Characteristics of primary care practices by proportion of patients unvaccinated against SARS-CoV-2: a cross-sectional cohort study.

BACKGROUND: Variations in primary care practices may explain some differences in health outcomes during the COVID-19 pandemic. We sought to evaluate the characteristics of primary care practices by the proportion of patients unvaccinated against SARS-CoV-2. METHODS: We conducted a population-based, cross-sectional cohort study using linked administrative data sets in Ontario, Canada. We calculated the percentage of patients unvaccinated against SARS-CoV-2 enrolled with each comprehensive-care family physician, ranked physicians according to the proportion of patients unvaccinated, and identified physicians in the top 10% (v. the other 90%). We compared characteristics of family physicians and their patients in these 2 groups using standardized differences. RESULTS: We analyzed 9060 family physicians with 10 837 909 enrolled patients. Family physicians with the largest proportion (top 10%) of unvaccinated patients (n = 906) were more likely to be male, to have trained outside of Canada, to be older, and to work in an enhanced fee-for-service model than those in the remaining 90%. Vaccine coverage (≥ 2 doses of SARS-CoV-2 vaccine) was 74% among patients of physicians with the largest proportion of unvaccinated patients, compared with 87% in the remaining patient population. Patients in the top 10% group tended to be younger and live in areas with higher levels of ethnic diversity and immigration and lower incomes. INTERPRETATION: Primary care practices with the largest proportion of patients unvaccinated against SARS-CoV-2 served marginalized communities and were less likely to use team-based care models. These findings can guide resource planning and help tailor interventions to integrate public health priorities within primary care practices.

Characteristics of patients attached to near-retirement family physicians: a population-based serial cross-sectional study in Ontario, Canada.

OBJECTIVES: Population ageing is a global phenomenon. Resultant healthcare workforce shortages are anticipated. To ensure access to comprehensive primary care, which correlates with improved health outcomes, equity and costs, data to inform workforce planning are urgently needed. We examined the medical and social characteristics of patients attached to near-retirement comprehensive primary care physicians over time and explored the early-career and mid-career workforce's capacity to absorb these patients. DESIGN: A serial cross-sectional population-based analysis using health administrative data. SETTING: Ontario, Canada, where most comprehensive primary care is delivered by family physicians (FPs) under universal insurance. PARTICIPANTS: All insured Ontario residents at three time points: 2008 (12 936 360), 2013 (13 447 365) and 2019 (14 388 566) and all Ontario physicians who billed primary care services (2008: 11 566; 2013: 12 693; 2019: 15 054). OUTCOME MEASURES: The number, proportion and health and social characteristics of patients attached to near-retirement age comprehensive FPs over time; the number, proportion and characteristics of near-retirement age comprehensive FPs over time. SECONDARY OUTCOME MEASURES: The characteristics of patients and their early-career and mid-career comprehensive FPs. RESULTS: Patient attachment to comprehensive FPs increased over time. The overall FP workforce grew, but the proportion practicing comprehensiveness declined (2008: 77.2%, 2019: 70.7%). Over time, an increasing proportion of the comprehensive FP workforce was near retirement age. Correspondingly, an increasing proportion of patients were attached to near-retirement physicians. By 2019, 13.9% of comprehensive FPs were 65 years or older, corresponding to 1 695 126 (14.8%) patients. Mean patient age increased, and all physicians served markedly increasing numbers of medically and socially complex patients. CONCLUSIONS: The primary care sector faces capacity challenges as both patients and physicians age and fewer physicians practice comprehensiveness. Nearly 15% (1.7 million) of Ontarians may lose their comprehensive FP to retirement between 2019 and 2025. To serve a growing, increasingly complex population, innovative solutions are needed.

Cancer Screening Disparities Before and After the COVID-19 Pandemic.

