Health Administrative Databases In Ontario Research Articles

Disparities in healthcare costs of people experiencing homelessness in Toronto, Canada in the post COVID-19 pandemic era: a matched cohort study

BackgroundEvidence is limited about healthcare cost disparities associated with homelessness, particularly in recent years after major policy and resource changes affecting people experiencing homelessness occurred after the onset of the COVID-19 pandemic. We estimated 1-year healthcare expenditures, overall and by type of service, among a representative sample of people experiencing homelessness in Toronto, Canada, in 2021 and 2022, and compared these to costs among matched housed and low-income housed individuals.MethodsData from individuals experiencing homelessness participating in the Ku-gaa-gii pimitizi-win cohort study were linked with Ontario health administrative databases. Participants (n = 640) were matched 1:5 by age, sex-assigned-at-birth and index month to presumed housed individuals (n = 3,200) and to low-income presumed housed individuals (n = 3,200). Groups were followed over 1 year to ascertain healthcare expenditures, overall and by healthcare type. Generalized linear models were used to assess unadjusted and adjusted mean cost ratios between groups.ResultsAverage 1-year costs were $12,209 (95% CI $9,762-$14,656) among participants experiencing homelessness compared to $1,769 ($1,453-$2,085) and $1,912 ($1,510-$2,314) among housed and low-income housed individuals. Participants experiencing homelessness had nearly seven times (6.90 [95% confidence interval [CI] 5.98–7.97]) the unadjusted mean ratio (MR) of costs as compared to housed persons. After adjustment for number of comorbidities and history of healthcare for mental health and substance use disorders, participants experiencing homelessness had nearly six times (adjusted MR 5.79 [95% CI 4.13–8.12]) the expected healthcare costs of housed individuals. The two housed groups had similar costs.ConclusionsHomelessness is associated with substantial excess healthcare costs. Programs to quickly resolve and prevent cases of homelessness are likely to better meet the health and healthcare needs of this population while being a more efficient use of public resources.

Language ability and virtual mental healthcare utilisation among immigrant and refugee youth: a population-based cohort study

Background and objectivesThe widespread adoption of virtual care during the pandemic may not have been uniform across populations, including among paediatric immigrants and refugees. We sought to examine the association...

5-α Reductase Inhibitors and Prostate Cancer Mortality

5-alpha-reductase-inhibitors (5-ARIs) are approved for treating benign prostatic hyperplasia (BPH) and have been found to reduce prostate cancer (PCa) risk by 25%. However, trials also have shown 5-ARIs to be associated with high-grade PCa. Whether 5-ARIs increase mortality among those with a diagnosis of PCa remains unclear. To determine long-term outcomes of clinically localized PCa arising in individuals taking 5-ARIs compared with nonusers. This population-based cohort study was conducted between January 2003 and October 2017. Eligible participants were men aged 65 years or older in Ontario, Canada, who developed clinically localized PCa with complete pathological abstraction from the Ontario Health Administrative Databases. Data analysis occurred from November 2017 to November 2022. 5-ARIs before PCa diagnosis. The primary outcomes were overall mortality and PCa-specific mortality. Cause-specific hazard models with inverse probability treatment weights (IPTW) were used to examine associations of 5-ARI use with mortality outcomes. Sensitivity analyses based on prediagnostic 5-ARI use, Gleason score, comorbidity, 5-ARI indication, prostate-specific antigen modeling, and statin use were also performed. The cohort included 19 938 patients with PCa. Of these, 2112 (10.6%; median [IQR] age, 74 [70-79] years) were 5-ARI users and 17 826 (89.4%; median [IQR] age, 71 [68-76] years) were nonusers. During a median (IQR) follow-up of 8.96 (6.28-12.17) years, 6053 (30.4%) died, including 1047 (5.3%) from PCa. 5-ARI use appeared to be associated with increased overall and PCa specific mortality in crude analyses; however, after IPTW, 5-ARI use was not associated with overall mortality (hazard ratio, 0.98; 95% CI, 0.90-1.07; P = .77) or PCa-specific mortality (hazard ratio, 1.02; 95% CI, 0.83-1.25; P = .84). In this population-based cohort study of 5-ARI use prior to PCa diagnosis including long-term follow-up and clinicopathologic details, prediagnostic 5-ARI use was not associated with PCa-specific or all-cause mortality. This study offers reassuring safety data for patients using 5-ARIs before PCa diagnosis for both BPH and chemopreventive reasons.

