Single-dose Effectiveness of Mpox Vaccine in Quebec, Canada: Test-negative Design With and Without Adjustment for Self-reported Exposure Risk.

INTRODUCTION: During the 2022 mpox outbreak, the province of Quebec, Canada, prioritized first doses for pre-exposure vaccination of people at high mpox risk, delaying second doses due to limited supply. We estimated single-dose mpox vaccine effectiveness (VE) adjusting for virus exposure risk based only on surrogate indicators available within administrative databases (eg, clinical record of sexually transmitted infections) or supplemented by self-reported risk factor information (eg, sexual contacts). METHODS: We conducted a test-negative case-control study between 19 June and 24 September 2022. Information from administrative databases was supplemented by questionnaire collection of self-reported risk factors specific to the 3-week period before testing. Two study populations were assessed: all within the administrative databases (All-Admin) and the subset completing the questionnaire (Sub-Quest). Logistic regression models adjusted for age, calendar-time and exposure-risk, the latter based on administrative indicators only (All-Admin and Sub-Quest) or with questionnaire supplementation (Sub-Quest). RESULTS: There were 532 All-Admin participants, of which 199 (37%) belonged to Sub-Quest. With exposure-risk adjustment based only on administrative indicators, single-dose VE estimates were similar among All-Admin and Sub-Quest populations at 35% (95% confidence interval [CI]:-2 to 59) and 30% (95% CI:-38 to 64), respectively. With adjustment supplemented by questionnaire information, the Sub-Quest VE estimate increased to 65% (95% CI:1-87), with overlapping confidence intervals. CONCLUSIONS: Using only administrative data, we estimate one vaccine dose reduced the mpox risk by about one-third; whereas, additionally adjusting for self-reported risk factor information revealed greater vaccine benefit, with one dose instead estimated to reduce the mpox risk by about two-thirds. Inadequate exposure-risk adjustment may substantially under-estimate mpox VE.

Influenza Hospitalization Burden by Subtype, Age, Comorbidity, and Vaccination Status: 2012-2013 to 2018-2019 Seasons, Quebec, Canada.

BACKGROUND: Influenza immunization programs aim to reduce the risk and burden of severe outcomes. To inform optimal program strategies, we monitored influenza hospitalizations over 7 seasons, stratified by age, comorbidity, and vaccination status. METHODS: We assembled data from 4 hospitals involved in an active surveillance network with systematic collection of nasal samples and polymerase chain reaction testing for influenza virus in all patients admitted through the emergency department with acute respiratory infection during the 2012-2013 to 2018-2019 influenza seasons in Quebec, Canada. We estimated seasonal, population-based incidence of influenza-associated hospitalizations by subtype predominance, age, comorbidity, and vaccine status, and derived the number needed to vaccinate to prevent 1 hospitalization per stratum. RESULTS: The average seasonal incidence of influenza-associated hospitalization was 89/100 000 (95% confidence interval, 86-93), lower during A(H1N1) (49-82/100 000) than A(H3N2) seasons (73-143/100 000). Overall risk followed a J-shaped age pattern, highest among infants 0-5 months and adults ≥75 years old. Hospitalization risks were highest for children <5 years old during A(H1N1) but for highest adults aged ≥75 years during A(H3N2) seasons. Age-adjusted hospitalization risks were 7-fold higher among individuals with versus without comorbid conditions (214 vs 30/100 000, respectively). The number needed to vaccinate to prevent hospitalization was 82-fold lower for ≥75-years-olds with comorbid conditions (n = 1995), who comprised 39% of all hospitalizations, than for healthy 18-64-year-olds (n = 163 488), who comprised just 6% of all hospitalizations. CONCLUSIONS: In the context of broad-based influenza immunization programs (targeted or universal), severe outcome risks should be simultaneously examined by subtype, age, comorbidity, and vaccine status. Policymakers require such detail to prioritize promotional efforts and expenditures toward the greatest and most efficient program impact.

Outbreak of Highly Pathogenic Avian Influenza A(H5N1) Virus in Seals, St. Lawrence Estuary, Quebec, Canada1.

