The relationship between hot temperatures and hospital admissions for psychosis in adults diagnosed with schizophrenia: A case-crossover study in Quebec, Canada.

INTRODUCTION: Some studies have found hot temperatures to be associated with exacerbations of schizophrenia, namely psychoses. As climate changes faster in Northern countries, our understanding of the association between temperature and hospital admissions (HA) for psychosis needs to be deepened. OBJECTIVES: 1) Among adults diagnosed with schizophrenia, measure the relationship between mean temperatures and HAs for psychosis during summer. 2) Determine the influence of individual and ecological characteristics on this relationship. METHODS: A cohort of adults diagnosed with schizophrenia (n = 30,649) was assembled using Quebec's Integrated Chronic Disease Surveillance System (QICDSS). The follow-up spanned summers from 2001 to 2019, using hospital data from the QICDSS and meteorological data from the National Aeronautics and Space Administration's (NASA) Daymet database. In four geographic regions of the province of Quebec, a conditional logistic regression was used for the case-crossover analysis of the relationship between mean temperatures (at lags up to 6 days) and HAs for psychosis using a distributed lag non-linear model (DLNM). The analyses were adjusted for relative humidity, stratified according to individual (age, sex, and comorbidities) and ecological (material and social deprivation index and exposure to green space) factors, and then pooled through a meta-regression. RESULTS: The statistical analyses revealed a statistically significant increase in HAs three days (lag 3) after elevated mean temperatures corresponding to the 90th percentile relative to a minimum morbidity temperature (MMT) (OR 1.040; 95% CI 1.008-1.074), while the cumulative effect over six days was not statistically significant (OR 1.052; 95% IC 0.993-1.114). Stratified analyses revealed non statistically significant gradients of increasing HAs relative to increasing material deprivation and decreasing green space levels. CONCLUSIONS: The statistical analyses conducted in this project showed the pattern of admissions for psychosis after hot days. This finding could be useful to better plan health services in a rapidly changing climate.

Associations between environmental noise and myocardial infarction and stroke: Investigating the potential mediating effects of hypertension.

BACKGROUND: We investigated whether hypertension may be a mediator in the pathway linking environmental noise exposure to incident MI and stroke. METHODS: Separately for MI and stroke, we built two population-based cohorts from linked health administrative data. Participants were residents of Montreal (Canada) between 2000 and 2014, aged 45 years and older who were free of hypertension and MI or stroke at time of entry. MI, stroke and hypertension were ascertained from validated case definitions. Residential long-term environmental noise exposure, expressed as the annual mean level acoustic equivalent 24 h (LAeq24h), was estimated from a land use regression model. We performed mediation analysis based on the potential outcomes framework. We used a Cox proportional hazards model for the exposure-outcome model and a logistic regression for the exposure-mediator model. In sensitivity analysis we applied a marginal structural approach to estimate the natural direct and indirect effects. RESULTS: Each cohort included approximately 900 000 individuals, with 26 647 incident cases of MI and 16 656 incident cases of stroke. 36% of incident MI and 40% of incident stokes had previously developed hypertension. The estimated total effect per interquartile range increase (from 55.0 to 60.5 dB A) in the annual mean LAeq24h was 1.073 (95% confidence interval (CI): 1.070-1.077) for both MI for stroke. We found no evidence of exposure-mediator interaction for both outcomes. The relationships between environmental noise and MI and stroke was not mediated by hypertension. CONCLUSIONS: This population-based cohort study suggests that the main route by which environmental noise exposure may cause MI or stroke is not through hypertension.

Hot weather and risk of drowning in children: Opportunity for prevention.

