The impact of referring hospital resources on interfacility overtriage: A population-based analysis.

BACKGROUND: Nearly half of patients transferred from non-trauma to trauma centres have minor injuries. The transfer of patients with minor injuries to trauma centres is not associated with any known patient benefit and represents an opportunity to reduce healthcare costs and improve patient experience. In this study, we evaluated the relationship between hospital resources and overtriage, with the objective of identifying targets for system-level intervention. METHODS: We conducted a population-based cohort study of adults, age ≥ 16, presenting with minor injuries to non-trauma centres in Ontario, Canada (2009-2020). The primary outcome was overtriage, defined as transfer to a trauma centre. Hierarchical logistic regression was used to evaluate the association between hospital resources and a patient's likelihood of being overtriaged, adjusting for case-mix. RESULTS: amongst 165,302 patients with minor injuries, 15,641 (9.5 %) were transferred to a trauma centre (overtriage). Presence of a CT scanner, surgical support, or intensive care unit had no impact on a patient's likelihood of overtriage. Relative to community hospitals, presentation to a teaching hospital was independently associated with greater odds of overtriage (OR 2.97, 95 % CI: 1.26-7.00). Accounting for case-mix and resources, the median difference in a patient's odds of overtriage varied 3.7-fold across non-trauma centres (MOR 3.76). CONCLUSIONS: There is significant variability in overtriage across non-trauma centres, even after adjusting for case-mix and hospital resources. These finding suggests that some centres have developed processes to minimize overtriage independent of available resources. Broad implementation of these processes may represent an opportunity for system-wide quality improvement.

Internal and external validation of an updated ICD-10-CA to AIS-2005 update 2008 algorithm.

BACKGROUND: Administrative data are a powerful tool for population-level trauma research but lack the trauma-specific diagnostic and injury severity codes needed for risk-adjusted comparative analyses. The objective of this study was to validate an algorithm to derive Abbreviated Injury Scale (AIS-2005 update 2008) severity scores from Canadian International Classification of Diseases (ICD-10-CA) diagnostic codes in administrative data. METHODS: This was a retrospective cohort study using data from the 2009 to 2017 Ontario Trauma Registry for the internal validation of the algorithm. This registry includes all patients treated at a trauma center who sustained a moderate or severe injury or were assessed by a trauma team. It contains both ICD-10-CA codes and injury scores assigned by expert abstractors. We used Cohen's kappa (𝜅) coefficient to compare AIS-2005 Update 2008 scores assigned by expert abstractors to those derived using the algorithm and the intraclass correlation coefficient to compare assigned and derived Injury Severity Scores. Sensitivity and specificity for detection of a severe injury (AIS score, ≥ 3) were then calculated. For the external validation of the algorithm, we used administration data to identify adults who either died in an emergency department or were admitted to hospital in Ontario secondary to a traumatic injury (2009-2017). Logistic regression was used to evaluate the discriminative ability and calibration of the algorithm. RESULTS: Of 41,869 patients in the Ontario Trauma Registry, 41,793 (99.8%) had at least one diagnosis matched to the algorithm. Evaluation of AIS scores assigned by expert abstractors and those derived using the algorithm demonstrated a high degree of agreement in identification of patients with at least one severe injury (𝜅 = 0.75; 95% confidence interval [CI], 0.74-0.76). Likewise, algorithm-derived scores had a strong ability to rule in or out injury with AIS ≥ 3 (specificity, 78.5%; 95% CI, 77.7-79.4; sensitivity, 95.1; 95% CI, 94.8-95.3). There was strong correlation between expert abstractor-assigned and crosswalk-derived Injury Severity Score (intraclass correlation coefficient, 0.80; 95% CI, 0.80-0.81). Among the 130,542 patients identified using administrative data, the algorithm retained its discriminative properties. CONCLUSION: Our ICD-10-CA to AIS-2005 update 2008 algorithm produces reliable estimates of injury severity and retains its discriminative properties with administrative data. Our findings suggest that this algorithm can be used for risk adjustment of injury outcomes when using population-based administrative data. LEVEL OF EVIDENCE: Diagnostic Tests/Criteria; Level II.

The impact of the early COVID-19 pandemic on healthcare system resource use and costs in two provinces in Canada: An interrupted time series analysis.