We describe an unusual mortality event caused by a highly pathogenic avian influenza (HPAI) A(H5N1) virus clade 2.3.4.4b involving harbor (Phoca vitulina) and gray (Halichoerus grypus) seals in the St. Lawrence Estuary, Quebec, Canada, in 2022. Fifteen (56%) of the seals submitted for necropsy were considered to be fatally infected by HPAI H5N1 containing fully Eurasian or Eurasian/North American genome constellations. Concurrently, presence of large numbers of bird carcasses infected with HPAI H5N1 at seal haul-out sites most likely contributed to the spillover of infection to the seals. Histologic changes included meningoencephalitis (100%), fibrinosuppurative alveolitis, and multiorgan acute necrotizing inflammation. This report of fatal HPAI H5N1 infection in pinnipeds in Canada raises concerns about the expanding host of this virus, the potential for the establishment of a marine mammal reservoir, and the public health risks associated with spillover to mammals.Nous décrivons un événement de mortalité inhabituelle causé par un virus de l'influenza aviaire hautement pathogène A(H5N1) clade 2.3.4.4b chez des phoques communs (Phoca vitulina) et gris (Halichoerus grypus) dans l'estuaire du Saint-Laurent au Québec, Canada, en 2022. Quinze (56%) des phoques soumis pour nécropsie ont été considérés comme étant fatalement infectés par le virus H5N1 de lignées eurasiennes ou de réassortiment eurasiennes/nord-américaines. Un grand nombre simultané de carcasses d'oiseaux infectés par le H5N1 sur les sites d'échouement a probablement contribué à la contamination de ces phoques. Les changements histologiques associés à cette infection incluaient : méningo-encéphalite (100%), alvéolite fibrinosuppurée et inflammation nécrosante aiguë multi-organique. Cette documentation soulève des préoccupations quant à l'émergence de virus mortels, à la possibilité d'établissement de réservoirs chez les mammifères marins, et aux risques pour la santé publique associés aux propagations du virus chez les mammifères.

Predicted 25-hydroxyvitamin D over the adult lifetime and the risk of ovarian cancer.

The evidence from previous studies of serum 25-hydroxyvitamin D (25(OH)D) and ovarian cancer risk is not conclusive. However, the 25(OH)D levels were generally only measured in late adulthood, which may not capture the etiologically relevant exposure periods. We investigated predicted 25(OH)D over the adult lifetime in relation to ovarian cancer risk in a population-based case-control study conducted from 2011 to 2016 in Montreal, Canada (n = 490 cases and 896 controls). Predicted 25(OH)D was computed using previously validated regression models. Unconditional multivariable logistic regression models were used to estimate adjusted odds ratios (aORs) and 95% CIs for average predicted 25(OH)D over the adult lifetime and ovarian cancer risk. In addition, the relative importance of different periods of past 25(OH)D exposure was explored using a weighted cumulative exposure (WCE) model. For each 20-nmol/L increase in average predicted 25(OH)D over the adult lifetime, the aOR (95% CI) was 0.73 (0.55-0.96). In WCE analyses, the inverse association was strongest for exposures 5 to 20 years and 35 to 55 years prior to diagnosis, with aORs (95% CIs) of 0.82 (0.69-0.94) and 0.79 (0.66-1.02), respectively, for each 20-nmol/L increase in predicted 25(OH)D. These results support an inverse association between 25(OH)D levels in adulthood and ovarian cancer risk. This article is part of a Special Collection on Gynecological Cancers.

Risk of Adverse Neonatal Events in Pregnancies Complicated by Severe Maternal Morbidity.

OBJECTIVE: To investigate the risk of adverse neonatal events after a pregnancy complicated by severe maternal morbidity. STUDY DESIGN: We analyzed a population-based cohort of deliveries in Quebec, Canada, between 2006 and 2021. The main exposure measure was severe maternal morbidity, comprising life-threatening conditions such as severe hemorrhage, cardiac complications, and eclampsia. The outcome included adverse neonatal events such as very preterm birth (gestational age <32 weeks), bronchopulmonary dysplasia, hypoxic ischemic encephalopathy, and neonatal death. Using log-binomial regression models, we estimated adjusted relative risks (RRs) and 95% confidence intervals (CIs) for the association between severe maternal morbidity and adverse neonatal events. RESULTS: Among 1 199 112 deliveries, 29 992 (2.5%) were complicated by severe maternal morbidity and 83 367 (7.0%) had adverse neonatal events. Severe maternal morbidity was associated with 2.96 times the risk of adverse neonatal events compared with no morbidity (95% CI 2.90-3.03). Associations were greatest for mothers who required assisted ventilation (RR 5.86, 95% CI 5.34-6.44), experienced uterine rupture (RR 4.54, 95% CI 3.73-5.51), or had cardiac complications (RR 4.39, 95% CI 3.98-4.84). Severe maternal morbidity was associated with ≥3 times the risk of neonatal death and hypoxic-ischemic encephalopathy and ≥10 times the risk of very preterm birth and bronchopulmonary dysplasia. CONCLUSIONS: Severe maternal morbidity is associated with an elevated risk of adverse neonatal events. Better prevention of severe maternal morbidity may help reduce burden of severe neonatal morbidity.