Identification of homelessness using health administrative data in Ontario, Canada following a national coding mandate: a validation study

ObjectivesConducting longitudinal health research about people experiencing homelessness poses unique challenges. Identification through administrative data permits large, cost-effective studies; however, case validity in Ontario is unknown after a 2018 Canada-wide policy change mandating homelessness coding in hospital databases. We validated case definitions for identifying homelessness using Ontario health administrative databases after introduction of this coding mandate. Study Design and SettingWe assessed 42 case definitions in a representative sample of people experiencing homelessness in Toronto (n = 640) from whom longitudinal housing history (ranging from 2018 to 2022) was obtained, and a randomly selected sample of presumably housed people (n = 128,000) in Toronto. We evaluated sensitivity, specificity, positive and negative predictive values, and positive likelihood ratios to select an optimal definition, and compared the resulting true positives against false positives and false negatives to identify potential causes of misclassification. ResultsThe optimal case definition included any homelessness indicator during a hospital-based encounter within 180 days of a period of homelessness (sensitivity = 52.9%; specificity = 99.5%). For periods of homelessness with ≥1 hospital-based healthcare encounter, the optimal case definition had greatly improved sensitivity (75.1%) while retaining excellent specificity (98.5%). Review of false positives suggested that homeless status is sometimes erroneously carried forward in healthcare databases after an individual transitioned out of homelessness. ConclusionCase definitions to identify homelessness using Ontario health administrative data exhibit moderate to good sensitivity and excellent specificity. Sensitivity has more than doubled since the implementation of a national coding mandate. Mandatory collection and reporting of homelessness information within administrative data present invaluable opportunities for advancing research on the health and healthcare needs of people experiencing homelessness.

Frailty risk assessment and impact on acute myeloid leukemia outcomes (FRAIL-AML): A population-based study from Ontario, Canada.

6506 Background: In acute myeloid leukemia (AML), treatment decisions, specifically intensive versus non-intensive approaches, depend on the clinician’s assessment of patient fitness. Frailty as a measure of fitness is a broader concept than commodities and is associated with worse outcomes in many cancers. Frailty assessment is incorporated to provide the precision to oncology treatment selections in addition to disease-related factors. The impact of frailty on outcomes in AML is not well studied. Methods: This retrospective cohort study from population-based health administrative databases in Ontario, Canada (ICES) included all patients (pts) ≥18 years diagnosed with AML between 2006 and 2021, treated within 90 days after diagnosis. Frailty was measured using McIsaacs’s frailty index (MFI)- a validated tool. Progressively increasing tertiles of MFI were categorized as fit (FT), pre-frail (PFR), or frail (FR). Treatment intensity was classified as intensive (IT) or non-intensive (NIT) based on standard practices. The primary outcome was overall survival (OS). Association of frailty with OS was measured using Cox regression separately for IT and NIT AML. Results: Out of 5450 pts, with a median age of 65 (IQR 54-74), 55.8% were males and 44.2% were females. 65% (n=3543) received IT, out of which 29.4% and 35.5% pts were FR and PFR respectively. Remaining 35% (n=1907) received NIT, with 41.1% and 32.3% pts being FR and PFR. Median overall survival in months (OS, 95% CI) for the entire group, IT, and NIT were 12.5 (12.0-13.2), 16.7 (15.7-18.2), and 7.6 (7.0-8.2), respectively. OS (table) was notably lower in FR pts compared to fit pts (p<0.0001) in both IT and NIT. Univariate and multivariate analyses identified frailty, advanced age, and previous non-AML malignancy as risk factors associated with worse OS in both IT and NIT groups (table). Conclusions: Higher frailty is independently associated with worse OS in AML pts after adjusting for advanced age. A substantial proportion of AML pts in both IT and NIT groups exhibit a mismatch in treatment intensity assignments based on their frailty status, with about 30 % FR pts receiving IT and over 25 % FT pts receiving NIT. This study sheds light on the need for frailty evaluations using standardized tools to optimize treatment decisions in AML pts. [Table: see text]

Association between opioid use disorder and palliative care: a cohort study using linked health administrative data in Ontario, Canada.

People with opioid use disorder (OUD) are at risk of premature death and can benefit from palliative care. We sought to compare palliative care provision for decedents with and without OUD. We conducted a cohort study using health administrative databases in Ontario, Canada, to identify people who died between July 1, 2015, and Dec. 31, 2021. The exposure was OUD, defined as having emergency department visits, hospital admissions, or pharmacologic treatments suggestive of OUD within 3 years of death. Our primary outcome was receipt of 1 or more palliative care services during the last 90 days before death. Secondary outcomes included setting, initiation, and intensity of palliative care. We conducted a secondary analysis excluding sudden deaths (e.g., opioid toxicity, injury). Of 679 840 decedents, 11 200 (1.6%) had OUD. Compared with people without OUD, those with OUD died at a younger age and were more likely to live in neighbourhoods with high marginalization indices. We found people with OUD were less likely to receive palliative care at the end of their lives (adjusted relative risk [RR] 0.84, 95% confidence interval [CI] 0.82-0.86), but this difference did not exist after excluding people who died suddenly (adjusted RR 0.99, 95% CI 0.96-1.01). People with OUD were less likely to receive palliative care in clinics and their homes regardless of cause of death. Opioid use disorder can be a chronic, life-limiting illness, and people with OUD are less likely to receive palliative care in communities during the 90 days before death. Health care providers should receive training in palliative care and addiction medicine to support people with OUD.

