, (e.g., annual service volume) is unknown. OBJECTIVE: Measure the association of physicians' annual service volume with their use of virtual end-of-life care (EOLC) and the magnitude of physician-attributable variation in its use, before and during the pandemic. DESIGN, SETTING AND PARTICIPANTS: Population-based cohort study using administrative data of all physicians in Ontario, Canada who cared for adults in the last 90 days of life between 01/25/2018-12/31/2021. Multivariable modified Poisson regression models measured the association between attending physicians' use of virtual EOLC and their annual service volume. We calculated the variance partition coefficients for each regression and stratified by time period before and during the pandemic. EXPOSURE: Annual service volume of a person's attending physician in the preceding year. MAIN OUTCOMES AND MEASURES: Delivery of ≥1 virtual EOLC visit by a person's attending physician and the proportion of variation in its use attributable to physicians. RESULTS: Among the 35,825 unique attending physicians caring for 315,494 adults, use of virtual EOLC was associated with receiving care from a high compared to low service volume attending physician; the magnitude of this association diminished during the pandemic (adjusted RR 1.25 [95% CI 1.14, 1.37] pre-pandemic;1.10 (95% CI 1.08, 1.12) during the pandemic). Physicians accounted for 36% of the variation in virtual EOLC use pre-pandemic and 12% of this variation during the pandemic. CONCLUSIONS AND RELEVANCE: Physicians' annual service volume was associated with use of virtual EOLC and physicians accounted for a substantial proportion of the variation in its use. Physicians may be appropriate and potentially modifiable targets for interventions to modulate use of EOLC delivery.

Hospital-Level NICU Capacity, Utilization, and 30-Day Outcomes in Texas.

Importance: Risk-adjusted neonatal intensive care unit (NICU) utilization and outcomes vary markedly across regions and hospitals. The causes of this variation are poorly understood. Objective: To assess the association of hospital-level NICU bed capacity with utilization and outcomes in newborn cohorts with differing levels of health risk. Design, Setting, and Participants: This population-based retrospective cohort study included all Medicaid-insured live births in Texas from 2010 to 2014 using linked vital records and maternal and newborn claims data. Participants were Medicaid-insured singleton live births (LBs) with birth weights of at least 400 g and gestational ages between 22 and 44 weeks. Newborns were grouped into 3 cohorts: very low birth weight (VLBW; <1500 g), late preterm (LPT; 34-36 weeks' gestation), and nonpreterm newborns (NPT; ≥37 weeks' gestation). Data analysis was conducted from January 2022 to October 2023. Exposure: Hospital NICU capacity measured as reported NICU beds/100 LBs, adjusted (ie, allocated) for transfers. Main Outcomes and Measures: NICU admissions and special care days; inpatient mortality and 30-day postdischarge adverse events (ie, mortality, emergency department visit, admission, observation stay). Results: The overall cohort of 874 280 single LBs included 9938 VLBW (5054 [50.9%] female; mean [SD] birth weight, 1028.9 [289.6] g; mean [SD] gestational age, 27.6 [2.6] wk), 63 160 LPT (33 684 [53.3%] female; mean [SD] birth weight, 2664.0 [409.4] g; mean [SD] gestational age, 35.4 [0.8] wk), and 801 182 NPT (407 977 [50.9%] female; mean [SD] birth weight, 3318.7 [383.4] g; mean [SD] gestational age, 38.9 [1.0] wk) LBs. Median (IQR) NICU capacity was 0.84 (0.57-1.30) allocated beds/100 LB/year. For VLBW newborns, NICU capacity was not associated with the risk of NICU admission or number of special care days. For LPT newborns, birth in hospitals with the highest compared with the lowest category of capacity was associated with a 17% higher risk of NICU admission (adjusted risk ratio [aRR], 1.17; 95% CI, 1.01-1.33). For NPT newborns, risk of NICU admission was 55% higher (aRR, 1.55; 95% CI, 1.22-1.97) in the highest- vs the lowest-capacity hospitals. The number of special care days for LPT and NPT newborns was 21% (aRR, 1.21; 95% CI,1.08-1.36) and 37% (aRR, 1.37; 95% CI, 1.08-1.74) higher in the highest vs lowest capacity hospitals, respectively. Among LPT and NPT newborns, NICU capacity was associated with higher inpatient mortality and 30-day postdischarge adverse events. Conclusions and Relevance: In this cohort study of Medicaid-insured newborns in Texas, greater hospital NICU bed supply was associated with increased NICU utilization in newborns born LPT and NPT. Higher capacity was not associated with lower risk of adverse events. These findings raise important questions about how the NICU is used for newborns with lower risk.