Impact of new direct-acting antiviral therapy on the prevalence and undiagnosed proportion of chronic hepatitis C infection.

BACKGROUND: Patients with chronic hepatitis C (CHC) can be cured with the new highly effective interferon-free combination treatments (DAA) that were approved in 2014. However, CHC is a largely silent disease, and many individuals are unaware of their infections until the late stages of the disease. The impact of wider access to effective treatments and improved awareness of the disease on the number of infections and the number of patients who remain undiagnosed is not known in Canada. Such evidence can guide the development of strategies and interventions to reduce the burden of CHC and meet World Health Organization's (WHO) 2030 elimination targets. The purpose of this study is to use a back-calculation framework informed by provincial population-level health administrative data to estimate the prevalence of CHC and the proportion of cases that remain undiagnosed in the three most populated provinces in Canada: British Columbia (BC), Ontario and Quebec. METHODS: We have conducted a population-based retrospective analysis of health administrative data for the three provinces to generate the annual incidence of newly diagnosed CHC cases, decompensated cirrhosis (DC), hepatocellular carcinoma (HCC) and HCV treatment initiations. For each province, the data were stratified in three birth cohorts: individuals born prior to 1945, individuals born between 1945 and 1965 and individuals born after 1965. We used a back-calculation modelling approach to estimate prevalence and the undiagnosed proportion of CHC. The historical prevalence of CHC was inferred through a calibration process based on a Bayesian Markov chain Monte Carlo (MCMC) algorithm. The algorithm constructs the historical prevalence of CHC for each cohort by comparing the model-generated outcomes of the annual incidence of the CHC-related health events against the data set of observed diagnosed cases generated in the retrospective analysis. RESULTS: The results show a decreasing trend in both CHC prevalence and undiagnosed proportion in BC, Ontario and Quebec. In 2018, CHC prevalence was estimated to be 1.23% (95% CI: .96%-1.62%), .91% (95% CI: .82%-1.04%) and .57% (95% CI: .51%-.64%) in BC, Ontario and Quebec respectively. The CHC undiagnosed proportion was assessed to be 35.44% (95% CI: 27.07%-45.83%), 34.28% (95% CI: 26.74%-41.62%) and 46.32% (95% CI: 37.85%-52.80%) in BC, Ontario and Quebec, respectively, in 2018. Also, since the introduction of new DAA treatment in 2014, CHC prevalence decreased from 1.39% to 1.23%, .97% to .91% and .65% to .57% in BC, Ontario and Quebec respectively. Similarly, the CHC undiagnosed proportion decreased from 38.78% to 35.44%, 38.70% to 34.28% and 47.54% to 46.32% in BC, Ontario and Quebec, respectively, from 2014 to 2018. CONCLUSIONS: We estimated that the CHC prevalence and undiagnosed proportion have declined for all three provinces since the new DAA treatment has been approved in 2014. Yet, our findings show that a significant proportion of HCV cases remain undiagnosed across all provinces highlighting the need to increase investment in screening. Our findings provide essential evidence to guide decisions about current and future HCV strategies and help achieve the WHO goal of eliminating hepatitis C in Canada by 2030.

Identification and Management of Pelvic Fractures in Prehospital and Emergency Department Settings.

INTRODUCTION: This study aims to describe the characteristics of patients with a pelvic fracture treated at a level 1 trauma center, the proportion of prehospital undertriage and the use of pelvic circumferential compression device (PCCD). METHODS: This is a retrospective cohort study. Prehospital and inhospital medical records of adults (≥16 y old) with a pelvic fracture who were treated at Hopital de l'Enfant-Jesus-CHU de Québec (Quebec City, Canada), a university-affiliated level 1 trauma center, between September 01, 2017 and September 01, 2021 were reviewed. Isolated hip or pubic ramus fracture were excluded. Data are presented using proportions and means with standard deviations. RESULTS: A total of 228 patients were included (males: 62.3%; mean age: 54.6 [standard deviation 21.1]). Motor vehicle collision (47.4%) was the main mechanism of injury followed by high-level fall (21.5%). Approximately a third (34.2%) needed at least one blood transfusion. Compared to those admitted directly, transferred patients were more likely to be male (73.0% versus 51.3%, P < 0.001) and to have a surgical procedure performed at the trauma center (71.3% versus 46.9%, P < 0.001). The proportion of prehospital undertriage was 22.6%. Overall, 17.1% had an open-book fracture and would have potentially benefited from a prehospital PCCD. Forty-six transferred patients had a PCCD applied at the referral hospital of which 26.1% needed adjustment. CONCLUSIONS: Pelvic fractures are challenging to identify in the prehospital environment and are associated with a high undertriage of 22.6%. Reducing undertriage and optimizing the use of PCCD are key opportunities to improve care of patients with a pelvic fracture.