Measuring waning protection from seasonal influenza vaccination during nine influenza seasons, Ontario, Canada, 2010/11 to 2018/19.

BackgroundWaning immunity from seasonal influenza vaccination can cause suboptimal protection during peak influenza activity. However, vaccine effectiveness studies assessing waning immunity using vaccinated and unvaccinated individuals are subject to biases.AimWe examined the association between time since vaccination and laboratory-confirmed influenza to assess the change in influenza vaccine protection over time.MethodsUsing linked laboratory and health administrative databases in Ontario, Canada, we identified community-dwelling individuals aged ≥ 6 months who received an influenza vaccine before being tested for influenza by RT-PCR during the 2010/11 to 2018/19 influenza seasons. We estimated the adjusted odds ratio (aOR) for laboratory-confirmed influenza by time since vaccination (categorised into intervals) and for every 28 days.ResultsThere were 53,065 individuals who were vaccinated before testing for influenza, with 10,264 (19%) influenza-positive cases. The odds of influenza increased from 1.05 (95% CI: 0.91-1.22) at 42-69 days after vaccination and peaked at 1.27 (95% CI: 1.04-1.55) at 126-153 days when compared with the reference interval (14-41 days). This corresponded to 1.09-times increased odds of influenza every 28 days (aOR = 1.09; 95% CI: 1.04-1.15). Individuals aged 18-64 years showed the greatest decline in protection against influenza A(H1N1) (aORper 28 days = 1.26; 95% CI: 0.97-1.64), whereas for individuals aged ≥ 65 years, it was against influenza A(H3N2) (aORper 28 days = 1.20; 95% CI: 1.08-1.33). We did not observe evidence of waning vaccine protection for individuals aged < 18 years.ConclusionsInfluenza vaccine protection wanes during an influenza season. Understanding the optimal timing of vaccination could ensure robust protection during seasonal influenza activity.

Association of a calcium channel blocker and diuretic prescribing cascade with adverse events: A population-based cohort study.

Prescribing cascades occur when a drug adverse event is misinterpreted as a new medical condition and a second, potentially unnecessary drug, is prescribed to treat the adverse event. The population-level consequences of prescribing cascades remain unknown. This population-based cohort study used linked health administrative databases in Ontario, Canada. The study included community-dwelling adults, 66 years of age or older with hypertension and no history of heart failure (HF) or diuretic use in the prior year, newly dispensed a calcium channel blocker (CCB). Individuals subsequently dispensed a diuretic within 90 days of incident CCB dispensing were classified as the prescribing cascade group, and compared to those not dispensed a diuretic, classified as the non-prescribing cascade group. Those with and without a prescribing cascade were matched one-to-one on the propensity score and sex. The primary outcome was a serious adverse event (SAE), which was the composite of emergency room visits and hospitalizations in the 90-day follow-up period. We estimated hazard ratios (HRs) with 95% confidence intervals (CI) for SAE using an Andersen-Gill recurrent events regression model. Among 39,347 older adults with hypertension and no history of HF who were newly dispensed a CCB, 1881 (4.8%) had a new diuretic dispensed within 90 days after CCB initiation. Compared to the non-prescribing cascade group, those in the prescribing cascade group had higher rates of SAEs (HR: 1.21, 95% CI: 1.02-1.43). The CCB-diuretic prescribing cascade was associated with an increased rate of SAEs, suggesting harm beyond prescribing a second drug therapy. Our study raises awareness of the downstream impact of the CCB-diuretic prescribing cascade at a population level and provides an opportunity for clinicians who identify this prescribing cascade to review their patients' medications to determine if they can be optimized.

Utilization of physician mental health services by birthing parents with young children during the COVID-19 pandemic: a population-based, repeated cross-sectional study.