INTRODUCTION: The aim of our study was to assess the initial impact of COVID-19 on total publicly-funded direct healthcare costs and health services use in two Canadian provinces, Ontario and British Columbia (BC). METHODS: This retrospective repeated cross-sectional study used population-based administrative datasets, linked within each province, from January 1, 2018 to December 27, 2020. Interrupted time series analysis was used to estimate changes in the level and trends of weekly resource use and costs, with March 16-22, 2020 as the first pandemic week. Also, in each week of 2020, we identified cases with their first positive SARS-CoV-2 test and estimated their healthcare costs until death or December 27, 2020. RESULTS: The resources with the largest level declines (95% confidence interval) in use in the first pandemic week compared to the previous week were physician services [Ontario: -43% (-49%,-37%); BC: -24% (-30%,-19%) (both p<0.001)] and emergency department visits [Ontario: -41% (-47%,-35%); BC: -29% (-35%,-23%) (both p<0.001)]. Hospital admissions declined by 27% (-32%,-23%) in Ontario and 21% (-26%,-16%) in BC (both p<0.001). Resource use subsequently rose but did not return to pre-pandemic levels. Only home care and dialysis clinic visits did not significantly decrease compared to pre-pandemic. Costs for COVID-19 cases represented 1.3% and 0.7% of total direct healthcare costs in 2020 in Ontario and BC, respectively. CONCLUSIONS: Reduced utilization of healthcare services in the overall population outweighed utilization by COVID-19 patients in 2020. Meeting the needs of all patients across all services is essential to maintain resilient healthcare systems.

Changes in the Initiation of Antipsychotics and Trazodone Over Time: A Cohort Study of New Admissions to Nursing Homes in Ontario, Canada.

OBJECTIVES: To investigate whether trazodone is being initiated in lieu of antipsychotics following antipsychotic reduction efforts, this study described changes in medication initiation over time. METHODS: We conducted a retrospective cohort study of new admissions to nursing homes in Ontario, Canada between April 2010 and December 2019 using health administrative data (N = 61,068). The initiation of antipsychotic and trazodone use was compared by year of admission using discrete time survival analysis and stratified by history of dementia. RESULTS: Relative to residents admitted in 2014, antipsychotic initiation significantly decreased in later years (e.g., 2017 admission year hazard odds ratio [HOR2017]=0.72 [95% confidence interval (95%CI)=0.62-0.82]) while trazodone initiation modestly increased (e.g., HOR2017=1.09 [95%CI=0.98-1.21]). The relative increase in trazodone initiation was larger among residents with dementia (e.g., HOR2017Dem =1.22 [95%CI=1.07-1.39]). CONCLUSIONS: Differences in which medications were started following nursing home admission were observed and suggest trazodone may be initiated in lieu of antipsychotics.

Variation and Correlation of Potential Unintended Consequences of Antipsychotic Reduction in Ontario Nursing Homes Over Time.

BACKGROUND: Potentially inappropriate antipsychotic use has declined in nursing homes over the past decade; however, increases in the documentation of relevant clinical indications (eg, delusions) and the use of other psychotropic medications have raised concerns about diagnosis upcoding and medication substitution. Few studies have examined how these trends over time vary across and within nursing homes, information that may help to support antipsychotic reduction efforts. OBJECTIVE: To jointly model facility-level time trends in potentially inappropriate antipsychotic use, antidepressant use, and the indications used to define appropriate antipsychotic use. RESEARCH DESIGN: We conducted a repeated cross-sectional study of all nursing homes in Ontario, Canada between April 1, 2010 and December 31, 2019 using linked health administrative data (N=649). Each nursing home's quarterly prevalence of potentially inappropriate antipsychotic use, antidepressant use, and relevant indications were measured as outcome variables. With time as the independent variable, multivariate random effects models jointly estimated time trends for each outcome across nursing homes and the correlations between time trends within nursing homes. RESULTS: We observed notable variations in the time trends for each outcome across nursing homes, especially for the relevant indications. Within facilities, we found no correlation between time trends for potentially inappropriate antipsychotic and antidepressant use ( r =-0.0160), but a strong negative correlation between time trends for potentially inappropriate antipsychotic use and relevant indications ( r =-0.5036). CONCLUSIONS: Nursing homes with greater reductions in potentially inappropriate antipsychotics tended to show greater increases in the indications used to define appropriate antipsychotic use-possibly leading to unmonitored use of antipsychotics.