Nunavimmi puvakkut kaggutimik aanniaqarniq: Qanuilirqitaa? Lung cancer in Nunavik: How are we doing? A retrospective matched cohort study.

BACKGROUND: Whether Inuit in Canada experience disparities in lung cancer survival remains unknown. When requiring investigation and treatment for lung cancer, all residents of Nunavik, the Inuit homeland in Quebec, are sent to the McGill University Health Centre (MUHC), in Montréal. We sought to compare survival among patients with lung cancer at the MUHC, who were residents of Nunavik and Montréal, Quebec, respectively. METHODS: We conducted a retrospective cohort study. Using lung cancer registry data, we identified Nunavik residents with histologically confirmed lung cancer diagnosed between 2005 and 2017. We aimed to match 2 Montréal residents to each Nunavik resident on sex, age, calendar year of diagnosis, and histology (non-small cell lung cancer v. small cell lung cancer). We reviewed medical records for data on additional patient characteristics and treatment, and obtained vital status from a provincial registry. We compared survival using Kaplan-Meier analysis and Cox proportional hazards regression. RESULTS: We included 95 residents of Nunavik and 185 residents of Montréal. For non-small cell lung cancer, median survival times were 321 (95% confidence interval [CI] 184-626) days for Nunavik (n = 71) and 720 (95% CI 536-1208) days for Montréal residents (n = 141). For small cell lung cancer, median survival times were 190 (95% CI 159-308) days for Nunavik (n = 24) and 270 (95% CI 194-766) days for Montréal residents (n = 44). Adjusting for matching variables, stage, performance status, and comorbidity, Nunavik residents had a higher hazard of death (hazard ratio 1.68, 95% CI 1.17-2.41). INTERPRETATION: Nunavik residents experience disparities in survival after lung cancer diagnosis. Although studies in other Inuit Nunangat regions are needed, our findings point to an urgent need to ensure that interventions aimed at improving lung cancer survival, including lung cancer screening, are accessible to Inuit Nunangat residents.

Switching from a 2-dose to a 1-dose program of gender-neutral routine vaccination against human papillomavirus in Canada: a mathematical modelling analysis.

BACKGROUND: Worldwide, countries are examining whether to implement 1-dose human papillomavirus (HPV) vaccination instead of using 2 doses. To inform policy, we sought to project the population-level impact and efficiency of switching from 2-dose to 1-dose gender-neutral routine HPV vaccination in Canada. METHODS: We used HPV-ADVISE, an individual-based transmission-dynamic model of HPV infections and diseases, to mathematically model vaccination programs in 2 provinces, Quebec, a province with high HPV vaccination coverage (around 85%), and Ontario, which has lower coverage (around 65%). We examined non-inferior and pessimistic scenarios of the efficacy (vaccine efficacy of 98% or 90%) and average vaccine duration (lifelong, 30 yr, or 25 yr) of 1 dose compared with 2 doses (98% vaccine efficacy, lifelong vaccine duration). Our main outcomes were the relative reduction in HPV-16 (by sex) and cervical cancers, and the number of doses needed to prevent 1 cervical cancer. RESULTS: Our model projected that 1-dose HPV vaccination would avert a similar number of cervical cancers as 2 doses in Canada, under various scenarios. Under the most pessimistic scenario (25-yr vaccine duration), 1-dose vaccination would avert fewer cervical cancers than 2 doses, by about 3 percentage points over 100 years. All 1-dose scenarios were projected to lead to elimination of cervical cancer (< 4 cervical cancers/100 000 female-years) and to be a substantially more efficient use of vaccine doses than a 2-dose scenario (1-dose v. no vaccination = 800-1000 doses needed to prevent 1 cervical cancer; incremental doses for 2-dose v. 1-dose vaccination > 10 000 doses needed to prevent 1 additional cervical cancer). INTERPRETATION: If the average duration of 1-dose protection is longer than 25 years, a 1-dose HPV vaccination program would protect those vaccinated during their peak ages of sexual activity and prevent a similar number of HPV-related cancers as a 2-dose program, while being a more efficient use of vaccine doses.