The link between outdoor temperature and risk of drowning in children is poorly understood. The objective of this study was to determine the association between elevated temperature and the chance of drowning in children and adolescents. We used a case-crossover study design to assess 807 fatal and nonfatal drowning-related hospitalisations among children aged 0 to 19 years in Quebec, Canada between 1989 and 2015. The primary exposure measure was maximum temperature the day of drowning. We estimated odds ratios and 95% confidence intervals (CI) for the association of temperature with drowning by age group (<2, 2-4, 5-9, 10-19 years), adjusted for precipitation, relative humidity, and holidays. Elevated temperature was associated with greater odds of drowning. Compared with 15 °C, a temperature of 30 °C was associated with 6 times the chance of drowning between 0 and 19 years of age (95% CI 4.40-8.16). The association was not modified by characteristics such as age or location of drowning. Relative to 15 °C, a temperature of 30 °C was associated with 3.75 times the odds of drowning in pools (95% CI 1.85-7.63) and 12.44 times the odds of drowning in other bodies of water (95% CI 3.53-43.81). Associations persisted even after implementation of a policy to restrict access to private pools in 2010. These findings suggest that hot weather is strongly associated with the risk of drowning in children aged 0 to 19 years. Interventions to prevent drowning in children should be enhanced during hot days, and not only around pools.

Exposure to guideline-recommended drugs after a first acute myocardial infarction in older adults: does deprivation matter?

BACKGROUND: Inequities between guideline-recommended drugs (GRD) exposure and socioeconomic status might exist. The objective was to assess the association between a material and a social deprivation index and GRD exposure following a first acute myocardial infarction (AMI) in older adults in the province of Quebec. METHODS: We conducted a retrospective cohort study using the Quebec Integrated Chronic Disease Surveillance System. Elderly ≥66 years, hospitalized for a first AMI between January 1, 2006, and December 31, 2011 and covered by the public drug plan were identified. Exposure to GRD (i.e. simultaneous use of 1) antiplatelet, 2) beta-blocker, 3) lipid-lowering and 4) angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker drugs) was assessed 30 and 365 days following hospital discharge. Associations between deprivation index and GRD exposure were estimated with log-binomial regressions adjusting for potential confounders. RESULTS: Exposure to GRD was 52.2% and 48.0%, 30 and 365 days after hospital discharge, respectively. No statistically significant association was observed in multivariate analysis for both time points. Thirty days post hospital discharge, adjusted prevalence ratio of non-exposure to GRD was 0.98 (95% confidence interval [CI]: 0.95-1.02) for most materially deprived vs. least deprived and 1.04 (95% CI: 0.99-1.08) for most socially deprived vs. least deprived. Similar results were observed for 365 days. CONCLUSION: Exposure to GRD after a first urgent AMI among older adults insured by the public drug plan in the province of Quebec is relatively low. Reasons and risk groups for this low exposure should be studied to improve secondary prevention. However, results suggest equitable access to GRD, regardless of deprivation.

Air pollution from industries and asthma onset in childhood: A population-based birth cohort study using dispersion modeling.

BACKGROUND: Despite evidence that ambient air pollution may play a role in the development of asthma, little is known about the potential contribution of industrial emissions. OBJECTIVE: We used a population-based birth cohort to investigate the association between asthma onset in childhood and residential exposure to industrial emissions, estimated from atmospheric dispersion modeling. METHODS: The study population comprised all children born in the province of Quebec, Canada, 2002-2011. Asthma onset were ascertained from health administrative databases with validated algorithms. We used atmospheric dispersion modeling to develop time-varying annual mean concentration of ambient PM2.5, NO2 and SO2 at participants' residence from industries. For each pollutant, we assessed the association between industrial emissions exposure and childhood asthma onset using Cox proportional hazard model, adjusted for sex, material and social deprivation and calendar year. Sensitivity analysis included adjusting for long-term regional and traffic-related ambient PM2.5 and NO2, and assessing potential confounding by unmeasured secondhand smoke. RESULTS: The cohort included 722,667 children and 66,559 incident cases of asthma. For all pollutants, we found a non-linear association between childhood asthma onset and residential ambient air pollutant concentration from industries, with stronger effects at lower concentrations. A change from 25th to the 75th percentile in the mean annual ambient concentration of PM2.5 (0.13 µg/m3), NO2 (1.0 µg/m3) and SO2 (1.6 µg/m3) from industrial emissions was associated with a 19% (95% CI: 17-20%), 21% (95% CI: 19-23%) and 23% (95% CI: 21-24%) increase in the risk of asthma onset in children, respectively. For PM2.5 and NO2, associations were persisting after adjustments for long-term regional PM2.5 and traffic-related NO2 ambient concentration. CONCLUSION: Residential exposure to industrial emissions estimated from dispersion modeling was associated with asthma onset in childhood. Importantly, associations were stronger at lower concentrations and independent from those of other sources, thus adding up to the burden of regional and traffic-related air pollution.