A population-based study of the direct longitudinal health care costs of upper extremity trauma in patients aged 18-65 years.

BACKGROUND: Upper extremity (UE) trauma represents a common reason for emergency department visits, but the longitudinal economic burden of this public health issue is unknown. This study assessed the 3-year attributable health care use and expenditure after UE trauma requiring acute surgical intervention, with specific focus on injuries that affect function of the hand and wrist. METHODS: We conducted an incidence-based, propensity score-matched cohort study (2006-2014) in Ontario, Canada, using linked administrative health care data to identify case patients and matched control patients. We matched adults with hand, wrist and UE nerve trauma requiring surgery 1:4 to control patients. We compared total direct health care costs, including 1-year pre-index costs, between case and control patients using a differences-in-difference methodology. The primary outcome was attributable health care costs within 3 years of injury. RESULTS: We matched patients with trauma (n = 26 123) to noninjured patients (n = 104 353). Mean direct health care costs attributable to UE trauma were $9210 (95% confidence interval [CI] 8880 to 9550) within 3 years. Patients with trauma had significantly more emergency department visits (≥ 3 visits: 25% v. 12%; p < 0.001), mental health visits (34% v. 28%; p < 0.05) and secondary surgeries (25% v. 5%; p < 0.001). Specific patient populations had significantly greater attributable costs: patients requiring post-traumatic mental health visits ($11 360 v. $7090; p < 0.001), inpatient surgery ($14 060 v. $5940, p < 0.001) and complex injuries ($13 790 v. $7930; p < 0.001). INTERPRETATION: Health care expenditure increased more than fivefold in the year after UE trauma surgery and remained greater than the matched cohort for the subsequent 2 years. Those with more serious injuries and post-injury visits for mental health were associated with higher costs, requiring further study for this public health issue. The mean 1-year pre-injury and 1-year post-injury total costs were $1710 and $9350, respectively.

The Burden of Surviving Childhood Medulloblastoma: A Population-Based, Matched Cohort Study in Ontario, Canada.

PURPOSE: Survivors of childhood medulloblastoma suffer from substantial late effects. We characterized these sequelae using real-world health services data in a population-based cohort of medulloblastoma survivors. METHODS: All 5-year medulloblastoma survivors diagnosed age < 18 years between 1987 and 2015 in Ontario, Canada, were identified and matched 1:5 with population controls. Index date was 5 years from latest pediatric cancer event. Linkage to provincial administrative health data allowed for comparison of cumulative incidences of several adverse outcomes. RESULTS: Two hundred thirty survivors, 81.3% of whom had received craniospinal irradiation, were matched with 1,150 controls. The 10-year postindex cumulative incidence of all-cause mortality was 7.9% (95% CI, 3.9 to 11.8) in survivors versus 0.6% (95% CI, 0.1 to 1.1) in controls (hazard ratio [HR], 21.5; 95% CI, 9.8 to 54.0). The cumulative incidence of stroke was higher in survivors (4.8%; 95% CI, 2.2 to 9.0) compared with controls (0.1; 95% CI, 0.01 to 0.7; HR, 45.6; 95% CI, 12.8 to 289.8). Hearing loss requiring an amplification device was present in 24.9% (95% CI, 18.8 to 31.4) of survivors versus 0.3% (95% CI, 0.1 to 1.0) of controls (HR, 96.3; 95% CI, 39.7 to 317.3). Disability support prescription claims were submitted by 44.5% (95% CI, 37.1 to 51.6) of survivors versus 5.5% (95% CI, 4.2 to 7.1) of controls (HR, 10.0; 95% CI, 7.3 to 13.6). Female survivors were significantly less likely to deliver a liveborn child compared with controls (HR, 0.2; 95% CI, 0.1 to 0.7). CONCLUSION: Survivors of medulloblastoma have significant long-term medical sequelae, increased all-cause mortality, and are frequently dependent on disability supports. Efforts to reduce the toxicity of current therapy, specifically incorporating molecularly informed risk stratification to spare low- and intermediate-risk survivors the toxicity of treatment, are urgently needed. These findings should prompt a re-evaluation of our current treatment approaches where research focused on late-effect interventions should be prioritized.