Importance: Breast, cervical, and colorectal cancer-screening disparities existed prior to the COVID-19 pandemic, and it is unclear whether those have changed since the pandemic. Objective: To assess whether changes in screening from before the pandemic to after the pandemic varied for immigrants and for people with limited income. Design, Setting, and Participants: This population-based, cross-sectional study, using data from March 31, 2019, and March 31, 2022, included adults in Ontario, Canada, the country's most populous province, with more than 14 million people, almost 30% of whom are immigrants. At both dates, the screening-eligible population for each cancer type was assessed. Exposures: Neighborhood income quintile, immigrant status, and primary care model type. Main Outcomes and Measures: For each cancer screening type, the main outcome was whether the screening-eligible population was up to date on screening (a binary outcome) on March 31, 2019, and March 31, 2022. Up to date on screening was defined as having had a mammogram in the previous 2 years, a Papanicolaou test in the previous 3 years, and a fecal test in the previous 2 years or a flexible sigmoidoscopy or colonoscopy in the previous 10 years. Results: The overall cohort on March 31, 2019, included 1 666 943 women (100%) eligible for breast screening (mean [SD] age, 59.9 [5.1] years), 3 918 225 women (100%) eligible for cervical screening (mean [SD] age, 45.5 [13.2] years), and 3 886 345 people eligible for colorectal screening (51.4% female; mean [SD] age, 61.8 [6.4] years). The proportion of people up to date on screening in Ontario decreased for breast, cervical, and colorectal cancers, with the largest decrease for breast screening (from 61.1% before the pandemic to 51.7% [difference, -9.4 percentage points]) and the smallest decrease for colorectal screening (from 65.9% to 62.0% [difference, -3.9 percentage points]). Preexisting disparities in screening for people living in low-income neighborhoods and for immigrants widened for breast screening and colorectal screening. For breast screening, compared with income quintile 5 (highest), the ß estimate for income quintile 1 (lowest) was -1.16 (95% CI, -1.56 to -0.77); for immigrant vs nonimmigrant, the ß estimate was -1.51 (95% CI, -1.84 to -1.18). For colorectal screening, compared with income quintile 5, the ß estimate for quntile 1 was -1.29 (95% CI, 16 -1.53 to -1.06); for immigrant vs nonimmigrant, the ß estimate was -1.41 (95% CI, -1.61 to -1.21). The lowest screening rates both before and after the COVID-19 pandemic were for people who had no identifiable family physician (eg, moving from 11.3% in 2019 to 9.6% in 2022 up to date for breast cancer). In addition, patients of interprofessional, team-based primary care models had significantly smaller reductions in ß estimates for breast (2.14 [95% CI, 1.79 to 2.49]), cervical (1.72 [95% CI, 1.46 to 1.98]), and colorectal (2.15 [95% CI, 1.95 to 2.36]) postpandemic screening and higher uptake of screening in general compared with patients of other primary care models. Conclusions and Relevance: In this cross-sectional study in Ontario that included 2 time points, widening disparities before compared with after the COVID-19 pandemic were found for breast cancer and colorectal cancer screening based on income and immigrant status, but smaller declines in disparities were found among patients of interprofessional, team-based primary care models than among their counterparts. Policy makers should investigate the value of prioritizing and investing in improving access to team-based primary care for people who are immigrants and/or with limited income.

Trends in attachment to a primary care provider in Ontario, 2008-2018: an interrupted time-series analysis.

BACKGROUND: Attachment to a regular primary care provider is associated with better health outcomes, but 15% of people in Canada lack a consistent source of ongoing primary care. We sought to evaluate trends in attachment to a primary care provider in Ontario in 2008-2018, through an equity lens and in relation to policy changes in implementation of payment reforms and team-based care. METHODS: Using linked, population-level administrative data, we conducted a retrospective observational study to calculate rates of patients attached to a regular primary care provider from Apr. 1, 2008, to Mar. 31, 2019. We evaluated the association of patient characteristics and attachment in 2018 using sex-stratified, adjusted, multivariable logistic regression models and used segmented piecewise regression to evaluate changing trends before and after implementation of a policy that restricted physician entry to alternate models. RESULTS: Attachment increased from 80.5% (n = 10 352 385) in 2008 to 88.9% of the population (n = 12 537 172) in 2018, but was lower among people with low comorbidity, high residential instability, material deprivation, rural residence and recent immigrants. Inequities narrowed for recent immigrants, males and people with lower incomes over the study period, but disparities persisted for these groups. Attachment grew by 1.47% annually until 2014 (p < 0.0001), but was stagnant thereafter (annual percent change of 0.13, p = 0.16). INTERPRETATION: Lack of sustained progress in attachment followed reduced levels of physician entry to alternate funding models. Although disparities narrowed for many groups over the study period, persistent gaps remained for immigrants and people with lower incomes; targeted interventions and policy changes are needed to address these persistent gaps.

Virtual Care and Emergency Department Use During the COVID-19 Pandemic Among Patients of Family Physicians in Ontario, Canada.