Exposure to ambient air pollutants and the onset of dementia in Québec, Canada.

BACKGROUND: Effects of air pollutants are related to oxidative stress which is also linked to the pathogenesis of dementia including Alzheimer's and related diseases. OBJECTIVE: We assessed associations between exposure to air pollutants and the onset of dementia; the association with the distance between residence and major roads was also assessed for the island of Montreal. METHODS: We created an open cohort of adults aged 65 years and older starting in 2000 and ending in 2012 in the province of Québec, Canada using linked medico-administrative databases. New cases of dementia were defined based on a validated algorithm. Annual residential levels of nitrogen dioxide (NO2) and fine particles (PM2.5) at residential levels were estimated for each year of follow up using estimates based on satellite images and ground air monitoring data. Hazard ratios (HRs) were assessed with Extended (time dependent exposure) Cox models with age as the time axis and stratified for sex, for the annual exposure level at each residential address. Models were adjusted for the calendar year, area-wide social and material deprivation indexes and for NO2 or PM2.5; they were also indirectly adjusted for smoking. RESULTS: 1,807,133 persons (13,242,270 person-years) were followed and 199,826 developed dementia. From models (adjusted for calendar year, social and material deprivation indexes), HRs for an interquartile range (IQR) increase in time-varying exposure to NO2 (IQR 13.26 ppb), PM2.5 (IQR 3.90 µg/m³), and distance to major roads (IQR 150 m, in Montreal only), were 1.005 (CI 95% 0.994-1.017), 1.016 (CI 95% 1.003-1.028) and 0.969 (CI 95% 0.958-0.980), respectively. CONCLUSIONS: Results suggest that the onset of dementia may be related to residential exposure to PM2.5, NO2, and distance to major roads.

Frailty and health services use among Quebec seniors with non-hip fractures: a population-based study using adminsitrative databases.

BACKGROUND: The number of frail elderly will increase as the world population ageing accelerates. Since frail elders are at risk of falls, hospitalizations and disabilities, they will require more health care and services. To assess frailty prevalence using health administrative databases, to examine the association between frailty and the use of medical services and to measure the excess use of health services following a non-hip fracture across frailty levels among community-dwelling seniors. METHODS: A population-based cohort study was built from the Quebec Integrated Chronic Disease Surveillance System, including men and women ≥65 years old, non-institutionalized in the pre-fracture year. Frailty was measured using the Elders Risk Assessment (ERA) index. Multivariate Generalized Estimating Equation models were used to examine the relationship between frailty levels and health services while adjusting for covariates. The excess numbers of visits to Emergency Departments (ED) and to Primary Care Practitioners (PCP) as well as hospitalizations were also estimated. RESULTS: The cohort included 178,304 fractures. There were 13.6 and 5.2% frail and robust seniors, respectively. In the post-fracture year, the risks of ED visits, PCP visits and hospitalizations, were significantly higher in frail vs. non-frail seniors: adjusted relative risk (RR) = 2.69 [95% CI: 2.50-2.90] for ED visits, RR = 1.28 [95% CI: 1.23-1.32] for PCP visits and RR = 2.34 [95% CI: 2.14-2.55] for hospitalizations. CONCLUSION: Our results suggest that it is possible to characterize seniors' frailty status at a population level using health administrative databases. Furthermore, this study shows that non-institutionalized frail seniors require more health services after an incident fracture. Screening for frailty in seniors should be part of clinical management in order to identify those at a higher risk of needing health services.

Variation in cerebral palsy profile by socio-economic status.