Prescription Pathways from Initial Medication Use to Triple Therapy in Older COPD Patients: A Real-World Population Study.

BACKGROUND AND OBJECTIVE: Triple therapy with an inhaled corticosteroid (ICS), a long-acting ß2-agonist bronchodilator (LABA) and a long-acting muscarinic antagonist (LAMA) is recommended as step-up therapy for chronic obstructive pulmonary disease (COPD) patients who continue to have persistent symptoms and increased risk of exacerbation despite treatment with dual therapy. We sought to evaluate different treatment pathways through which COPD patients were escalated to triple therapy. METHODS: We used population health databases from Ontario, Canada to identify individuals aged 66 or older with COPD who started triple therapy between 2014 and 2017. Median time from diagnosis to triple therapy was estimated using the Kaplan-Meier method. We classified treatment pathways based on treatments received prior to triple therapy and evaluated whether pathways differed by exacerbation history, blood eosinophil counts or time period. RESULTS: Among 4108 COPD patients initiating triple therapy, only 41.2% had a COPD exacerbation in the year prior. The three most common pathways were triple therapy as initial treatment (32.5%), LAMA to triple therapy (29.8%), and ICS + LABA to triple therapy (15.4%). Median time from diagnosis to triple therapy was 362 days (95% confidence interval:331-393 days) overall, but 14 days (95% CI 12-17 days) in the triple therapy as initial treatment pathway. This pathway was least likely to contain patients with frequent or severe exacerbations (22.0% vs. 31.5%, p < 0.001) or with blood eosinophil counts ≥300 cells/µL (18.9% vs. 22.0%, p < 0.001). CONCLUSION: Real-world prescription of triple therapy often does not follow COPD guidelines in terms of disease severity and prior treatments attempted.

Development of algorithms to identify individuals with Neurofibromatosis type 1 within administrative data and electronic medical records in Ontario, Canada.

BACKGROUND: There is limited population-based data on Neurofibromatosis type 1 (NF1) in North America. We aimed to develop and validate algorithms using administrative health data and electronic medical records (EMRs) to identify individuals with NF1 in Ontario, Canada. METHODS: We conducted an electronic free-text search of 15 commonly-used terms related to NF1 in the Electronic Medical Records Primary Care Database. Records were reviewed by two trained abstractors who classified them as confirmed, possible, and not NF1. An investigator with clinical expertise performed final NF1 classification. Patients were classified as confirmed if there was a documented diagnosis, meeting NIH criteria. Patients were classified as possible if (1) NF1 was recorded in the cumulative patient profile, but no clinical information to support the diagnosis; (2) only one criterion for diagnosis (e.g. child of confirmed case) but no further data to confirm or rule out. We tested different combinations of outpatient and inpatient billing codes, and applied a free-text search algorithm to identify NF1 cases in administrative data and EMRs, respectively. RESULTS: Of 273,440 eligible patients, 2,058 had one or more NF1 terms in their medical records. The terms "NF", "café-au-lait", or "sheath tumour" were constrained to appear in combination with another NF1 term. This resulted in 837 patients: 37 with possible and 71 with confirmed NF1. The population prevalence ranged from 1 in 3851 (confirmed NF1) to 1 in 2532 (possible and confirmed NF1). Billing code algorithms had poor performance, with overall low PPV (highest being 71%). The accuracy of the free-text EMR algorithm in identifying patients with NF1 was: sensitivity 85% (95% CI 74-92%), specificity 100% (95% CI 100-100%), positive predictive value 80% (95% CI 69-88%), negative predictive value 100% (95% CI 100-100%), and false positive rate 20% (95% CI 11-33%). Of false positives, 53% were possible NF1. CONCLUSIONS: A free-text search algorithm within the EMR had high sensitivity, specificity and predictive values. Algorithms using billing codes had poor performance, likely due to the lack of NF-specific codes for outpatient visits. While NF1 ICD-9 and 10 codes are used for hospital admissions, only ~ 30% of confirmed NF1 cases had a hospitalization associated with an NF1 code.

Trends in non-receipt of recommended COPD medication.

Receipt of sufficient COPD medication has improved over time; however, recommended therapy continues to be underused, especially in patients at lower risk of COPD exacerbation https://bit.ly/3IhK5Y4.