Sex-Based Disparities in Acute Myocardial Infarction Treatment Patterns and Outcomes in Older Adults Hospitalized Across 6 High-Income Countries: An Analysis From the International Health Systems Research Collaborative.

BACKGROUND: Sex differences in acute myocardial infarction treatment and outcomes are well documented, but it is unclear whether differences are consistent across countries. The objective of this study was to investigate the epidemiology, use of interventional procedures, and outcomes for older females and males hospitalized with ST-segment-elevation myocardial infarction (STEMI) and non-ST-segment-elevation myocardial infarction (NSTEMI) in 6 diverse countries. METHODS: We conducted a serial cross-sectional cohort study of 1 508 205 adults aged ≥66 years hospitalized with STEMI and NSTEMI between 2011 and 2018 in the United States, Canada, England, the Netherlands, Taiwan, and Israel using administrative data. We compared females and males within each country with respect to age-standardized hospitalization rates, rates of cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass graft surgery within 90 days of hospitalization, and 30-day age- and comorbidity-adjusted mortality. RESULTS: Hospitalization rates for STEMI and NSTEMI decreased between 2011 and 2018 in all countries, although the hospitalization rate ratio (rate in males/rate in females) increased in virtually all countries (eg, US STEMI ratio, 1.58:1 in 2011 and 1.73:1 in 2018; Israel NSTEMI ratio, 1.71:1 in 2011 and 2.11:1 in 2018). Rates of cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass graft surgery were lower for females than males for STEMI in all countries and years (eg, US cardiac catheterization in 2018, 88.6% for females versus 91.5% for males; Israel percutaneous coronary intervention in 2018, 76.7% for females versus 84.8% for males) with similar findings for NSTEMI. Adjusted mortality for STEMI in 2018 was higher for females than males in 5 countries (the United States, Canada, the Netherlands, Israel, and Taiwan) but lower for females than males in 5 countries for NSTEMI. CONCLUSIONS: We observed a larger decline in acute myocardial infarction hospitalizations for females than males between 2011 and 2018. Females were less likely to receive cardiac interventions and had higher mortality after STEMI. Sex disparities seem to transcend borders, raising questions about the underlying causes and remedies.

Variation in the Care of Children with Inflammatory Bowel Disease Within and Across Canadian Provinces: A Multi-Province Population-Based Cohort Study.

Purpose: The incidence of childhood-onset inflammatory bowel disease (IBD) is rising. We described variation in health services utilization and need for surgery among children with IBD between six and 60 months following IBD diagnosis across Canadian pediatric centers and evaluated the associations between care provided at diagnosis at each center and the variation in these outcomes. Patients and Methods: Using population-based deterministically-linked health administrative data from four Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario) we identified children diagnosed with IBD <16 years of age using validated algorithms. Children were assigned to a pediatric center of care using a hierarchical approach based on where they received their initial care. Outcomes included IBD-related hospitalizations, emergency department (ED) visits, and IBD-related abdominal surgery occurring between 6 and sixty months after diagnosis. Mixed-effects meta-analysis was used to pool results and examine the association between center-level care provision and outcomes. Results: We identified 3784 incident cases of pediatric IBD, of whom 2937 (77.6%) were treated at pediatric centers. Almost a third (31.4%) of children had ≥1 IBD-related hospitalization and there were 0.66 hospitalizations per person during follow-up. More than half (55.8%) of children had ≥1 ED visit and there were 1.64 ED visits per person. Between-center heterogeneity was high for both outcomes; centers where more children visited the ED at diagnosis had more IBD-related hospitalizations and more ED visits during follow-up. Between-center heterogeneity was high for intestinal resection in Crohn's disease but not colectomy in ulcerative colitis. Conclusion: There is variation in health services utilization among children with IBD and risk of undergoing intestinal resection in those with Crohn's disease, but not colectomy among children with ulcerative colitis, across Canadian pediatric tertiary-care centers. Improvements in clinical care pathways are needed to ensure all children have equitable and timely access to high quality care.

Health Services Utilization and Specialist Care in Pediatric Inflammatory Bowel Disease: A Multiprovince Population-Based Cohort Study.