Multimorbidity prevalence and health outcome prediction: assessing the impact of lookback periods, disease count, and definition criteria in health administrative data at the population-based level.

BACKGROUND: Health administrative databases play a crucial role in population-level multimorbidity surveillance. Determining the appropriate retrospective or lookback period (LP) for observing prevalent and newly diagnosed diseases in administrative data presents challenge in estimating multimorbidity prevalence and predicting health outcome. The aim of this population-based study was to assess the impact of LP on multimorbidity prevalence and health outcomes prediction across three multimorbidity definitions, three lists of diseases used for multimorbidity assessment, and six health outcomes. METHODS: We conducted a population-based study including all individuals ages > 65 years on April 1st, 2019, in Québec, Canada. We considered three lists of diseases labeled according to the number of chronic conditions it considered: (1) L60 included 60 chronic conditions from the International Classification of Diseases (ICD); (2) L20 included a core of 20 chronic conditions; and (3) L31 included 31 chronic conditions from the Charlson and Elixhauser indices. For each list, we: (1) measured multimorbidity prevalence for three multimorbidity definitions (at least two [MM2+], three [MM3+] or four (MM4+) chronic conditions); and (2) evaluated capacity (c-statistic) to predict 1-year outcomes (mortality, hospitalisation, polypharmacy, and general practitioner, specialist, or emergency department visits) using LPs ranging from 1 to 20 years. RESULTS: Increase in multimorbidity prevalence decelerated after 5-10 years (e.g., MM2+, L31: LP = 1y: 14%, LP = 10y: 58%, LP = 20y: 69%). Within the 5-10 years LP range, predictive performance was better for L20 than L60 (e.g., LP = 7y, mortality, MM3+: L20 [0.798;95%CI:0.797-0.800] vs. L60 [0.779; 95%CI:0.777-0.781]) and typically better for MM3 + and MM4 + definitions (e.g., LP = 7y, mortality, L60: MM4+ [0.788;95%CI:0.786-0.790] vs. MM2+ [0.768;95%CI:0.766-0.770]). CONCLUSIONS: In our databases, ten years of data was required for stable estimation of multimorbidity prevalence. Within that range, the L20 and multimorbidity definitions MM3 + or MM4 + reached maximal predictive performance.

Omicron incidence and seroprevalence among children in Montreal, Canada, in early 2023: final results from the longitudinal EnCORE serology study.

Since early 2022, routine testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on symptoms and exposure history has largely ceased in Canada. Consequently, seroprevalence studies, particularly longitudinal studies, have become critical for monitoring the rate of incident SARS-CoV-2 infections and the proportion of the population with evidence of immunity. EnCORE is a longitudinal SARS-CoV-2 seroprevalence study comprising five rounds of serology testing from October 2020 to June 2023, in a sample of 2- to 17-year-olds (at baseline), recruited from daycares and schools in four neighbourhoods of Montreal, Canada. We report on SARS-CoV-2 incidence and seroprevalence among the 509 participants in the fifth and final round of the study. Seroprevalence of antibodies from either infection or vaccination was 98% (95 per cent confidence interval [CI]: 97, 99). The infection-acquired seroprevalence was 78% (95% CI: 73-82), and the incidence rate was 113 per 100 person-years (95% CI: 94-132), compared to the seroprevalence of 58% and the incidence rate of 133 per 100 person-years, respectively, in the fourth round of testing (mid-late 2022). Of the 131 participants newly seropositive for infection in Round 4, only 18 were seronegative for infection in Round 5 (median follow-up: 326 days).

Congenital anomalies during Covid-19: artifact of surveillance or a real TORCH?