The COVID-19 pandemic and nonpharmaceutical interventions that reduced the spread of infection had impacts on social interaction, schooling and employment. Concerns have been raised about the impact of these disruptions on the mental health of high-risk groups, including birthing parents of young children. This population-based, repeated cross-sectional study used health administrative databases in Ontario, Canada, to link children to birth parents and to measure subsequent mental health visits of birthing parents of younger (age 0-5 yr) and school-aged (6-12 yr) children. We used a repeated cross-sectional study design to estimate expected rates for visits to physicians for mental health diagnoses, based on prepandemic trends (March 2016-February 2020), and to compare those to observed visit rates during the March 2020-November 2021 period of the pandemic. We identified 2 cohorts: 986 870 birthing parents of younger children and 1 012 997 birthing parents of school-aged children. In both cohorts, observed visit rates were higher than expected in the June 2020-August 2020 quarter (incidence rate ratio [IRR] 1.13, 95% confidence interval [CI] 1.10-1.16; and IRR 1.10, 95% CI 1.07-1.13, respectively), peaked in December 2020-February 2021 (IRR 1.24, 95% CI 1.20-1.27; and IRR 1.20, 95% CI 1.16-1.23) and remained higher than expected in September 2021-November 2021 (IRR 1.12, 95% CI 1.08-1.16; and IRR 1.09, 95% CI 1.06-1.13). The increases were driven mostly by visits for mood and anxiety disorders, and trends in increases were similar across physician type, birthing-parent age and deprivation quintile. The COVID-19 pandemic was associated with increased mental health visits for parents of young children. This raises concerns about mental health impacts and highlights the need to address these concerns.

Trends in infection-related and infection-unrelated cancer incidence among people with and without HIV infection in Ontario, Canada, 1996-2020: a population-based matched cohort study using health administrative data.

People with HIV infection are at higher risk for certain cancers than the general population. We compared trends in infection-related and infection-unrelated cancers among people with and without HIV infection. We conducted a retrospective population-based matched cohort study of adults with and without HIV infection using linked health administrative databases in Ontario, Canada. Participants were matched on birth year, sex, census division (rurality), neighbourhood income quintile and region of birth. We followed participants from cohort entry until the earliest of date of cancer diagnosis, date of death, Nov. 1, 2020, or date of loss to follow-up. Incident cancers identified from Jan. 1, 1996, to Nov. 1, 2020, were categorized as infection-related or-unrelated. We examined calendar periods 1996-2003, 2004-2011 and 2012-2020, corresponding to the early combination antiretroviral therapy (cART), established cART and contemporary cART eras, respectively. We used competing risk analyses to examine trends in cumulative incidence by calendar period, age and sex, and cause-specific hazard ratios (HRs). We matched 20 304 people with HIV infection to 20 304 people without HIV infection. A total of 2437 cancers were diagnosed, 1534 (62.9%) among infected people and 903 (37.0%) among uninfected people. The risk of infection-related cancer by age 65 years for people with HIV infection decreased from 19.0% (95% confidence interval [CI] 15.6%-22.3%) in 1996-2011 to 10.0% (95% CI 7.9%-12.1%) in 2012-2020. Compared to uninfected people, those with HIV infection had similar HRs of infection-unrelated cancer but increased rates of infection-related cancer, particularly among younger age groups (25.1 [95% CI 13.2-47.4] v. 1.9 [95% CI 1.0-3.7] for age 18-39 yr v. ≥ 70 yr); these trends were consistent when examined by sex.Interpretation: We observed significantly higher rates of infection-related, but not infection-unrelated, cancer among people with HIV infection than among uninfected people. The elevated rate of infection-related cancer in 2012-2020 highlights the importance of early and sustained antiretroviral therapy along with cancer screening and prevention measures.

Self-Harm Events and Suicide Deaths Among Autistic Individuals in Ontario, Canada

Reasons for elevated suicide risks among autistic people are unclear, with insufficient population-based research on sex-specific patterns to inform tailored prevention and intervention. To examine sex-stratified rates of self-harm events and suicide death among autistic individuals compared with nonautistic individuals, as well as the associated sociodemographic and clinical risk factors. This population-based matched-cohort study using linked health administrative databases in Ontario, Canada included all individuals with physician-recorded autism diagnoses from April 1, 1988, to March 31, 2018, each matched on age and sex to 4 nonautistic individuals from the general population. Self-harm events resulting in emergency health care from April 1, 2005, to December 31, 2020, were examined for one cohort, and death by suicide and other causes from April 1, 1993, to December 31, 2018, were examined for another cohort. Statistical analyses were conducted between October 2021 and June 2023. Physician-recorded autism diagnoses from 1988 to 2018 from health administrative databases. Autistic and nonautistic individuals who were sex stratified a priori were compared using Andersen-Gill recurrent event models on self-harm events, and cause-specific competing risk models on death by suicide or other causes. Neighborhood-level income and rurality indices, and individual-level broad diagnostic categories of intellectual disabilities, mood and anxiety disorders, schizophrenia spectrum disorders, substance use disorders, and personality disorders were covariates. For self-harm events (cohort, 379 630 individuals; median age at maximum follow-up, 20 years [IQR, 15-28 years]; median age of first autism diagnosis claim for autistic individuals, 9 years [IQR, 4-15 years]; 19 800 autistic females, 56 126 autistic males 79 200 nonautistic females, and 224 504 nonautistic males), among both sexes, autism diagnoses had independent associations with self-harm events (females: relative rate, 1.83; 95% CI, 1.61-2.08; males: relative rate, 1.47; 95% CI, 1.28-1.69) after accounting for income, rurality, intellectual disabilities, and psychiatric diagnoses. For suicide death (cohort, 334 690 individuals; median age at maximum follow-up, 19 years [IQR, 14-27 years]; median age of first autism diagnosis claim for autistic individuals, 10 years [IQR, 5-16 years]; 17 982 autistic females, 48 956 autistic males, 71 928 nonautistic females, 195 824 nonautistic males), there was a significantly higher crude hazard ratio among autistic females (1.98; 95% CI, 1.11-3.56) and a nonsignificantly higher crude hazard ratio among autistic males (1.34; 95% CI, 0.99-1.82); the increased risks were associated with psychiatric diagnoses. This cohort study suggests that autistic individuals experienced increased risks of self-harm events and suicide death. Psychiatric diagnoses were significantly associated with the increased risks among both sexes, especially for suicide death, and in partially sex-unique ways. Autism-tailored and autism-informed clinical and social support to reduce suicide risks should consider multifactorial mechanisms, with a particular focus on the prevention and timely treatment of psychiatric illnesses.