Evaluation of definitions for oral anticoagulant-associated major bleeding: A population-based cohort study.

INTRODUCTION: Major bleeding is the most serious complication of oral anticoagulants (OACs). While consensus criteria to define major bleeding have been established by the International Society for Thrombosis and Haemostasis (ISTH), Bleeding Academic Research Consortium (BARC) and Thrombolysis in Myocardial Infarction (TIMI), significant variability exists across these definitions. We sought to evaluate the agreement of cases identified by the three definitions and to assess their effect on mortality and OAC resumption. METHODS: We used a dataset of individuals ≥66 years in Ontario, Canada presenting with OAC-related bleeding from 2010 to 2015. For case agreement, we calculated Cohen's κ between the three major bleeding definitions. We used multivariate regression to determine differences in mortality and OAC resumption among ISTH, BARC and TIMI-defined major bleeds. RESULTS: Among 2002 cases of OAC-related bleeding, agreement in case identification between ISTH and BARC was substantial (Cohen's κ = 0.69); however, agreement between TIMI and other definitions were poor. Using 30-day mortality of clinically relevant non-major bleeds as comparator, ISTH-, BARC- and TIMI-defined major bleeds conferred 3.3-, 3.2- and 5.9-fold increased risk. Among survivors, 50% with ISTH- and BARC-defined major bleeds resumed OACs at 180 days, compared to 31% of TIMI-associated cases. CONCLUSION: Major bleeds identified by ISTH and BARC criteria showed good agreement and similar prognostic utility, whereas TIMI criteria identified patients at greater clinical risk. Our results highlight the need to revise major bleeding definitions based on criteria that are independently predictive of clinically relevant morbidity and mortality to more effectively reflect the risk associated with major bleeding and appropriately influence anticoagulant therapy decisions.

Potential Unintended Consequences of Antipsychotic Reduction in Ontario Nursing Homes.

OBJECTIVE: Antipsychotic reduction in nursing homes has been a focus of research and policy attention for several decades; however, there is evidence that these initiatives may have had unintended consequences, such as medication substitution and changes in diagnosis coding. Our objectives were to describe temporal changes in the use of antipsychotics, potential substitution medications, and diagnoses and symptoms used to establish the appropriateness of antipsychotic prescribing. DESIGN: Repeated cross-sectional study design. SETTING AND PARTICIPANTS: Individuals, 66 to 105 years of age, living in nursing homes in Ontario, Canada between April 1, 2010 and December 31, 2019. METHODS: Linked health administrative and clinical data were used to estimate the quarterly prevalence of dispensed antipsychotics, antidepressants, anticonvulsants, and benzodiazepines, as well as diagnoses and symptoms (eg, schizophrenia and delusions) applied to establish the appropriateness of antipsychotic use. Generalized linear models with generalized estimating equations, binomial distribution, and identity link function estimated the absolute changes over time among the population overall, by dementia diagnosis, and by severity of aggressive behaviors and cognitive impairment. RESULTS: Among over 70,000 nursing home residents each quarter, we observed general declines in antipsychotic (-0.70% per year [95% confidence limit (CL) -0.74%, -0.66%]) and benzodiazepine use (-1.17% per year [95% CL -1.20%, -1.14%]), and increases in antidepressant (0.89% per year [95% CL 0.84%, 0.94%]) and anticonvulsant use (1.06% per year [95% CL 1.03%, 1.09%]). Although initially stable, the coding of delusions increased from 3.5% to 10.2% (1.18% per year [95% CL 1.12%, 1.24%]) between 2014 and 2019, whereas schizophrenia remained stable. Increases in antidepressant use and recorded delusions were more pronounced among residents with dementia and aggressive behaviors. CONCLUSIONS AND IMPLICATIONS: Medication substitution and changes in diagnosis/symptom coding may be potential unintended consequences of initiatives to reduce inappropriate antipsychotic use. How this corresponds to resident-level prescribing and clinical outcomes warrants further investigation.

Quantifying cancer risk from exposures to medical imaging in the Risk of Pediatric and Adolescent Cancer Associated with Medical Imaging (RIC) Study: research methods and cohort profile.