Infections in the first trimester of pregnancy can be teratogenic, but the possibility that Covid-19 could lead to birth defects is unclear. We examined whether SARS-CoV-2 infection during pregnancy or exposure to pandemic conditions were associated with the risk of congenital anomalies. We carried out a retrospective study of 420,222 neonates born in Quebec, Canada in two time periods: prepandemic (January 1, 2017 to March 12, 2020) vs. pandemic (March 13, 2020 to March 31, 2022). We classified pandemic births as early (first trimester completed before the pandemic) or late (first trimester during the pandemic), and identified patients with SARS-CoV-2 infections during pregnancy. We applied (1) adjusted log-binomial regression models to assess the association between SARS-CoV-2 infection and congenital anomalies, and (2) autoregressive interrupted time series regression to analyze temporal trends in the monthly number of defects in all patients regardless of infection. In total, 29,263 newborns (7.0%) had a congenital anomaly. First trimester SARS-CoV-2 infections were not associated with a greater risk of birth defects compared with no infection (RR 1.07, 95% CI 0.59-1.95). However, births during the late pandemic period were more likely to be diagnosed with congenital microcephaly compared with prepandemic births (RR 1.44, 95% CI 1.21-1.71). Interrupted time series analysis confirmed that the frequency of microcephaly increased during the late pandemic period, whereas other anomalies did not. We conclude that Covid-19 is likely not teratogenic, but enhanced surveillance of anomalies among late pandemic births may have heightened the detection of infants with microcephaly.

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.

Changes in industrial air pollution and the onset of childhood asthma in Quebec, Canada.

Ambient air pollution has been associated with asthma onset and exacerbation in children. Whether improvement in air quality due to reduced industrial emissions has resulted in improved health outcomes such as asthma in some localities has usually been assessed indirectly with studies on between-subject comparisons of air pollution from all sources and health outcomes. In this study we directly assessed, within small areas in the province of Quebec (Canada), the influence of changes in local industrial fine particulate matter (PM2.5), nitrogen dioxide (NO2), and sulfur dioxide (SO2) concentrations, on changes in annual asthma onset rates in children (≤12 years old) with a longitudinal ecological design. We identified the yearly number of new cases of childhood asthma in 1282 small areas (census tracts or local community service centers) for the years 2002, 2004, 2005, 2006, and 2015. Annual average concentrations of industrial air pollutants for each of the geographic areas, and three sectors (i.e., pulp and paper mills, petroleum refineries, and metal smelters) were estimated by the Polair3D chemical transport model. Fixed-effects negative binomial models adjusted for household income were used to assess associations; additional adjustments for environmental tobacco smoke, background pollutant concentrations, vegetation coverage, and sociodemographic characteristics were conducted in sensitivity analyses. The incidence rate ratios (IRR) for childhood asthma onset for the interquartile increase in total industrial PM2.5, NO2, and SO2 were 1.016 (95% confidence interval, CI: 1.006-1.026), 1.063 (1.045-1.090), and 1.048 (1.031-1.080), respectively. Positive associations were also found with pollutant concentrations from most individual sectors. Results suggest that changes in industrial pollutant concentrations influence childhood asthma onset rates in small localities.

Estimating the heat-related mortality and morbidity burden in the province of Quebec, Canada.

BACKGROUND: As climate change increases the frequency and intensity of extreme heat events, there is an urgent need to quantify the heat-related health burden. However, most past studies have focussed on a single health outcome (mainly mortality) or on specific heatwaves, thus providing limited knowledge of the total pressure heat exerts on health services. OBJECTIVES: This study aims to quantify the heat-related mortality and morbidity burden for five different health outcomes including all-cause mortality, hospitalizations, emergency department (ED) visits, ambulance transports and calls to a health hotline, using the province of Quebec (Canada) as a case study. METHODS: A two-step statistical analysis was employed to estimate regional heat-health relationships using Distributed Lag Non-Linear Models (DLNM) and pooled estimates using a multivariate meta-regression. Heat burden was quantified by attributable fraction (AF) and attributable number (AN) for two temperature ranges: all heat (above the minimum mortality/morbidity temperature) and extreme heat (above the 95th percentile of temperature). RESULTS: Higher temperatures were associated with greater risk ratios for all health outcomes studied, but at different levels. Significant AF ranging from 2 to 3% for the all heat effect and 0.4-1.0% for extreme heat were found for all health outcomes, except for hospitalizations that had an AF of 0.1% for both heat exposures. The estimated burden of all heat (and extreme heat) every summer across the province was 470 (200) deaths, 225 (170) hospitalizations, 36 000 (6 200) ED visits, 7 200 (1 500) ambulance transports and 15 000 (3 300) calls to a health hotline, all figures significant. DISCUSSION: This new knowledge on the total heat load will help public health authorities to target appropriate actions to reduce its burden now and in the future. The proposed state-of-the-art framework can easily be applied to other regions also experiencing the adverse effects of extreme heat.

Care trajectories and transitions at the end of life: a population-based cohort study.