Importance: The COVID-19 pandemic has played a role in increased use of virtual care in primary care. However, few studies have examined the association between virtual primary care visits and other health care use. Objective: To evaluate the association between the percentage of virtual visits in primary care and the rate of emergency department (ED) visits. Design, Setting, and Participants: This cross-sectional study used routinely collected administrative data and was conducted in Ontario, Canada. The sample comprised family physicians with at least 1 primary care visit claim between February 1 and October 31, 2021, and permanent Ontario residents who were alive as of March 31, 2021. All residents were assigned to physicians according to enrollment and billing data. Exposure: Family physicians' virtual visit rate was the exposure. Physicians were stratified by the percentage of total visits that they delivered virtually (via telephone or video) during the study period (0% [100% in person], >0%-20%, >20%-40%, >40%-60%, >60%-80%, >80% to <100%, or 100%). Main Outcomes and Measures: Population-level ED visit rate was calculated for each stratum of virtual care use. Multivariable regression models were used to understand the relative rate of patient ED use after adjusting for rurality of practice, patient characteristics, and 2019 ED visit rates. Results: Data were analyzed for a total of 13 820 family physicians (7114 males [51.5%]; mean [SD] age, 50 [13.1] years) with 12 951 063 patients (6 714 150 females [51.8%]; mean [SD] age, 42.6 [22.9] years) who were attached to these physicians. Most physicians provided between 40% and 80% of care virtually. A higher percentage of the physicians who provided more than 80% of care virtually were 65 years or older, female individuals, and practiced in big cities. Patient comorbidity and morbidity were similar across strata of virtual care use. The mean (SD) number of ED visits was highest among patients whose physicians provided only in-person care (470.3 [1918.8] per 1000 patients) and was lowest among patients of physicians who provided more than 80% to less than 100% of care virtually (242.0 [800.3] per 1000 patients). After adjustment for patient characteristics, patients of physicians with more than 20% of visits delivered virtually had lower rates of ED visits compared with patients of physicians who provided more than 0% to 20% of care virtually (eg, >80% to <100% vs >0%-20% virtual visits in big cities: relative rate, 0.77%; 95% CI, 0.74%-0.81%). This pattern was unchanged across all rurality of practice strata and after adjustment for 2019 ED visit rates. In urban areas, there was a gradient whereby patients of physicians providing the highest level of virtual care had the lowest ED visit rates. Conclusions and Relevance: Findings of this study show that patients of physicians who provided a higher percentage of virtual care did not have higher ED visit rates compared with patients of physicians who provided the lowest levels of virtual care. The findings refute the hypothesis that family physicians providing more care virtually during the pandemic resulted in higher ED use.

Relational Continuity, Physician Payment, and Team-Based Primary Care in the Canadian Health Care System.

PURPOSE: Continuity is a core component of primary care and known to differ by patient characteristics. It is unclear how primary care physician payment and organization are associated with continuity. METHODS: We analyzed administrative data from 7,110,036 individuals aged 16+ in Ontario, Canada who were enrolled to a physician and made at least 2 visits between October 1, 2017 and September 30, 2019. Continuity with physician and practice group was quantified using the usual provider of care index. We used log-binomial regression to assess the relationship between enrollment model and continuity adjusting for patient characteristics. RESULTS: Mean physician and group continuity were 67.3% and 73.8%, respectively, for patients enrolled in enhanced fee-for-service, 70.7% and 76.2% for nonteam capitation, and 70.6% and 78.7% for team-based capitation. These differences were attenuated in regression models for physician-level continuity and group-level continuity. Older age was the most notable factor associated with continuity. Compared with those 16 to 34, those 80 and older had 1.45 times higher continuity with their physician. CONCLUSION: Our results suggest that continuity does not differ substantially by physician payment or organizational model among primary care patients who are formally enrolled with a physician in a setting with universal health insurance.

Family Physicians Stopping Practice During the COVID-19 Pandemic in Ontario, Canada.

We conducted 2 analyses using administrative data to understand whether more family physicians in Ontario, Canada stopped working during the COVID-19 pandemic compared with previous years. First, we found 3.1% of physicians working in 2019 (n = 385/12,247) reported no billings in the first 6 months of the pandemic; compared with other family physicians, a higher portion were aged 75 years or older (13.0% vs 3.4%, P <0.001), had fee-for-service reimbursement (37.7% vs 24.9%, P <0.001), and had a panel size under 500 patients (40.0% vs 25.8%, P <0.001). Second, a fitted regression line found the absolute increase in the percentage of family physicians stopping work was 0.03% per year from 2010 to 2019 (P = 0.042) but 1.2% between 2019 to 2020 (P <0.001). More research is needed to understand the impact of physicians stopping work on primary care attachment and access to care.

Primary care bonus payments and patient-reported access in urban Ontario: a cross-sectional study.