Evaluating the Impact of Statin Use on Influenza Vaccine Effectiveness and Influenza Infection in Older Adults.

Older adults are recommended to receive influenza vaccination annually, and many use statins. Statins have immunomodulatory properties that might modify influenza vaccine effectiveness (VE) and alter influenza infection risk. Using the test-negative design and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against laboratory-confirmed influenza among community-dwelling statin users and nonusers aged ≥66 years during the 2010-2011 to 2018-2019 influenza seasons. We also estimated the odds ratio for influenza infection comparing statin users and nonusers by vaccination status. Among persons tested for influenza across the 9 seasons, 54 243 had continuous statin exposure before testing and 48 469 were deemed unexposed. The VE against laboratory-confirmed influenza was similar between statin users and nonusers (17% [95% confidence interval, 13%-20%] and 17% [13%-21%] respectively; test for interaction, P = .87). In both vaccinated and unvaccinated persons, statin users had higher odds of laboratory-confirmed influenza than nonusers (odds ratios for vaccinated and unvaccinated persons 1.15 [95% confidence interval, 1.10-1.21] and 1.15 [1.10-1.20], respectively). These findings were consistent by mean daily dose and statin type. VE did not differ between users and nonusers of other cardiovascular drugs, except for β-blockers. We did not observe that vaccinated and unvaccinated users of these drugs had increased odds of influenza, except for unvaccinated β-blocker users. Influenza VE did not differ between statin users and nonusers. Statin use was associated with increased odds of laboratory-confirmed influenza in vaccinated and unvaccinated persons, but these associations might be affected by residual confounding.

Perinatal and pediatric outcomes associated with the use of fertility treatment: a population-based retrospective cohort study in Ontario, Canada

BackgroundAround 2% of births in Ontario, Canada involve the use of assisted reproductive technology (ART), and it is rising due to the implementation of a publicly funded ART program in 2016. To better understand the impact of fertility treatments, we assessed perinatal and pediatric health outcomes associated with ART, hormonal treatments, and artificial insemination compared with spontaneously conceived births.MethodsThis population-based retrospective cohort study was conducted using provincial birth registry data linked with fertility registry and health administrative databases in Ontario, Canada. Live births and stillbirths from January 2013 to July 2016 were included and followed to age one. The risks of adverse pregnancy, birth and infant health outcomes were assessed by conception method (spontaneous conception, ART – in vitro fertilization and non-ART – ovulation induction, intra-uterine or vaginal insemination) using risk ratios and incidence rate ratios with 95% confidence intervals (CI). Propensity score weighting using a generalized boosted model was applied to adjust for confounding.Result(s)Of 177,901 births with a median gestation age of 39 weeks (IQR 38.0–40.0), 3,457 (1.9%) were conceived via ART, and 3,511 (2.0%) via non-ART treatments. There were increased risks (adjusted risk ratio [95% CI]) of cesarean delivery (ART: 1.44 [1.42–1.47]; non-ART: 1.09 [1.07–1.11]), preterm birth (ART: 2.06 [1.98–2.14]; non-ART: 1.85 [1.79–1.91]), very preterm birth (ART: 2.99 [2.75–3.25]; non-ART: 1.89 [1.67–2.13]), 5-min Apgar < 7 (ART: 1.28 [1.16–1.42]; non-ART: 1.62 [1.45–1.81]), and composite neonatal adverse outcome indicator (ART: 1.61 [1.55–1.68]; non-ART: 1.29 [1.25–1.34]). Infants born after fertility treatments had increased risk of admission to neonatal intensive care unit (ART: 1.98 [1.84–2.13]; non-ART: 1.59 [1.51–1.67]) and prolonged birth admission (≥ 3 days) (ART: 1.60 [1.54–1.65]; non-ART: 1.42 [1.39–1.45]). The rate of emergency and in-hospital health services use within the first year was significantly increased for both exposure groups and remained elevated when limiting analyses to term singletons.Conclusion(s)Fertility treatments were associated with increased risks of adverse outcomes; however, the overall magnitude of risks was lower for infants conceived via non-ART treatments.