PURPOSE: The Risk of Pediatric and Adolescent Cancer Associated with Medical Imaging (RIC) Study is quantifying the association between cumulative radiation exposure from fetal and/or childhood medical imaging and subsequent cancer risk. This manuscript describes the study cohorts and research methods. METHODS: The RIC Study is a longitudinal study of children in two retrospective cohorts from 6 U.S. healthcare systems and from Ontario, Canada over the period 1995-2017. The fetal-exposure cohort includes children whose mothers were enrolled in the healthcare system during their entire pregnancy and followed to age 20. The childhood-exposure cohort includes children born into the system and followed while continuously enrolled. Imaging utilization was determined using administrative data. Computed tomography (CT) parameters were collected to estimate individualized patient organ dosimetry. Organ dose libraries for average exposures were constructed for radiography, fluoroscopy, and angiography, while diagnostic radiopharmaceutical biokinetic models were applied to estimate organ doses received in nuclear medicine procedures. Cancers were ascertained from local and state/provincial cancer registry linkages. RESULTS: The fetal-exposure cohort includes 3,474,000 children among whom 6,606 cancers (2394 leukemias) were diagnosed over 37,659,582 person-years; 0.5% had in utero exposure to CT, 4.0% radiography, 0.5% fluoroscopy, 0.04% angiography, 0.2% nuclear medicine. The childhood-exposure cohort includes 3,724,632 children in whom 6,358 cancers (2,372 leukemias) were diagnosed over 36,190,027 person-years; 5.9% were exposed to CT, 61.1% radiography, 6.0% fluoroscopy, 0.4% angiography, 1.5% nuclear medicine. CONCLUSION: The RIC Study is poised to be the largest study addressing risk of childhood and adolescent cancer associated with ionizing radiation from medical imaging, estimated with individualized patient organ dosimetry.

Increased Mortality for Individuals With Giant Cell Arteritis: A Population-Based Study.

OBJECTIVE: Reports of mortality risks among individuals with giant cell arteritis (GCA) have been mixed. Our aim was to evaluate all-cause mortality among individuals with GCA relative to the general population over time. METHODS: We performed a population-based study in Ontario, Canada using health administrative data. We studied a cohort of 22,677 GCA patients ages ≥50 years that was identified using a validated case definition (with 81% positive predictive value, 100% specificity). General population comparators were residents ages ≥50 years without GCA. Deaths were ascertained from vital statistics. Annual crude, age- and sex-standardized, and age- and sex-specific all-cause mortality rates were determined for individuals with and without GCA between 2000 and 2018. Standardized mortality ratios (SMRs) were estimated. RESULTS: Age- and sex-standardized mortality rates were significantly higher for GCA patients than comparators, and trending to increase over time with 50.0 deaths per 1,000 GCA patients in 2000 (95% confidence interval [95% CI] 34.0-71.1) and 57.6 deaths per 1,000 GCA patients in 2018 (95% CI 50.8-65.2), whereas mortality rates in the general population significantly declined over time. The annual SMRs for GCA patients generally increased over time, with the lowest SMR occurring in 2002 (1.22 [95% CI 1.03-1.40]) and the highest in 2018 (1.92 [95% CI 1.81-2.03]). GCA mortality rates were more elevated for male patients than female patients. CONCLUSION: Over a 19-year period, mortality rates were increased among GCA patients relative to the general population, and more premature deaths were occurring in younger age groups. The relative excess mortality for GCA patients did not improve over time.

Risks of late mortality and morbidity among survivors of childhood acute leukemia with Down syndrome: A population-based cohort study.

BACKGROUND: Children with leukemia and Down syndrome (DS) are at higher risk of acute treatment toxicities than those without DS. Whether late toxicity risks are also elevated is unknown. METHODS: The authors identified all patients diagnosed with leukemia before the age of 18 years in Ontario, Canada between 1987 and 2013 and who survived greater than 5 years since their last pediatric cancer event. Survivors were divided into those with and without DS, matched by birth year, sex, leukemia type, and receipt of radiation. DS survivors were matched to individuals with DS without childhood cancer (DS controls) in a 1:10 ratio. Outcomes were identified through linkage to population-based health services databases. RESULTS: DS survivors (n = 79) experienced inferior overall survival compared to non-DS survivors (n = 231) (20-year overall survival, 81.7% ± 6.8% vs 98.3% ± 1.2%; hazard ratio [HR], 12.8; P < .0001) and to DS controls (n = 790; 96.3% ± 1.2%; HR, 5.4 P < .0001). Pulmonary and infectious deaths were noted among DS survivors. There was no difference in the incidence of congestive heart failure between DS survivors and either control cohort, nor of hearing loss or dementia between DS survivors and DS controls. CONCLUSIONS: DS survivors were at substantially higher risk of late mortality than non-DS survivors or DS controls. This excess risk was not attributable to cardiac- or subsequent malignant neoplasm-related late effects, historically main causes of premature death among non-DS survivors. Chronic morbidities associated with DS were not increased compared to DS controls. DS-specific surveillance guidelines may be warranted.