BACKGROUND: Rurality strongly correlates with higher pay-for-performance access bonuses, despite higher emergency department use and fewer primary care services than in urban settings. We sought to evaluate the relation between patient-reported access to primary care and access bonus payments in urban settings. METHODS: We conducted a cross-sectional, secondary data analysis using Ontario survey and health administrative data from 2013 to 2017. We used administrative data to calculate annual access bonuses for eligible urban family physicians. We linked this payment data to adult (≥ 16 yr) patient data from the Health Care Experiences Survey to examine the relation between access bonus achievement (in quintiles of the proportion of bonus achieved, from lowest [Q1, reference category] to highest [Q5]) and 4 patient-reported access outcomes. The average survey response rate to the patient survey during the study period was 51%. We stratified urban geography into large, medium and small settings. In a multilevel regression model, we adjusted for patient-, physician- and practice-level covariates. We tested linear trends, adjusted for clustering, for each outcome. RESULTS: We linked 18 893 respondents to 3940 physicians in 414 bonus-eligible practices. Physicians in small urban settings earned the highest proportion of their maximum potential access bonuses. Access bonus achievement was positively associated with telephone access (Q2 odds ratio [OR] 1.18, 95% confidence interval [CI] 0.98-1.42; Q3 OR 1.34, 95% CI 1.10-1.63; Q4 OR 1.46, 95% CI 1.19-1.79; Q5 OR 1.87, 95% CI 1.50-2.33), after hours access (Q2 OR 1.26, 95% CI 1.09-1.47; Q3 OR 1.46, 95% CI 1.23-1.74; Q4 OR 1.77, 95% CI 1.46-2.15; Q5 OR 1.88, 95% CI 1.52-2.32), wait time for care (Q2 OR 1.01, 95% CI 0.85-1.20; Q3 OR 1.17, 95% CI 0.97-1.41; Q4 OR 1.27, 95% CI 1.05-1.55; Q5 OR 1.63, 95% CI 1.32-2.00) and timeliness (Q2 OR 1.29, 95% CI 0.98-1.69; Q3 OR 1.29, 95% CI 0.94-1.77; Q4 OR 1.58, 95% CI 1.16-2.13; Q5 OR 1.98, 95% CI 1.38-2.82). When stratified by geography, we observed several of these associations in large urban settings, but not in small urban settings. Trend tests were statistically significant for all 4 outcomes. INTERPRETATION: Although the access bonus correlated with access in larger urban settings, it did not in smaller settings, aligning with previous research questioning its utility in smaller geographies. The access bonus may benefit from a redesign that considers geography and patient experience.

Problems in Coordinating and Accessing Primary Care for Attached and Unattached Patients Exacerbated During the COVID-19 Pandemic Year (the PUPPY Study): Protocol for a Longitudinal Mixed Methods Study.

BACKGROUND: The COVID-19 pandemic has significantly disrupted primary care in Canada, with many walk-in clinics and family practices initially closing or being perceived as inaccessible; pharmacies remaining open with restrictions on patient interactions; rapid uptake of virtual care; and reduced referrals for lab tests, diagnostics, and specialist care. OBJECTIVE: The PUPPY Study (Problems in Coordinating and Accessing Primary Care for Attached and Unattached Patients Exacerbated During the COVID-19 Pandemic Year) seeks to understand the impact of the COVID-19 pandemic across the quadruple aims of primary care, with particular focus on the effects on patients without attachment to a regular provider and those with chronic health conditions. METHODS: The PUPPY study builds on an existing research program exploring patients' access and attachment to a primary care practice, pivoted to adapt to the emerging COVID-19 context. We intend to undertake a longitudinal mixed methods study to understand critical gaps in primary care access and coordination, as well as compare prepandemic and postpandemic data across 3 Canadian provinces (Quebec, Ontario, and Nova Scotia). Multiple data sources will be used such as a policy review; qualitative interviews with primary care policymakers, providers (ie, family physicians, nurse practitioners, and pharmacists), and patients (N=120); and medication prescriptions and health care billing data. RESULTS: This study has received funding by the Canadian Institutes of Health Research COVID-19 Rapid Funding Opportunity Grant. Ethical approval to conduct this study was granted in Ontario (Queens Health Sciences & Affiliated Teaching Hospitals Research Ethics Board, file 6028052; Western University Health Sciences Research Ethics Board, project 116591; University of Toronto Health Sciences Research Ethics Board, protocol 40335) in November 2020, Québec (Centre intégré universitaire de santé et de services sociaux de l'Estrie, project 2020-3446) in December 2020, and Nova Scotia (Nova Scotia Health Research Ethics Board, file 1024979) in August 2020. CONCLUSIONS: To our knowledge, this is the first study of its kind to explore the effects of the COVID-19 pandemic on primary care systems, with particular focus on the issues of patient's attachment and access to primary care. Through a multistakeholder, cross-jurisdictional approach, the findings of the PUPPY study will inform the strengthening of primary care during and beyond the COVID-19 pandemic, as well as have implications for future policy and practice. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/29984.

Development and validation of an algorithm using health administrative data to define patient attachment to primary care providers.