Cardiovascular outcomes in children with Kawasaki disease: a population-based cohort study.

The risk of cardiovascular events after Kawasaki disease (KD) remains uncertain. Our objective was to determine the risk of cardiovascular events and mortality after KD. Population-based retrospective cohort study using Ontario health administrative databases (0-18 years; 1995-2018). pediatric KD hospitalizations. Each case was matched to 100 non-exposed controls. major adverse cardiac events (MACE; cardiovascular death, myocardial infarction, or stroke composite). composite cardiovascular events and mortality. We determined incidence rates and adjusted hazard ratios (aHR) using multivariable Cox models. Among 4597 KD survivors, 79 (1.7%) experienced MACE, 632 (13.8%) composite cardiovascular events, and 9 (0.2%) died during 11-year median follow-up. The most frequent cardiovascular events among KD survivors were ischemic heart disease (4.6 events/1000 person-years) and arrhythmias (4.5/1000 person-years). KD survivors were at increased risk of MACE between 0-1 and 5-10 years, and composite cardiovascular events at all time periods post-discharge. KD survivors had a lower mortality risk throughout follow-up (aHR 0.36, 95% CI 0.19-0.70). KD survivors are at increased risk of post-discharge cardiovascular events but have a lower risk of death, which justifies enhanced cardiovascular disease surveillance in these patients. Among 4597 Kawasaki disease (KD) survivors, 79 (1.7%) experienced major adverse cardiac events (MACE) and 632 (13.8%) had composite cardiovascular events during 11-year median follow-up. KD survivors had significantly higher risks of post-discharge MACE and cardiovascular events versus non-exposed children. Only nine KD survivors (0.2%) died during follow-up, and the risk of mortality was significantly lower among KD survivors versus non-exposed children. Childhood KD survivors should receive preventative counseling and cardiovascular surveillance, aiming to mitigate adult cardiovascular disease.

Pregnancy Outcomes Following Medical Versus Surgical Treatment of Ectopic Pregnancy in Ontario

<h3>Study Objective</h3> To compare the live birth rate following medical versus surgical treatment of tubal ectopic pregnancy (TEP) in Ontario. Secondary outcome was the recurrence of TEP. <h3>Design</h3> This is a retrospective population-based cohort study using validated Ontario health administration data. <h3>Setting</h3> Ontario, Canada. <h3>Patients or Participants</h3> This study included 17, 090 patients treated for TEP in Ontario, Canada between January 1, 2008, and December 31, 2019. <h3>Interventions</h3> Medical management with methotrexate versus surgical management with laparoscopic salpingectomy or salpingostomy. <h3>Measurements and Main Results</h3> Type of treatment was determined using diagnostic and billing codes from Ontario health administrative databases. Of the 17,090 cases of TEP In Ontario, 8,204 were treated medically, 8,737 surgically and 149 received both. Baseline characteristics were compared using standardized differences. Patients treated with medical management were slightly older at the time of first pregnancy/delivery and less parous at time of the ectopic pregnancy, with more patients treated surgically having a history of PID. Patients receiving medical management had a 51.6% future live birth rate, compared to 45.1% with surgical management and a recurrent TEP rate of 7.4% compared to 6.4% respectively. After controlling for age at first TEP, previous TEP, PID, Endometriosis, previous pelvic surgery, parity, comorbidity score and socioeconomic score, multivariable regression analysis demonstrated that patients receiving medical management had a greater odds of future live birth rate compared to surgical management (OR 1.29, p<0.001). The repeat ectopic pregnancy rate was also higher with medical management compared to surgical (OR 1.2, P=0.004). <h3>Conclusion</h3> Women treated medically for TEP are at significantly increased odds to have a future live birth, but more likely to have a recurrent TEP, compared to women treated surgically.

Epilepsy Risk Following Bariatric Surgery for Weight Loss.