BACKGROUND: End-of-life periods are often characterised by suboptimal healthcare use (HCU) patterns in persons aged 65 years and older, with negative effects on health and quality of life. Understanding care trajectories (CTs) and transitions in this period can highlight potential areas of improvement, a subject yet only little studied. OBJECTIVE: To propose a typology of CTs, including care transitions, for older individuals in the 2 years preceding death. DESIGN: Retrospective cohort study. METHODS: We used multidimensional state sequence analysis and data from the Care Trajectories-Enriched Data (TorSaDE) cohort, a linkage between a Canadian health survey and Quebec health administrative data. RESULTS: In total, 2080 decedents were categorised into five CT groups. Group 1 demonstrated low HCU until the last few months, whilst group 2 showed low HCU over the first year, followed by a steady increase. A gradual increase over the 2 years was observed for groups 3 and 4, though more pronounced towards the end for group 3. A persistent high HCU was observed for group 5. Groups 2 and 4 had higher proportions of cancer diagnoses and palliative care, as opposed to comorbidities and dementia for groups 3 and 5. Overall, 68.4% of individuals died in a hospital, whilst 27% received palliative care there. Care transitions increased rapidly towards the end, most notably in the last 2 weeks. CONCLUSION: This study provides an understanding of the variability of CTs in the last two years of life, including place of death, a critical step towards quality improvement.

Association between low-carbohydrate-diet score, glycemia and cardiovascular risk factors in adults with type 1 diabetes.

BACKGROUND AND AIMS: Low-carbohydrate-diets (LCDs) are gaining popularity in individuals with type 1 diabetes (T1D). However, the impact of such diets on glycemia and cardiovascular risk factors is debated. This study aims to evaluate associations between low-carbohydrate intakes using LCD score with glycemia and cardiovascular risk factors (lipid profile) in adults with T1D or LADA in Québec, Canada. METHODS AND RESULTS: This is a cross-sectional study using data collected in the BETTER registry (02/2019 and 04/2021) including self-reported 24-h dietary recalls to calculate LCD scores, waist circumference, level-2 and level-3 hypoglycemic episodes and measured biochemical data (HbA1c, LDL-cholesterol and non-HDL-cholesterol). Participants were divided into quartiles (Q) based on LCD scores. Two hundred eighty-five adults (aged 48.2 ± 15.0 years; T1D duration 25.9 ± 16.2 years) were included. Categorical variables underwent Chi-squared/Fisher's Exact tests, while continuous variables underwent ANOVA tests. Mean carbohydrate intake ranged from 31.2 ± 6.9% (Q1) to 56.5 ± 6.8% (Q4) of total daily energy. Compared to Q4, more people in Q1 reported HbA1c ≤ 7% [≤53.0 mmol/mol] (Q1: 53.4% vs. Q4: 29.4%; P = 0.011). The same results were found in the models adjusted for age, sex and T1D duration. A greater proportion of participants in Q1 never experienced level-3 hypoglycemia compared to Q3 (Q1: 60.0% vs. Q3: 31.0%; P = 0.004). There were no differences across quartiles for frequency of level-2 hypoglycemia events and lipid profile (LDL-cholesterol and non-HDL-cholesterol). CONCLUSIONS: Low-carbohydrate intakes are associated with higher probabilities of reaching HbA1c target and of never having experienced level-3 hypoglycemia. No associations with level-2 hypoglycemia frequency, nor cardiovascular risk factors were observed.

Hyperemesis gravidarum and the risk of offspring morbidity: a longitudinal cohort study.

PURPOSE: Hyperemesis gravidarum has the potential to affect the long-term health of offspring. We examined whether maternal hyperemesis gravidarum was associated with the risk of hospitalization for childhood morbidity. METHODS: We conducted a longitudinal cohort study of 1,189,000 children born in Quebec, Canada, between April 2006 and March 2021. The main exposure measure was maternal hyperemesis gravidarum requiring hospitalization in the first or second trimester. The outcome was any pediatric admission between birth and 16 years of age, with follow-up ending in March 2022. We used Cox regression models adjusted for maternal and socioeconomic factors to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between maternal hyperemesis gravidarum and childhood hospitalization. RESULTS: Among 1,189,000 children, 6904 (0.6%) were exposed to maternal hyperemesis gravidarum. Hospitalization rates at age 16 years were higher for children exposed to hyperemesis gravidarum than unexposed children (47.6 vs 43.9 per 100 children). Relative to no exposure, hyperemesis gravidarum was associated with a 1.21 times greater risk of any hospitalization before 16 years (95% CI 1.17-1.26). Hyperemesis gravidarum was associated with hospitalization for neurologic (HR 1.50, 95% CI 1.32-1.71), developmental (HR 1.51, 95% CI 1.29-1.76), digestive (HR 1.40, 95% CI 1.30-1.52), and allergic disorders (HR 1.39, 95% CI 1.24-1.56). When contrasted with preeclampsia, hyperemesis gravidarum was a stronger risk factor for these outcomes. CONCLUSIONS: Maternal hyperemesis gravidarum is associated with an increased risk of childhood hospitalization, especially for neurologic, developmental, digestive, and atopic disorders. WHAT IS KNOWN: • Hyperemesis gravidarum is associated with neurodevelopmental disorders in offspring. • However, the effect of hyperemesis gravidarum on other childhood morbidity is unclear. WHAT IS NEW: • In this longitudinal cohort study of 1.2 million children, maternal hyperemesis gravidarum was associated with a greater risk of hospitalization before age 16 years. • Exposure to hyperemesis gravidarum was associated with developmental, neurologic, atopic, and digestive morbidity in childhood.