PURPOSE: The authors developed and validated an algorithm using health administrative data to identify patients who are attached or uncertainly attached to a primary care provider (PCP) using patient responses to a survey conducted in Ontario, Canada. DESIGN/METHODOLOGY/APPROACH: The authors conducted a validation study using as a reference standard respondents to a community-based survey who indicated they did or did not have a PCP. The authors developed and tested health administrative algorithms against this reference standard. The authors calculated the sensitivity, specificity positive predictive value (PPV) and negative predictive value (NPV) on the final patient attachment algorithm. The authors then applied the attachment algorithm to the 2017 Ontario population. FINDINGS: The patient attachment algorithm had an excellent sensitivity (90.5%) and PPV (96.8%), though modest specificity (46.1%) and a low NPV (21.3%). This means that the algorithm assigned survey respondents as being attached to a PCP and when in fact they said they had a PCP, yet a significant proportion of those found to be uncertainly attached had indicated they did have a PCP. In 2017, most people in Ontario, Canada (85.4%) were attached to a PCP but 14.6% were uncertainly attached. RESEARCH LIMITATIONS/IMPLICATIONS: Administrative data for nurse practitioner's encounters and other interprofessional care providers are not currently available. The authors also cannot separately identify primary care visits conducted in walk in clinics using our health administrative data. Finally, the definition of hospital-based healthcare use did not include outpatient specialty care. PRACTICAL IMPLICATIONS: Uncertain attachment to a primary health care provider is a recurrent problem that results in inequitable access in health services delivery. Providing annual reports on uncertainly attached patients can help evaluate primary care system changes developed to improve access. This algorithm can be used by health care planners and policy makers to examine the geographic variability and time trends of the uncertainly attached population to inform the development of programs to improve primary care access. SOCIAL IMPLICATIONS: As primary care is an essential component of a person's medical home, identifying regions or high need populations that have higher levels of uncertainly attached patients will help target programs to support their primary care access and needs. Furthermore, this approach will be useful in future research to determine the health impacts of uncertain attachment to primary care, especially in view of a growing body of the literature highlighting the importance of primary care continuity. ORIGINALITY/VALUE: This patient attachment algorithm is the first to use existing health administrative data validated with responses from a patient survey. Using patient surveys alone to assess attachment levels is expensive and time consuming to complete. They can also be subject to poor response rates and recall bias. Utilizing existing health administrative data provides more accurate, timely estimates of patient attachment for everyone in the population.

Shifts in office and virtual primary care during the early COVID-19 pandemic in Ontario, Canada.

BACKGROUND: Globally, primary care changed dramatically as a result of the coronavirus disease 2019 (COVID-19) pandemic. We aimed to understand the degree to which office and virtual primary care changed, and for which patients and physicians, during the initial months of the pandemic in Ontario, Canada. METHODS: This population-based study compared comprehensive, linked primary care physician billing data from Jan. 1 to July 28, 2020, with the same period in 2019. We identified Ontario residents with at least 1 office or virtual (telephone or video) visit during the study period. We compared trends in total physician visits, office visits and virtual visits before COVID-19 with trends after pandemic-related public health measures changed the delivery of care, according to various patient and physician characteristics. We used interrupted time series analysis to compare trends in the early and later halves of the COVID-19 period. RESULTS: Compared with 2019, total primary care visits between March and July 2020 decreased by 28.0%, from 7.66 to 5.51 per 1000 people/day. The smallest declines were among patients with the highest expected health care use (8.3%), those who could not be attributed to a primary care physician (10.2%), and older adults (19.1%). In contrast, total visits in rural areas increased by 6.4%. Office visits declined by 79.1% and virtual care increased 56-fold, comprising 71.1% of primary care physician visits. The lowest uptake of virtual care was among children (57.6%), rural residents (60.6%) and physicians with panels of ≥ 2500 patients (66.0%). INTERPRETATION: Primary care in Ontario saw large shifts from office to virtual care over the first 4 months of the COVID-19 pandemic. Total visits declined least among those with higher health care needs. The determinants and consequences of these major shifts in care require further study.

Use of the health care system by Ontario First Nations people with diabetes: a population-based study.

BACKGROUND: First Nations people in Ontario have an increased prevalence of diabetes compared to other people in the province. This study examined use of health care services by First Nations people with diabetes and other people with diabetes in Ontario. METHODS: Using linked health administrative databases, we identified all people in Ontario with diabetes as of Apr. 1, 2014. We identified First Nations people using the Indian Register. We looked at outcomes from Apr. 1, 2014, to Mar. 31, 2015. We determined the proportion of people with a regular family physician and their continuity of care with that physician. We also examined visits with specialists for diabetes care, hospital admissions for ambulatory-care-sensitive conditions, and emergency department visits for hypo- or hyperglycemia. RESULTS: There were 1 380 529 people diagnosed with diabetes in Ontario as of Apr. 1, 2014, of whom 22 952 (1.7%) were First Nations people. First Nations people were less likely to have a regular family physician (85.3% v. 97.7%) and had lower continuity of care with that physician (mean score for continuity of care 74.6 v. 77.7) than other people in Ontario. They were also less likely to see specialists. First Nations people were more likely to be admitted to hospital for ambulatory-care-sensitive conditions (2.4% v. 1.2%) and to have an emergency department visit for hypo- or hyperglycemia (1.5% v. 0.8%). Disparities were particularly marked for those living in First Nations communities. INTERPRETATION: First Nations people with diabetes in Ontario had poorer access to and use of primary care than other people with diabetes in the province. These findings may help explain continued disparities in the rates of complications related to diabetes.