Incidence of Stroke in Immigrants to Canada: A Province-wide Retrospective Analysis.

OBJECTIVE: To evaluate the association between immigration status and stroke incidence. METHODS: We conducted a retrospective cohort study of 8 million adults (15% immigrants) residing in Ontario, Canada on January 1, 2003, with no history of prior stroke or transient ischemic attack (TIA). Subjects were followed until March 31, 2018 to identify incident stroke or TIA, defined as hospitalization or emergency room visit. We calculated adjusted hazard ratios (HR) of stroke or TIA in immigrants compared to long-term residents using cause-specific hazard models, adjusting for demographics and comorbidities. We evaluated whether the association varied by age, stroke type or country of origin of immigrants. RESULTS: During 109 million person-years follow-up, we observed 235,336 incident stroke or TIA events. Compared to long-term residents, immigrants had a lower rate of stroke or TIA (10.9 vs. 23.4 per 10,000 person-years, HR 0.67; 0.66-0.68). This was true across all age groups and stroke types, with a HR in immigrants vs. long-term residents for ischemic stroke of 0.71 (0.69-0.72), intracerebral hemorrhage 0.89 (0.85-0.93), subarachnoid hemorrhage 0.85 (0.81-0.91), and TIA 0.53 (0.51-0.54). The magnitude of the reduction in stroke risk associated with immigration status was less pronounced in immigrants from the Caribbean (HR 0.95; 0.91-1.00), Latin America (HR 0.85;0.82-0.91) and Africa (HR 0.80; 0.74-0.85) than in those from other world regions. CONCLUSIONS: Immigrants have a lower rate of stroke or TIA than long-term residents with variation by age, stroke type and country of origin. This knowledge may be useful for developing targeted primary stroke prevention strategies.

High prevalence of comorbidities at diagnosis in immigrants with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) has been associated with certain comorbidities in general population studies, but it is unknown how comorbidity may affect immigrants with MS. OBJECTIVE: To compare prevalence of comorbidities in immigrants and long-term residents at MS diagnosis, and in matched control populations without MS. METHODS: We identified incident MS cases using a validated definition applied to health administrative data in Ontario, Canada, from 1994 to 2017, and categorized them as immigrants or long-term residents. Immigrants and long-term residents without MS (controls) were matched to MS cases 3:1 on sex, age, and geography. RESULTS: There were 1534 immigrants and 23,731 long-term residents with MS matched with 4585 and 71,193 controls, respectively. Chronic obstructive pulmonary disease (COPD), diabetes, hypertension, ischemic heart disease, migraine, epilepsy, mood/anxiety disorders, schizophrenia, inflammatory bowel disease (IBD), and rheumatoid arthritis were significantly more prevalent among immigrants with MS compared to their controls. Prevalence of these conditions was generally similar comparing immigrants to long-term residents with MS, although COPD, epilepsy, IBD, and mood/anxiety disorders were less prevalent in immigrants. CONCLUSION: Immigrants have a high prevalence of multiple comorbidities at MS diagnosis despite the "healthy immigrant effect." Clinicians should pay close attention to identification and management of comorbidity in immigrants with MS.

Factors Associated With Nonreceipt of Recommended COPD Medications: A Population Study.