BACKGROUND: Patterns of health services utilization among children with inflammatory bowel disease (IBD) are important to understand as the number of children with IBD continues to increase. We compared health services utilization and surgery among children diagnosed <10 years of age (Paris classification: A1a) and between 10 and <16 years of age (A1b). METHODS: Incident cases of IBD diagnosed <16 years of age were identified using validated algorithms from deterministically linked health administrative data in 5 Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario, Quebec) to conduct a retrospective cohort study. We compared the frequency of IBD-specific outpatient visits, emergency department visits, and hospitalizations across age groups (A1a vs A1b [reference]) using negative binomial regression. The risk of surgery was compared across age groups using Cox proportional hazards models. Models were adjusted for sex, rural/urban residence location, and mean neighborhood income quintile. Province-specific estimates were pooled using random-effects meta-analysis. RESULTS: Among the 1165 (65.7% Crohn's) children with IBD included in our study, there were no age differences in the frequency of hospitalizations (rate ratio [RR], 0.88; 95% confidence interval [CI], 0.74-1.06) or outpatient visits (RR, 0.95; 95% CI, 0.78-1.16). A1a children had fewer emergency department visits (RR, 0.70; 95% CI, 0.50-0.97) and were less likely to require a Crohn's-related surgery (hazard ratio, 0.49; 95% CI, 0.26-0.92). The risk of colectomy was similar among children with ulcerative colitis in both age groups (hazard ratio, 0.71; 95% CI, 0.49-1.01). CONCLUSIONS: Patterns of health services utilization are generally similar when comparing children diagnosed across age groups.

Among 1165 children with inflammatory bowel disease, health services utilization was similar for children diagnosed <10 years of age and those diagnosed ≥10 years of age, except younger children had fewer emergency department visits and Crohn's disease­related surgeries.

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.

Hospital learning curves for robot-assisted surgeries: a population-based analysis.

BACKGROUND: Robot-assisted surgery has been rapidly adopted. It is important to define the learning curve to inform credentialling requirements, training programs, identify fast and slow learners, and protect patients. This study aimed to characterize the hospital learning curve for common robot-assisted procedures. STUDY DESIGN: This cohort study, using administrative health data for Ontario, Canada, included adult patients who underwent a robot-assisted radical prostatectomy (RARP), total robotic hysterectomy (TRH), robot-assisted partial nephrectomy (RAPN), or robotic portal lobectomy using four arms (RPL-4) between 2010 and 2021. The association between cumulative hospital volume of a robot-assisted procedure and major complications was evaluated using multivariable logistic models adjusted for patient characteristics and clustering at the hospital level. RESULTS: A total of 6814 patients were included, with 5230, 543, 465, and 576 patients in the RARP, TRH, RAPN, and RPL-4 cohorts, respectively. There was no association between cumulative hospital volume and major complications. Visual inspection of learning curves demonstrated a transient worsening of outcomes followed by subsequent improvements with experience. Operative time decreased for all procedures with increasing volume and reached plateaus after approximately 300 RARPs, 75 TRHs, and 150 RPL-4s. The odds of a prolonged length of stay decreased with increasing volume for patients undergoing a RARP (OR 0.87; 95% CI 0.82-0.92) or RPL-4 (OR 0.77; 95% CI 0.68-0.87). CONCLUSION: Hospitals may adopt robot-assisted surgery without significantly increasing the risk of major complications for patients early in the learning curve and with an expectation of increasing efficiency.

Pandemic Effect on Healthcare Use and Death in Adults with Epilepsy: A Population Study.

OBJECTIVES: We conducted a population-based study using Ontario health administrative data to describe trends in healthcare utilization and mortality in adults with epilepsy during the first pandemic year (March 2020-March 2021) compared to historical data (2016-2019). We also investigated if changes in outpatient visits and diagnostic testing during the first pandemic year were associated with increased risk for hospitalizations, emergency department (ED) visits, or death. METHODS: Projected monthly visit rates (per 100,000 people) for outpatient visits, electroencephalography, magnetic resonance, computed tomography, all-cause ED visits, hospitalizations, and mortality were calculated based on historical data by fitting monthly time series autoregressive integrated moving-average models. Two-way interactions were calculated using Quasi-Poisson models. RESULTS: In adults with epilepsy during the first quarter of the pandemic, we demonstrated a reduction in all-cause outpatient visits, diagnostic testing, ED visits and hospitalizations, and a temporary increase in mortality (observed rates of 355.8 vs projected 308.8, 95% CI: 276.3-345.1). By the end of the year, outpatient visits increased (85,535.4 vs 76,620.6, 95% CI: 71,546.9-82,059.4), and most of the diagnostic test rates returned to the projected. The increase in the rate of all-cause mortality during the pandemic, compared to pre-pandemic, was greater during months with the lower frequency of diagnostic tests than months with higher frequency (interaction p-values <.0001). CONCLUSION: We described the impact of the pandemic on healthcare utilization and mortality in adults with epilepsy during the first year. We demonstrated that access to relevant diagnostic testing is likely important for this population while planning restrictions on non-urgent health services.

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.

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.

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.