Diabetes-induced eye disease among First Nations people in Ontario: a longitudinal, population-based cohort study.

BACKGROUND: In Canada, First Nations populations experience a higher incidence of diabetes and diabetes-related complications than other people. Given the paucity of information on use of preventive eye examinations and the need for interventional care for severe retinopathy among First Nations people, we carried out a population-based study to compare rates of eye examinations and interventional therapies to treat vision-threatening stages of diabetic retinopathy among First Nations people and other people with diabetes in Ontario. METHODS: In collaboration with the Chiefs of Ontario, we carried out a population-based study to identify cohorts of First Nations people and other people with diabetes in Ontario from 1995/96 to 2014/15. We used linked health administrative databases to evaluate rates of eye examination (2005/06-2014/15) and severe diabetic retinopathy treatment and compared them between the 2 populations, and between First Nations people living in and outside of First Nations communities. RESULTS: We identified 23 013 First Nations people and 1 364 222 other people diagnosed with diabetes from 1995/96 to 2014/15, of whom 49.8% (95% confidence interval [CI] 48.9%-50.7%) and 53.8% (95% CI 53.7%-54.0%), respectively, received an eye examination in 2014/15. Eye examination rates were similar for First Nations people regardless of whether they lived in or outside a First Nations community. First Nations people developed severe diabetic retinopathy at a faster rate than other people (hazard ratio 1.19, 95% CI 1.02-1.38). The gap between First Nations people and other people in the proportion requiring therapy for severe diabetic retinopathy was especially prominent among younger people. There were no significant differences in rates of diabetic retinopathy treatment in First Nations people stratified by place of residence. INTERPRETATION: Eye examination rates remain suboptimal among people with diabetes in Ontario and were lower among First Nations people. This is particularly concerning in light of our other findings showing an increased risk of requiring treatment for advanced diabetic retinopathy and the accelerated rate of diabetic retinopathy progression among First Nations people with diabetes.

Hospital admission for stroke or transient ischemic attack among First Nations people with diabetes in Ontario: a population-based cohort study.

BACKGROUND: First Nations people have high rates of diabetes mellitus, which is a risk factor for stroke. We studied the rates of hospital admission, processes of care and outcomes of stroke and transient ischemic attack (TIA) in First Nations people in Ontario. METHODS: Using linked administrative databases, we identified annual cohorts of people aged 20-105 years in Ontario with prevalent diabetes between Apr. 1, 1995, and Mar. 31, 2015. We identified Status First Nations people in Ontario from the Indian Register. We compared age- and sex-standardized rates of hospital admission for stroke or TIA, processes of care and case fatality among First Nations versus other people in Ontario with diabetes. RESULTS: Overall, 28 874 people with diabetes (of whom 536 were First Nations people) were admitted to hospital with a stroke or TIA between Apr. 1, 2011, and Mar. 31, 2016. Admission rates for stroke or TIA declined over the study period but were higher among First Nations people than other Ontarians in most years after 2005/06. First Nations people admitted with stroke or TIA were as likely as other Ontarians to undergo neuroimaging within 24 hours (94.6% v. 96.0%), be discharged to inpatient rehabilitation (31.8% v. 34.8%) and receive carotid revascularization (1.4% v. 2.7%), but were less likely to receive thrombolysis (6.3% v. 11.0%). Age- and sex-standardized stroke case fatality was similar in First Nations people and other Ontarians at 7 days (12.0% v. 8.5%), 30 days (19.2% v. 16.0%) and 1 year (33.8% v. 28.1%). INTERPRETATION: Rates of hospital admission for stroke or TIA were higher among First Nations people than other people with diabetes in Ontario. Future work should focus on determining Indigenous-specific determinants of health related to this disparity and implementing appropriate interventions to mitigate the risks and sequelae of stroke in First Nations people.

Characterizing risk of type 2 diabetes in First Nations people living in First Nations communities in Ontario: a population-based analysis using cross-sectional survey data.