AIM: Socio-economic differences in maternal and child health are well recognized, but the role of individual-level and area-level determinants in cerebral palsy (CP) phenotypes is debated. We set out to examine (1) the association between area-level and individual-level measures of socio-economic deprivation and CP phenotype among children, including subtype, severity, and comorbidities; and (2) the direct effect of area-level deprivation not mediated through individual-level deprivation. METHOD: Regional data from a provincial CP register were analyzed. The outcome of interest was CP phenotype. The area-level exposure was measured using the Pampalon Deprivation Index. Individual-level socio-economic status (SES) was determined using maternal education. We conducted multiple regression models, stratified by preterm birth, controlling for key covariates, and a mediation analysis of area-level deprivation on the association between individual SES and CP phenotype. RESULTS: A socio-economic gradient in mobility was seen in our cohort, above and beyond differences in maternal and perinatal factors. The added direct effect of area-level deprivation was seen only in children whose mothers were educated to a higher level, suggesting no additional contribution of area-level deprivation in children of mothers with a lower level of education. INTERPRETATION: Contextual socio-economic factors can impact the severity of CP. These findings indicate important areas for potential community-level or area-level public health intervention (i.e. neighborhood reinvestment, preventive measures), and suggest that neighborhood-level research in maternal and perinatal health should continue to be pursued.

Suicide in Canada: impact of injuries with undetermined intent on regional rankings.

The impact of underreporting or misclassifying suicides as injuries with undetermined intent is rarely evaluated. We assessed whether undetermined injury deaths influenced provincial rankings of suicide in Canada, using 2 735 152 Canadians followed for mortality from 1991 to 2001. We found that suicide rates increased by up to 26.5% for men and 37.7% for women after including injuries with undetermined intent, shifting provincial rankings of suicide. Attention to the stigma of suicide and to coding suicides as injuries with undetermined intent is merited for surveillance and prevention.

Effect of family medicine groups on visits to the emergency department among diabetic patients in Quebec between 2000 and 2011: a population-based segmented regression analysis.

BACKGROUND: Family Medicine Groups (FMG) were introduced in Quebec in 2002 to re-organize primary care practices and encourage inter-professional service delivery. We measured visits to the emergency department (ED) for acute complications related to diabetes as a proxy for access to and quality of primary care, before and after the reform using an open cohort of individuals diagnosed with type 1 and type 2 diabetes. METHODS: The weekly rate of ED visits between April 1, 2000 and March 31, 2012 were derived from administrative databases. We performed an interrupted segmented regression analysis to obtain the estimated and predicted rates of visits in the years following the introduction of the reform. An outcome control series of diabetic patients visiting the ED to treat appendicitis was incorporated to strengthen the study's internal validity. RESULTS: After 9 years of reform implementation, we observed a statistically significant absolute decrease of 2.12 and 2.25 ED visits per 10,000 diabetic patients per week to treat acute diabetes-related complications in urban and rural areas, respectively. However, the magnitude of the changes between the estimated and predicted rates did not differ significantly over time. No statistically significant change in the rate of ED visits for appendicitis was observed. CONCLUSION: Our findings suggest that the introduction of the FMG model produced reductions in the weekly rate of avoidable visits to the ED. Our results also imply that despite a greater proportion of the diabetes population being enrolled with FMG physicians across the province over time, the added benefit may be minimal. More studies examining this issue are needed to inform future policy.

Prevalence and incidence of Paget's disease of bone: Temporal trend over 20 years in the province of Quebec, Canada.

BACKGROUND: Paget's disease of bone (PDB) is a focal bone disorder characterized by an increased bone remodeling and an anarchic bone structure. A decline of prevalence and incidence of PDB has been observed in some countries. No epidemiological data are available on PDB in Canada. AIMS: We aimed at examining the evolution of the prevalence and incidence of PDB in Quebec (Canada) by analyzing health administrative databases. METHODS: PDB case definition relied on one or more hospitalizations, or one or more physician-billing claims with a diagnosis code of PDB. To identify incident cases, a 'run-in' period of four years (1996-1999) was used to exclude prevalent cases. For each fiscal year from 2000 to 2001 to 2019-2020 (population size 2,914,480), crude age and sex-specific prevalence and incidence rates of PDB among individuals aged ≥55 years were determined, and sex-specific rates were also standardized to the 2011 age structure of the Quebec population. Generalized linear regressions were used to test for linear changes in standardized prevalence and incidence rates. RESULTS: Over the study period, standardized prevalence of PDB has remained stable in Quebec, from 0.44 % in 2000/2001 to 0.43 % in 2019/2020 (mean change -0.002, p-value = 0.0935). For the 2019-2020 fiscal year, 13,165 men and women had been diagnosed with PDB and prevalence of PDB increased with age. Standardized incidence of PDB has decreased over time from 0.77/1000 in 2000/2001 to 0.28/1000 in 2019-2020 (mean change -0.228/year, p-value<0.0001), the incidence decreasing from 0.82/1000 to 0.37/1000 in men and from 0.76/1000 to 0.22/1000 in women, respectively. This decrease was observed in all age categories. CONCLUSION: With the exception of a slight increase in PDB prevalence up to 0.55 % in years 2005 to 2007, the prevalence of PDB has remained stable in Quebec over the past 20 years, 13,160 men and women being currently diagnosed with PDB. The incidence has decreased over time. Our results support the epidemiological changes of PDB reported in other countries.