Wild fish consumption and latitude as drivers of vitamin D status among Inuit living in Nunavik, northern Québec.

OBJECTIVE: To measure vitamin D status and estimate factors associated with serum 25-hydroxyvitamin D (25(OH)D) in Nunavimmiut (Inuit living in Nunavik) adults in 2017. DESIGN: Data were from Qanuilirpitaa? 2017 Nunavik Inuit Health Survey, a cross-sectional study conducted in August-October 2017. Participants underwent a questionnaire, including an FFQ, and blood samples were analysed for total serum 25(OH)D. SETTING: Nunavik, northern Québec, Canada. PARTICIPANTS: A stratified proportional model was used to select respondents, including 1,155 who identified as Inuit and had complete data. RESULTS: Geometric mean serum vitamin D levels were 65·2 nmol/l (95 % CI 62·9-67·6 nmol/l) among women and 65·4 nmol/l (95 % CI 62·3-68·7 nmol/l) among men. The weighted prevalence of serum 25(OH)D < 75 nmol/l, <50 nmol/l <30 nmol/l was 61·2 %, 30·3 % and 7·0 %, respectively. Individuals who were older, female, lived in smaller and/or more southerly communities and/or consumed more country (traditional) foods were at a reduced risk of low vitamin D status. Higher consumption of wild fish was specifically associated with increased serum 25(OH)D concentration. CONCLUSION: It is important that national, regional and local policies and programs are in place to secure harvest, sharing and consumption of nutritious and culturally important country foods like Arctic char and other wild fish species, particularly considering ongoing climate change in the Arctic which impacts the availability, access and quality of fish as food.

Predictors of Physician Follow-Up Care Among Patients Affected by an Incident Mental Disorder Episode in Quebec (Canada).

OBJECTIVES: This study identified predictors of prompt (1+ outpatient physician consultations/within 30 days), adequate (3+/90 days) and continuous (5+/365 days) follow-up care from general practitioners (GPs) or psychiatrists among patients with an incident mental disorder (MD) episode. METHODS: Study data were extracted from the Quebec Integrated Chronic Disease Surveillance System (QICDSS), which covers 98% of the population eligible for health-care services under the Quebec (Canada) Health Insurance Plan. This observational epidemiological study investigating the QICDSS from 1 April 1997 to 31 March 2020, is based on a 23-year patient cohort including 12+ years old patients with an incident MD episode (n = 2,670,133). Risk ratios were calculated using Robust Poisson regressions to measure patient sociodemographic and clinical characteristics, and prior service use, which predicted patients being more or less likely to receive prompt, adequate, or continuous follow-up care after their last incident MD episode, controlling for previous MD episodes, co-occurring disorders, and years of entry into the cohort. RESULTS: A minority of patients, and fewer over time, received physician follow-up care after an incident MD episode. Women; patients aged 18-64; with depressive or bipolar disorders, co-occurring MDs-substance-related disorders (SRDs) or physical illnesses; those receiving previous GP follow-up care, especially in family medicine groups; patients with higher prior continuity of GP care; and previous high users of emergency departments were more likely to receive follow-up care. Patients living outside the Montreal metropolitan area; those without prior MDs; patients with anxiety, attention deficit hyperactivity, personality, schizophrenia and other psychotic disorders, or SRDs were less likely to receive follow-up care. CONCLUSION: This study shows that vulnerable patients with complex clinical characteristics and those with better previous GP care were more likely to receive prompt, adequate or continuous follow-up care after an incident MD episode. Overall, physician follow-up care should be greatly improved.