BACKGROUND: Population-based planning tools are important for informing diabetes-prevention efforts in First Nations communities. We used the Diabetes Population Risk Tool (DPoRT) to predict 10-year diabetes risk and describe the factors that contribute to diabetes risk in First Nations adults living in Ontario First Nations communities. METHODS: We examined population data from adult (≥ 20 yr) respondents to the First Nations Regional Health Survey (RHS) phase 3, a representative cohort of First Nations people living in Ontario First Nations communities. We applied the DPoRT to risk factor information in the survey to predict the distribution of 10-year type 2 diabetes incidence and number of new diabetes cases from 2015/16 to 2025/26. RESULTS: There were 993 respondents to the RHS phase 3 adult survey, of whom 936 (708 without diabetes and 228 with a diagnosis of type 2 diabetes) were eligible for inclusion. The DPoRT predicted a type 2 diabetes risk of 9.6% (confidence interval [CI] 8.3-10.8) between 2015/16 and 2025/26, corresponding to 3501 (95% CI 2653-4348) new diabetes cases. Diabetes cases were predicted to occur disproportionately among those experiencing food insecurity, low income, overweight, obesity and physical inactivity. Reduced diabetes risk was predicted among those who reported connections to Indigenous culture, as measured by eating traditional vegetative foods a few times or often in the previous 12 months. INTERPRETATION: Socioeconomic conditions and known risk factors for type 2 diabetes are important determinants of diabetes risk in First Nations communities. Culturally appropriate policies, programming and services that address socioeconomic disadvantage and other diabetes risk factors in First Nations communities likely have an important role for diabetes prevention in First Nations adults.

Diabetes prevalence, incidence and mortality in First Nations and other people in Ontario, 1995-2014: a population-based study using linked administrative data.

BACKGROUND: Diabetes mellitus is an established health concern in First Nations communities and is associated with complex influences of colonization. This study, a partnership between First Nations and academic researchers, was undertaken to determine patterns of diabetes prevalence, incidence and mortality in Ontario. METHODS: Using health services and population data from Ontario for 1995 to 2014, linked with the federal Indian Register, we calculated age- and sex-adjusted annual estimates of diabetes prevalence, incidence and mortality for First Nations people (living within and outside First Nations communities) and other people in Ontario. We also examined age- and sex-specific crude diabetes prevalence. RESULTS: Between 1995 and 2014, the prevalence of diabetes increased and the incidence decreased somewhat in all populations. Both prevalence and incidence were substantially higher among First Nations people than among other people in Ontario. In particular, First Nations women had higher prevalence than other women (4.2% v. 1.6% for ages 20-34 yr and 17.6% v. 6.0% for ages 35-49 yr). The lifetime risk of diabetes was higher among First Nations people than among other people in Ontario (57.0%, 95% confidence interval [CI] 56.3%-57.6% v. 44.5%, 95% CI 44.4%-44.6%). Over time, all-cause mortality for those with diabetes declined but remained consistently higher for First Nations people than for other people in Ontario. INTERPRETATION: Diabetes is more common among First Nations people than among other people in Ontario, particularly at younger ages and in women. First Nations-led approaches to address the high prevalence of diabetes in younger First Nations women have the potential to improve metabolic health across generations.

Prevalence, incidence and outcomes of diabetes in Ontario First Nations children: a longitudinal population-based cohort study.

BACKGROUND: First Nations people are known to have a higher risk of childhood-onset type 2 diabetes, yet population-level data about diabetes in First Nations children are unavailable. In a partnership between Chiefs of Ontario and academic researchers, we describe the epidemiologic features and outcomes of diabetes in First Nations children in Ontario. METHODS: We created annual cohorts from 1995/96 to 2014/15 using data from the Registered Persons Database linked with the federal Indian Register. We used the Ontario Diabetes Database to identify children with all types of diabetes and calculated the prevalence and incidence for First Nations children and other children in Ontario. We describe glycemic control in First Nations children and other children in 2014. RESULTS: In 2014/15, there were 254 First Nations children and 10 144 other children with diagnosed diabetes in Ontario. From 1995/96 to 2014/15, the prevalence increased from 0.17 to 0.57 per 100 children, and the annual incidence increased from 37 to 94 per 100 000 per year among First Nations children. In 2014/15, the prevalence of diabetes was 0.62/100 among First Nations girls and 0.36/100 among other girls. The mean glycosylated hemoglobin level among First Nations children was 9.1% (standard deviation 2.7%) and for other children, 8.5% (standard deviation 2.1%). INTERPRETATION: First Nations children have substantially higher rates of diabetes than non-Aboriginal children in Ontario; this is likely driven by an increased incidence of type 2 diabetes and increased risk for diabetes among First Nations girls. There is an urgent need for strategies to address modifiable factors associated with the risk of diabetes, improve access to culturally sensitive diabetes care and improve outcomes for First Nations children.

Peripheral arterial disease in Ontario First Nations people with diabetes: a longitudinal population-based cohort study.