Evolution of the burden of aortic stenosis by sex in the province of Quebec between 2006 and 2018.

OBJECTIVES: To evaluate the evolution of the burden of aortic stenosis (AS) by sex in the province of Quebec from 2006-2007 to 2018-2019 and compare the percentage of mortality between people who underwent aortic valve intervention and those who did not. METHODS: Persons aged ≥20 years were identified from the Quebec Integrated Chronic Disease Surveillance System using International Classification of Diseases and intervention codes in the hospital files. RESULTS: In 2018, the crude prevalence and incidence of AS were 0.89% (99% CI 0.89 to 0.90) (n=59 025) and 1.39 per 1000 (1.35 to 1.43) (n=9105), respectively. Age-standardised prevalence and incidence of AS diagnosis increased between 2006 and 2018 from 0.67% (0.66 to 0.68) to 0.75% (0.74 to 0.76) and from 0.91 per 1000 (0.88 to 0.95) to 1.20 per 1000 (1.17 to 1.23), respectively. Among incident AS, the age-standardised percentage of valve interventions increased from 11.7% (10.9 to 12.6) to 14.5% (13.9 to 15.3). This increase was only observed in men. The 30-day mortality was stable among patients with incident AS treated conservatively, from 6.9% (6.5 to 7.4) to 7.3% (6.9 to 7.6), and decreased from 7.6% (6.1 to 9.3) to 3.8% (3.1 to 4.7) among operated patients with incident AS. This decrease was only observed in women. However, from 2010, the age-adjusted mortality among prevalent AS tended to be higher in women. CONCLUSIONS: In the province of Quebec, age-standardised prevalence and incidence of AS diagnosis increased between 2006 and 2018. Among incident AS, there was an increase in valve intervention in men and a decrease in 30-day mortality in women who underwent valve intervention. Overall and age-standardised mortality remained higher in women.

Long-term exposure to fine particulate matter and ozone and the onset of systemic autoimmune rheumatic diseases: an open cohort study in Quebec, Canada.

OBJECTIVES: To estimate associations between fine particulate matter (PM2.5) and ozone and the onset of systemic autoimmune rheumatic diseases (SARDs). METHODS: An open cohort of over 6 million adults was constructed from provincial physician billing and hospitalization records between 2000 and 2013. We defined incident SARD cases (SLE, Sjogren's syndrome, scleroderma, polymyositis, dermatomyositis, polyarteritis nodosa and related conditions, polymyalgia rheumatic, other necrotizing vasculopathies, and undifferentiated connective tissue disease) based on at least two relevant billing diagnostic codes (within 2 years, with at least 1 billing from a rheumatologist), or at least one relevant hospitalization diagnostic code. Estimated PM2.5 and ozone concentrations (derived from remote sensing and/or chemical transport models) were assigned to subjects based on residential postal codes, updated throughout follow-up. Cox proportional hazards models with annual exposure levels were used to calculate hazard ratios (HRs) for SARDs incidence, adjusting for sex, age, urban-versus-rural residence, and socioeconomic status. RESULTS: The adjusted HR for SARDS related to one interquartile range increase in PM2.5 (3.97 µg/m3) was 1.12 (95% confidence interval 1.08-1.15), but there was no clear association with ozone. Indirectly controlling for smoking did not alter the findings. CONCLUSIONS: We found associations between SARDs incidence and PM2.5, but no relationships with ozone. Additional studies are needed to better understand interplays between the many constituents of air pollution and rheumatic diseases.