A previous study reported finding that epilepsy risk is elevated after bariatric surgery for weight loss; however, this association has not been adequately explored. Our objectives were to (1) estimate the risk of epilepsy after bariatric surgery for weight loss relative to a nonsurgical cohort of patients with an obesity diagnosis and (2) identify epilepsy risk factors among bariatric surgery recipients. We conducted a population-based retrospective cohort study using linked health administrative databases in Ontario, Canada. Participants were accrued between July 1, 2010, and December 31, 2016, and followed until December 31, 2019. All Ontario residents aged 18 years and older who had bariatric surgery during the accrual period were eligible for inclusion in our exposed cohort. Patients hospitalized with a diagnosis of obesity and who did not have bariatric surgery during the accrual period were eligible for inclusion in our unexposed cohort. We excluded patients with a history of seizures, epilepsy, various seizure or epilepsy risk factors, psychiatric disorders, or drug or alcohol abuse/dependence. In our primary analysis, we used inverse probability of treatment weighting to control for confounding. A marginal Cox proportional hazards model was then used to estimate the risk of epilepsy associated with bariatric surgery. A Cox model was also used to identify epilepsy risk factors among exposed participants. The final sample included 16,958 exposed participants and 622,514 unexposed participants. After inverse probability of treatment weighting, the estimated rates of epilepsy were 50.1 and 34.1 per 100,000 person-years among those who did and did not have bariatric surgery, respectively. The hazard ratio for developing epilepsy after bariatric surgery was 1.45 (95% CI = 1.35, 1.56). Among participants who received bariatric surgery, stroke during follow-up increased epilepsy risk (HR = 14.03, 95% CI = 4.26, 46.25). In this study, we found that patients with a history of bariatric surgery were at increased risk of developing epilepsy. These findings suggest that epilepsy is a long-term risk associated with bariatric surgery for weight loss.

Primary Care Physician Use and Frequency of Visits Among Physicians in Ontario, Canada

Maintaining a healthy physician workforce includes the routine use of primary care physician (PCP) services; however, physicians may face barriers to attaining formal care. To analyze access to and frequency of visits to PCPs among physicians compared with nonphysicians. This population-based, retrospective cohort study used registration data from the College of Physicians and Surgeons of Ontario, Canada, from January 1, 1990, to March 31, 2018. Data for all newly practicing physicians as of March 31, 2018, were linked to Ontario health administrative databases. Data were analyzed from August 25, 2020, to August 6, 2021. The main outcomes were enrollment in a PCP practice and visits with a PCP. Generalized estimating equations compared primary care visits between physicians and nonphysicians, matched 1:5 based on age, sex, neighborhood income quintile, and health region. Among 19 581 physicians (mean [SD] age, 43.99 [8.94] years; 53.27% male) matched to 97 905 nonphysicians, physicians were less likely to be enrolled with a PCP than were nonphysicians (81.8% vs 86.4%; absolute difference, 4.6%; adjusted odds ratio [OR], 0.75; 95% CI, 0.72-0.79) and had fewer primary care visits during the preceding 2 years (median [IQR], 2 [0-4] vs 4 [1-7]; adjusted relative rate ratio [RRR], 0.59; 95% CI, 0.58-0.60). Physicians aged 40 years or older and male physicians were less likely to be rostered (ages 40-44 years: OR, 0.70 [95% CI, 0.64-0.77]; male: OR, 0.60 [95% CI, 0.57-0.63]) and more likely to have a lower frequency of PCP visits (ages 40-44 years: RRR, 0.53 [95% CI, 0.51-0.56]; male: RRR, 0.50 [95% CI, 0.50-0.51]) compared with nonphysicians. In this retrospective cohort study, enrollment with a PCP practice and frequency of visits were lower among physicians compared with a matched general population of nonphysicians. Individual, system, and medical cultural factors associated with these results need to be better understood so that physicians can take better care of themselves and their patients.

Analysis of Rates of Brain Metastases and Association With Breast Cancer Subtypes in Ontario, Canada