BACKGROUND: COPD medications reduce exacerbations and improve quality of life. Despite this, some individuals do not receive medications recommended by practice guidelines. RESEARCH QUESTION: How common is nonreceipt of recommended medications among people with COPD, and what factors are associated with nonreceipt? STUDY DESIGN AND METHODS: This population cohort study was conducted in Ontario, Canada, a province with universal health care insurance and medication coverage for those aged ≥ 65 years. Health administrative data were used to identify people aged ≥ 66 years with physician-diagnosed COPD as of 2018 and group them into cohorts of lower or higher risk for future COPD exacerbations. Proportions of patients in each group who did not receive medications recommended by COPD guidelines were determined. Generalized estimating equation modeling was used to determine associations between patient and physician factors and nonreceipt of recommended medications. RESULTS: About 54% and 88% of people with COPD received sufficient recommended medications in the low and high risk of exacerbation groups, respectively. Longer duration of COPD, higher comorbidity, dementia, and older physician age were associated with nonreceipt of recommended medications in both groups. People who had a co-diagnosis of asthma, who received care by a pulmonologist and who received spirometry were more likely to receive recommended medication. INTERPRETATION: COPD medications seem underused by the COPD population, and various factors are associated with suboptimal receipt. Targeting these factors would help improve the care and health of people with COPD.

Stroke Incidence by Sex Across the Lifespan.

BACKGROUND AND PURPOSE: We evaluated the influence of age on the association between sex and the incidence of stroke or transient ischemic attack (TIA) using a population-based cohort from Ontario, Canada. METHODS: We followed a cohort of adults (≥18 years) without prior stroke from January 1, 2003 (cohort start date) to March 31, 2018, to identify incident events. We calculated hazard ratios (HRs), in women compared to men, of incident stroke or TIA, adjusted for demographics and comorbidities, overall and stratified by stroke type. We calculated piecewise adjusted HRs for each decade of age to evaluate the effect of age on sex differences in stroke incidence. RESULTS: We followed 9.2 million adults for a median of 15 years and observed 280,197 incident stroke or TIA events. Compared with men, women had an overall lower adjusted hazard of stroke or TIA (HR, 0.82 [95% CI, 0.82-0.83]), with similar findings across all stroke types except for subarachnoid hemorrhage (HR, 1.29 [95% CI, 1.24-1.33]). We found a U-shaped association between age and sex differences in the incidence of stroke or TIA: compared with men, the hazard of stroke was higher in women among those aged ≤30 years (HR, 1.26 [95% CI, 1.10-1.45]), lower among those between ages 40 and 80 years (eg, age 50-59, HR, 0.69 [95% CI, 0.68-0.70]), and similar among those aged ≥80 years (HR, 0.99 [95% CI, 0.98-1.01]). CONCLUSIONS: Overall, women have a lower hazard of stroke than men, but this association varies by age and across stroke types. Recognition of age-sex variations in stroke incidence can help guide prevention efforts to reduce stroke incidence in both men and women.

Morbidity and mortality associated with prescription cannabinoid drug use in COPD.

INTRODUCTION: Respiratory-related morbidity and mortality were evaluated in relation to incident prescription oral synthetic cannabinoid (nabilone, dronabinol) use among older adults with chronic obstructive pulmonary disease (COPD). METHODS: This was a retrospective, population-based, data-linkage cohort study, analysing health administrative data from Ontario, Canada, from 2006 to 2016. We identified individuals aged 66 years and older with COPD, using a highly specific, validated algorithm, excluding individuals with malignancy and those receiving palliative care (n=185 876 after exclusions). An equivalent number (2106 in each group) of new cannabinoid users (defined as individuals dispensed either nabilone or dronabinol, with no dispensing for either drug in the year previous) and controls (defined as new users of a non-cannabinoid drug) were matched on 36 relevant covariates, using propensity scoring methods. Cox proportional hazard regression was used. RESULTS: Rate of hospitalisation for COPD or pneumonia was not significantly different between new cannabinoid users and controls (HR 0.87; 95% CI 0.61-1.24). However, significantly higher rates of all-cause mortality occurred among new cannabinoid users compared with controls (HR 1.64; 95% CI 1.14-2.39). Individuals receiving higher-dose cannabinoids relative to controls were observed to experience both increased rates of hospitalisation for COPD and pneumonia (HR 2.78; 95% CI 1.17-7.09) and all-cause mortality (HR 3.31; 95% CI 1.30-9.51). CONCLUSIONS: New cannabinoid use was associated with elevated rates of adverse outcomes among older adults with COPD. Although further research is needed to confirm these observations, our findings should be considered in decisions to use cannabinoids among older adults with COPD.