Relationships between long-term residential exposure to total environmental noise and stroke incidence.

Background: Noise has been related to several cardiovascular diseases (CVDs) such as coronary heart disease and to their risk factors such as hypertension, but associations with stroke remain under-researched, even if CVD likely share similar pathophysiologic mechanisms. Aim: The objective of the study was to examine the association between long-term residential exposure to total environmental noise and stroke incidence in Montreal, Canada. Materials and Methods: We created an open cohort of adults aged ≥45years, free of stroke before entering the cohort for the years 2000 to 2014 with health administrative data. Residential total environmental noise levels were estimated with land use regression (LUR) models. Incident stroke was based on hospital admissions. Cox hazard models with age as the time axis and time-varying exposures were used to estimate associations, which were adjusted for material deprivation, year, nitrogen dioxide, stratified for sex, and indirectly adjusted for smoking. Results: There were 9,072,492 person-years of follow-up with 47% men; 26,741 developed stroke (21,402 ischemic; 4947 hemorrhagic; 392 had both). LUR total noise level acoustic equivalent for 24 hours (LAeq24h) ranged 44 to 79 dBA. The adjusted hazard ratio (HR) for stroke (all types), for a 10-dBA increase in LAeq24h, was 1.06 [95% confidence interval (CI): 1.03-1.09]. The LAeq24h was associated with ischemic (HR per 10 dBA: 1.08; 95% CI: 1.04-1.12) but not hemorrhagic stroke (HR per 10 dBA: 0.97; 95% CI: 0.90-1.04). Conclusion: The results suggest that total environmental noise is associated with incident stroke, which is consistent with studies on transportation noise and other CVD.

Influence of social and material individual and area deprivation on suicide mortality among 2.7 million Canadians: a prospective study.

BACKGROUND: Few studies have investigated how area-level deprivation influences the relationship between individual disadvantage and suicide mortality. The aim of this study was to examine individual measures of material and social disadvantage in relation to suicide mortality in Canada and to determine whether these relationships were modified by area deprivation. METHODS: Using the 1991-2001 Canadian Census Mortality Follow-up Study cohort (N = 2,685,400), measures of individual social (civil status, family structure, living alone) and material (education, income, employment) disadvantage were entered into Cox proportional hazard models to calculate hazard ratios (HR) and 95% confidence intervals (CI) for male and female suicide mortality. Two indices of area deprivation were computed - one capturing social, and the other material, dimensions - and models were run separately for high versus low deprivation. RESULTS: After accounting for individual and area characteristics, individual social and material disadvantage were associated with higher suicide mortality, especially for individuals not employed, not married, with low education and low income. Associations between social and material area deprivation and suicide mortality largely disappeared upon adjustment for individual-level disadvantage. In stratified analyses, suicide risk was greater for low income females in socially deprived areas and males living alone in materially deprived areas, and there was no evidence of other modifying effects of area deprivation. CONCLUSIONS: Individual disadvantage was associated with suicide mortality, particularly for males. With some exceptions, there was little evidence that area deprivation modified the influence of individual disadvantage on suicide risk. Prevention strategies should primarily focus on individuals who are unemployed or out of the labour force, and have low education or income. Individuals with low income or who are living alone in deprived areas should also be targeted.

Prediction of Osteoporotic Fractures in Elderly Individuals: A Derivation and Internal Validation Study Using Healthcare Administrative Data.