BACKGROUND: Peripheral arterial disease is an important vascular complication of diabetes that may lead to lower-extremity amputation. We aimed to compare the treatment and complications of peripheral arterial disease between First Nations people and other people in Ontario with diabetes. METHODS: Using health care administrative databases, we identified annual cohorts, from 1995/96 to 2014/15, of all people aged 20-105 years in Ontario with a diagnosis of diabetes. We used the Indian Register to identify those who were First Nations people and compared them to all other people in Ontario. We identified revascularization procedures (angioplasty or bypass surgery) and lower-extremity amputation procedures in the 2 populations and determined the mortality rate among those who had had lower-extremity amputation. RESULTS: First Nations people received revascularization procedures at a rate comparable to that for other people in Ontario. However, they had lower-extremity amputation procedures at 3-5 times the frequency for other Ontario residents. First Nations people had higher mortality than other people in Ontario after lower-extremity amputation (adjusted hazard ratio 1.15, 95% confidence interval 1.05-1.26), with median survival of 3.5 years versus 4.1 years. INTERPRETATION: First Nations people in Ontario had a markedly increased risk for lower-extremity amputation compared to other people in Ontario, and their mortality rate after amputation was 15% higher. Future research is needed to understand what barriers First Nations people face to receive adequate peripheral arterial disease care and what interventions are necessary to achieve equitable outcomes of peripheral arterial disease for First Nations people in Ontario.

Trends in cardiovascular care and event rates among First Nations and other people with diabetes in Ontario, Canada, 1996-2015.

BACKGROUND: Rates of cardiovascular disease among people with diabetes have declined over the last 20-30 years. To determine whether First Nations people have experienced similar declines, we compared time trends in rates of cardiac event and disease management among First Nations people with diabetes and other people with diabetes in Ontario, Canada. METHODS: We conducted a retrospective cohort study of patients aged 20 to 105 years with diabetes between 1996 and 2015, using linked health administrative databases. Outcomes compared were the annual incidence of each admission to hospital for myocardial infarction and heart failure, and death owing to ischemic heart disease. Management indicators were coronary revascularization and prescription rates for cardioprotective medications. Overall rates and annual percent changes were compared using Poisson regression. RESULTS: Incidence rates for all cardiac outcomes decreased over the study period. The greatest relative annual decline among First Nations men and women were observed in ischemic heart disease death (4.4%, 95% confidence interval [CI] 3.0 to 5.9) and heart failure (5.4%, 95% CI 4.5 to 6.4), respectively. Among other men and women, the greatest annual declines were seen in ischemic heart disease death (6.3%, 95% CI 6.1 to 6.5 and 7.3%, 95% CI 7.1 to 7.6, respectively). However, all absolute cardiac event rates were higher among First Nations people (p < 0.001). Coronary artery revascularization procedures and prescriptions for cardioprotective medications increased among First Nations people, while only prescriptions increased among other people. INTERPRETATION: Over the last 20 years, the incidence of cardiac events has declined among First Nations people with diabetes, but remains higher than other people with diabetes in Ontario. For continued reductions in incidence, future efforts need to recognize First Nations people's unique social and cultural determinants of health.

Healthcare resource utilization and costs among patients with direct oral anticoagulant or warfarin-related major bleeding.

INTRODUCTION: Direct oral anticoagulants (DOACs) have expanded the options for antithrombotic therapy. DOAC-related major bleeds are associated with favorable outcomes compared to warfarin in clinical trials and routine practice. However, it is unclear whether management of DOAC-associated major bleeding incurs higher resource utilization and costs. MATERIALS AND METHODS: We screened medical records of patients ≥ 66 years with atrial fibrillation admitted to one of five tertiary care hospitals in Ontario, Canada with a hemorrhage. We abstracted bleeds involving DOACs or warfarin and linked them to administrative databases to capture length of hospital stay, blood product use, procedural interventions, intensive care unit (ICU) utilization and related direct medical costs. To control for confounders, multivariate logistic and linear regressions were used for binary and linear outcomes respectively. RESULTS: Among 19,061 records screened, 1978 (10.4%) cases involving 1632 patients met criteria of oral anticoagulant-associated bleeding. Baseline characteristics between DOAC and warfarin groups were similar. Blood product costs were higher for DOACs (all comparisons DOACs vs. warfarin, $1456 vs. $1109, mean difference $347, 95% CI $185 to $509), but length of stay and ICU use were similar. Mean direct medical costs did not differ ($9217 vs. $10,790, adjusted relative ratio 0.94, 95% CI 0.84-1.05). CONCLUSIONS: Prior to introduction of DOAC-specific reversal agents, resource utilization and medical costs were comparable between DOAC- and warfarin-associated major bleeds, despite marginally higher blood product costs incurred by the former. Resource intensity associated with anticoagulant-related bleeding remains high, and our data provide measures for cost-effectiveness evaluation of emerging DOAC antidotes.