Approximately 1 in 7 patients with metastatic breast cancer (MBC) will receive radiotherapy for brain metastases (BRM). Significant differences in cumulative incidence of BRM by breast cancer subtype may inform future BRM screening protocols. To describe cumulative incidence of BRM among patients with de novo MBC. In this population-based cohort study, population health administrative databases in Ontario, Canada, held at the ICES were used to identify patients diagnosed with de novo MBC between 2009 and 2018. Given that a code for BRM does not exist within ICES, we analyzed the incidence of radiotherapy for BRM. The median (IQR) follow-up was 19.3 (6.2-39.5) months. A total of 100 747 patients with a new diagnosis of breast cancer between January 2009 and December 2018 were identified. Of these patients, 17 955 were excluded because they had previous or subsequent malignant neoplasms, 583 were excluded because they were younger than 18 years, 974 were excluded because there was an invalid Ontario Health Insurance Plan number or a date of death on or before the index date. Among 81 235 remaining patients, 3916 were identified as having de novo MBC. Treatment with radiotherapy for breast cancer BRM. Cumulative incidence of radiotherapy for BRM accounting for the competing risk of death, and time from MBC diagnosis to brain radiotherapy. Kaplan-Meier analyses were performed for time-to-event end points. Logistic regression was used to account for confounding variables. Among 3916 patients with MBC, 1215 (31.0%) had HR-positive/ERBB2 (formerly HER2)-negative cancer, 310 (7.9%) had ERBB2-positive/HR-positive cancer, 200 (5.1%) had ERBB2-positive/HR-negative cancer, 258 (6.6%) had TNBC, and the remaining 1933 patients (49.4%) had an unknown breast cancer subtype. The median (IQR) age at diagnosis was 63 (52-75). A total of 549 (14.0%) underwent stereotactic radiosurgery or whole brain radiotherapy for breast cancer BRM. Cumulative incidence of BRM was higher among patients with ERBB2-positive/HR-negative breast cancer (34.7%), ERBB2-positive/HR-positive breast cancer (28.1%), and triple-negative breast cancer (21.9%) compared to those with HR-positive/ERBB2-negative breast cancer (12.1%). The median (IQR) time from MBC diagnosis to brain radiotherapy ranged from 7.5 (2.3-17.4) months for patients with TNBC to 19.8 (12.2-35.1) months for those with ERBB2-positive/HR-positive breast cancer. Incidence and time to development of BRM vary significantly by breast cancer subtype. A better understanding of the biology of intracranial metastatic disease may help inform potential screening programs or preventative interventions.

Cancer incidence and stage at diagnosis among people with recent-onset psychotic disorders: A retrospective cohort study using health administrative data from Ontario, Canada.

Prior evidence on the relative risk of cancer among people with psychotic disorders is equivocal. The objective of this study was to compare incidence and stage at diagnosis of cancer for people with psychotic disorders relative to the general population. We constructed a retrospective cohort of people with a first diagnosis of non-affective psychotic disorder and a comparison group from the general population using linked health administrative databases in Ontario, Canada. The cohort was followed for incident diagnoses of cancer over a 25-year period. We used Poisson and logistic regression models to compare cancer incidence and stage at diagnosis between people with psychotic disorders and the comparison group, adjusting for confounding factors. People with psychotic disorders had an 8.6% higher incidence (IRR=1.09, 95%CI=1.05,1.12) of cancer overall relative to the comparison group, with effect modification by sex and substantial variation across cancer sites. People with psychotic disorders also had 23% greater odds (OR=1.23, 95%CI=1.13,1.34) of being diagnosed with more advanced stage cancer relative to the comparison group. We found evidence of elevated cancer incidence in people with non-affective psychotic disorders relative to the general population. The higher odds of more advanced stage cancer diagnoses in people with psychotic disorders represents an opportunity to improve patient participation in recommended cancer screening, as well as timely access to services for cancer diagnosis and treatment. Future research should examine confounding effects of lifestyle factors and antipsychotic medications on the risk of developing cancer among people with psychotic disorders.

Suicide and Self-Harm Among Physicians in Ontario, Canada.

Studies of occupation-associated suicide suggest physicians may be at a higher risk of suicide compared to nonphysicians. We set out to assess the risk of suicide and self-harm among physicians and compare it to nonphysicians. We conducted a population-based, retrospective cohort study using registration data from the College of Physicians and Surgeons of Ontario from 1990 to 2016 with a follow-up to 2017, linked to Ontario health administrative databases. Using age- and sex-standardized rates and inverse probability-weighted, cause-specific hazards regression models, we compared rates of suicide, self-harm, and a composite of either event among all newly registered physicians to nonphysician controls. Among 35,989 physicians and 6,585,197 nonphysicians, unadjusted suicide events (0.07% vs. 0.11%) and rates (9.44 vs. 11.55 per 100,000 person-years) were similar. Weighted analyses found a hazard ratio of 1.05 (95% confidence interval: 0.69 to 1.60). Self-harm requiring health care was lower among physicians (0.22% vs. 0.46%; hazard ratio: 0.65, 95% confidence interval: 0.52 to 0.82), as was the composite of suicide or self-harm (hazard ratio: 0.70, 95% confidence interval: 0.57 to 0.86). The composite of suicide or self-harm was associated with a history of a mood or anxiety disorder (odds ratio: 2.84, 95% confidence interval: 1.17 to 6.87), an outpatient mental health visit in the past year (odds ratio: 3.08, 95% confidence interval: 1.34 to 7.10) and psychiatry visit in the preceding year (odds ratio: 3.87, 95% confidence interval: 1.67 to 8.95). Physicians in Ontario are at a similar risk of suicide deaths and a lower risk of self-harm requiring health care relative to nonphysicians. Risk factors associated with suicide or self-harm may help inform prevention programs.