In Canada and other countries, osteoporosis is monitored as part of chronic disease population surveillance programs. Although fractures are the principal manifestation of osteoporosis, very few algorithms are available to identify individuals at high risk of osteoporotic fractures in current surveillance systems. The objective of this study was to derive and validate predictive models to accurately identify individuals at high risk of osteoporotic fracture using information available in healthcare administrative data. More than 270,000 men and women aged ≥66 years were randomly selected from the Quebec Integrated Chronic Disease Surveillance System. Selected individuals were followed between fiscal years 2006-2007 and 2015-2016. Models were constructed for prediction of hip/femur and major osteoporotic fractures for follow-up periods of 5 and 10 years. A total of 62 potential predictors measurable in healthcare administrative databases were identified. Predictor selection was performed using a manual backward algorithm. The predictive performance of the final models was assessed using measures of discrimination, calibration, and overall performance. Between 20 and 25 predictors were retained in the final prediction models (eg, age, sex, social deprivation index, most of the major and minor risk factors for osteoporosis, diabetes, Parkinson's disease, cognitive impairment, anemia, anxio-depressive disorders). Discrimination of the final models was higher for the prediction of hip/femur fracture than major osteoporotic fracture and higher for prediction for a 5-year than a 10-year period (hip/femur fracture for 5 years: c-index = 0.77; major osteoporotic fracture for 5 years: c-index = 0.71; hip/femur fracture for 10 years: c-index = 0.73; major osteoporotic fracture for 10 years: c-index = 0.68). The predicted probabilities globally agreed with the observed probabilities. In conclusion, the derived models had adequate predictive performance in internal validation. As a final step, these models should be validated in an external cohort and used to develop indicators for surveillance of osteoporosis. © 2021 American Society for Bone and Mineral Research (ASBMR).

Mosquitoes Know No Borders: Surveillance of Potential Introduction of Aedes Species in Southern Québec, Canada.

Current climatic conditions limit the distribution of Aedes (Stegomyia) albopictus (Skuse, Diptera: Culicidae) in the north, but predictive climate models suggest this species could establish itself in southern Canada by 2040. A vector of chikungunya, dengue, yellow fever, Zika and West Nile viruses, the Ae. Albopictus has been detected in Windsor, Ontario since 2016. Given the potential public health implications, and knowing that Aedes spp. can easily be introduced by ground transportation, this study aimed to determine if specimens could be detected, using an adequate methodology, in southern Québec. Mosquitoes were sampled in 2016 and 2017 along the main roads connecting Canada and the U.S., using Biogent traps (Sentinel-2, Gravide Aedes traps) and ovitraps. Overall, 24 mosquito spp. were captured, excluding Ae. Albopictus, but detecting one Aedes (Stegomyia) aegypti (Skuse) specimen (laid eggs). The most frequent species among captured adults were Ochlerotatus triseriatus, Culex pipiens complex, and Ochlerotatus japonicus (31.0%, 26.0%, and 17.3%, respectively). The present study adds to the increasing number of studies reporting on the range expansions of these mosquito species, and suggests that ongoing monitoring, using multiple capture techniques targeting a wide range of species, may provide useful information to public health with respect to the growing risk of emerging mosquito-borne diseases in southern Canada.

Manuscript title: Long─term residential exposure to environmental/transportation noise and the incidence of myocardial infarction.

BACKGROUND: Cardiovascular effects of environmental noise are a growing concern. However, the evidence remains largely limited to the association between road traffic noise and hypertension and coronary heart diseases. OBJECTIVES: To investigate the association between long-term residential exposure to environmental/transportation noise and the incidence of myocardial infarction (MI) in the adult population living in Montreal. METHODS: An open cohort of adults aged 45 years old and over, living on the island of Montreal and free of MI before entering the cohort was created for the years 2000-2014 with the Quebec Integrated Chronic Disease Surveillance System; a systematic surveillance system from the Canadian province of Quebec starting in 1996. Residential noise exposure was calculated in three ways: 1) total ambient noise levels estimated by Land use regression (LUR) models; 2) road traffic noise estimated by a noise propagation model CadnaA and 3) distances to transportation sources (roads, airport, railways). Incident MI was based on diagnostic codes in hospital admission records. Cox models with time-varying exposures (age as the time axis) were used to estimate the associations with various adjustments (material deprivation indicator, calendar year, nitrogen dioxide, stratification for sex). Indirect adjustment based on ancillary data for smoking was performed. RESULTS: 1,065,414 individuals were followed (total of 9,000,443 person-years) and 40,718 (3.8%) developed MI. We found positive associations between total environmental noise, estimated by LUR models and the incidence of MI. Total noise LUR levels ranged from ~44 to ~79 dBA and varied slightly with the metric used. The adjusted hazard ratios (HRs) (also adjusted for smoking) were 1.12 (95% Confidence Intervals [CI]: 1.08-1.15), 1.11 (95%CI: 1.07-1.14) and 1.10 (95%CI: 1.06-1.14) per 10 dBA noise levels increase respectively in Level Accoustic equivalent 24 h (LAeq24 h), Level day-evening-night (Lden) and night level (Lnight). We found a borderline negative association between road noise levels estimated with CadnaA and MI (HR: 0.99 per 10 dBA; 95%CI: 0.98-1.00). Distances to major roads and highways were not associated with MI while the proximity to railways was positively associated with MI (HR for ≤100 vs > 1000 m: 1.07; 95%CI: 1.01-1.14). A negative association was found with the proximity to the airport noise exposure forecast (NEF25); HR (<1 vs >1000 m) = 0.88 (95%CI: 0.81-0.96). CONCLUSIONS: These associations suggest that exposure to total environmental noise at current urban levels may be related to the incidence of MI. Additional studies with more accurate road noise estimates are needed to explain the counterintuitive associations with road noise and specific transportation sources.

Health inequalities, deprivation, immigration and aboriginality in Canada: a geographic perspective.

OBJECTIVE: This study explores the contribution of deprivation, immigration and Aboriginal status to survival in various parts of Canada. It is hypothesized that differences in the magnitude of survival inequalities according to deprivation across Canada are attenuated when immigration and Aboriginal status are accounted for. METHODS: The study is based on a file linking the 1991 census and a follow-up of mortality from 1991 to 2001. Geographic areas are the Canadian regions, the census metropolitan areas (CMAs) of Montréal, Toronto and Vancouver as well as the metropolitan-influenced zones. Deprivation is measured through a Canadian deprivation index. Immigration is based on declared place of birth and Aboriginal status on ethnic origin, registered treaty Indian status and Band or First Nation membership. Survival is modelized through Cox regression and two sets of models are produced for every geographic area. RESULTS: Survival is associated with deprivation, immigration and Aboriginal status in most parts of Canada. After accounting for immigration and Aboriginal status, differences in the magnitude of survival inequalities related to deprivation across Canada are attenuated. Such inequalities are highly reduced in the Prairies and remote hinterland and slightly increased in the CMA of Toronto. Nevertheless, high survival inequalities related to deprivation remain in Canada, namely in the Prairies and, to a lesser degree, in British Columbia and the CMA of Vancouver. CONCLUSION: After accounting for immigration and Aboriginal status, differences in the magnitude of survival inequalities according to deprivation across Canada are attenuated but not completely eliminated.

The Potential Health Impact of an Alcohol Minimum Unit Price in Québec: An Application of the International Model of Alcohol Harms and Policies.

OBJECTIVE: Alcohol minimum unit pricing is a strategy capable of reducing alcohol-related harm from cheap alcoholic beverages. We used the International Model of Alcohol Harms and Policies (InterMAHP), an open-access alcohol harms estimator and policy scenario modeler, to estimate the potential health benefits of introducing minimum unit pricing in Québec, Canada. METHOD: Aggregated mortality and hospitalization data were obtained from official administrative sources. Alcohol sales and pricing data were obtained from the partial government retail monopoly and Nielsen. Exposure data were from the Canadian Substance Use Exposure Database. Average price changes under two minimum-unit-pricing scenarios were estimated by applying a product-level pricing analysis. The online InterMAHP tool was used to automate the estimation of observed alcohol-attributable harm and what was projected in each policy scenario. RESULTS: Alcohol was estimated to cause 2,850 deaths and 24,694 hospitalizations in Québec in 2014. Introducing minimum unit pricing of CAD$1.50 was estimated to reduce consumption by 4.4%, alcohol-attributable deaths by 5.9% (95% CI [0.2%, 11.7%]), and alcohol-attributable hospital stays by 8.4% (95% CI [3.2%, 13.7%]). Higher minimum unit pricing of CAD$1.75 was estimated to reduce alcohol-attributable deaths by 11.5% (95% CI [5.9%, 17.2%]) and alcohol-attributable hospital stays by 16.3% (95% CI [11.2%, 21.4%]). CONCLUSIONS: The results of this policy modeling study suggest that the introduction of minimum unit pricing between CAD$1.50 and $1.75 would substantially reduce the alcohol-caused burden of disease in Québec. The quantification of alcohol-caused death and disability, and the changes in these measures under two scenarios, was significantly automated by the open-access resource, InterMAHP.