Selected abstracts from the 16th Annual Epidemiology, Biostatistics and Occupational Health (EBOH) Research Day. The event was held on March 13, 2020, and was led by the Epidemiology, Biostatistics and Occupational Health Student Society. Research Day celebrates the research done by students in EBOH at McGill University. Special thanks to the abstract reviewers, presentation judges, administrative staff, faculty donors, and organizing committee, without whom this event would not have been possible.
Background: Breathing ambient Black Carbon (BC) may result in adverse health effects. To better understand and mitigate the possible health effects of exposure to BC, it is important to estimate the spatial distribution of ambient BC concentrations in cities. Through this project, models were built to estimate ambient BC concentrations in Montreal and Toronto.
Methods: BC concentrations in Montreal and Toronto were monitored during summer 2018 and winter 2019. Land use variables surrounding the monitoring locations were collected and used to build land use regression models that predicted ambient BC concentrations at the monitoring sites. The models were used to create surfaces that estimate ambient BC concentrations over the entire area of Montreal and Toronto.
Results: Mean BC concentrations varied substantially within each city with values ranging from 575.5 to 2351.5 ng/m3 in Montreal (mean = 1334.9 ng/m3; sd = 428.5) and 0 to 5646 ng/m3 in Toronto (mean = 2418.9 ng/m3; sd = 1342.0). The Montreal land use regression model explained 66% of the observed variance in BC concentrations. The Toronto model explained 79% of the observed variance.
Conclusion: The surfaces of predicted BC concentrations show high spatial variability over the modelling area. These estimates can be applied to population-based cohorts in order to evaluate population health risks and ultimately develop policy interventions to reduce exposure to air pollution and improve population health.
Background: The association between vitamin K antagonists (VKAs) and cancer is unclear, with some, but not all, observational studies reporting decreased risks of cancer overall. Conversely, some trials of direct oral anticoagulants (DOACs) suggest possible increased risks, particularly with bladder and pancreatic cancer. To date, no observational studies have been conducted to assess these possible associations. The objective of this study was to determine whether use of VKAs and DOACs is associated with cancer incidence overall and by subtype among patients with non-valvular atrial fibrillation (NVAF).
Methods: Using the Clinical Practice Research Datalink we conducted a population-based cohort study by identifying patients newly diagnosed with NVAF between 2011 and 2018. Use of VKAs and DOACs was modelled as a time-varying variable and compared with non-use, using a one-year lag for latency. We used Cox proportional hazards models to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for cancer overall and by selected subtypes.
Results: The cohort included 28,880 patients with NVAF, with 1,119 newly diagnosed cancer cases. Compared with non-use, use of VKAs was not associated with cancer overall (HR: 1.05, 95%CI: 0.90-1.21) or cancer subtype. Similarly, use of DOACs was not associated with cancer overall (HR: 1.13, 95%CI: 0.93-1.37), but an association was observed for colorectal cancer (HR: 1.74, 95%CI: 1.01-3.00), and pancreatic cancer generated an elevated HR with a wide CI (HR: 2.13, 95%CI: 0.72-6.34).
Conclusions: This first real-world study suggests that use of anticoagulants is not associated with cancer overall in patients with NVAF, although associations observed between DOACs and colorectal and pancreatic cancer warrant further study.
Background: Increasing temperatures worldwide have caused more frequent, drastic and long-lasting extreme heat events. This is a growing public health concern, as heat-related illness is potentially life-threatening and is 100% preventable. Communities can play an important role to prevent heat-related illness and death through coordinated planning and action. Several rural communities in the interior region of British Columbia (BC) experience some of the highest temperatures in the province. In 2018, the Interior Health Authority undertook the development of a Heat Alert and Response System (HARS) in collaboration with a small rural community. A community-driven, community-based approach allowed HARS to be incorporated into existing community response plans and established infrastructure. The knowledge acquired through the demonstration community supported similar collaborative planning processes in other rural communities in the interior region of BC.
Methods: The Interior Health Authority facilitated the gathering of key community stakeholders to assess community assets, plan for extreme heat and prepare for a community-supported response during a heat event. Focus was placed on the following main pillars (1) Implementation of a HARS in a small, rural community (Ashcroft, BC), (2) Outreach to additional rural communities to join the HARS initiative, (3) Development of both region-wide and community-specific communications plans, (4) Extreme heat information web page, (5) Public education and notification (including social media), and (6) Toolkit with resources to initiate a HARS.
Results: The temperature threshold was not achieved for the activation of the Heat Alert and Response System throughout the summer of 2019. Nonetheless, stakeholders expressed the importance of utilizing existing partnerships and community resources, such as physical and procedural infrastructure, in which to embed the HARS. Also, it was emphasized that the plan had to be simple, concise and focus on the community’s unique context. Educational materials that encourage individuals to take action against extreme heat was identified as the most effective means to mitigate risk in a community with limited resources.
Conclusion: The knowledge gained from the development & implementation of a rural HARS pilot project provided innovative ideas that can be applied across a Canadian context. Community-specific considerations facilitated program implementation. Therefore, the presence of an active and well-rounded group of stakeholders was found to be an essential resource for a successful HARS in a rural community.
Background: Increase in antidepressant prescription in children and adolescents has been documented in the UK since the 2000s but no information is available on recent trends. Moreover, little is known about the coprescription with other psychotropic medications.
Methods: Using the Clinical Practice Research Datalink, we defined a cohort of patients aged 5–17 years, registered with a general practitioner between 1 January 2000 and 31 December 2018. We estimated the yearly rates of patients newly treated with antidepressants using Poisson regression. We also calculated the percentage of patients with a same-day coprescription with other psychotropic medications (antipsychotics, mood stabilizers, anxiolytics, and stimulants).
Results: After a brief decline from 2000 to 2005, the rate of patients newly prescribed antidepressants increased from 2006 onwards. From 2008 to 2018, the rate increased from 254.3 to 471.2 per 100,000 person-years (rate ratio 1.97, 95% confidence interval 1.96-1.99). The rate was higher in girls and in adolescents aged 15 to 17 years during the entire study period. Selective serotonin reuptake inhibitors (SSRIs) were the most commonly prescribed antidepressant class (70% of all antidepressant prescriptions), followed by tricyclic antidepressants (TCAs). In 2018, 81% of prescriptions were for SSRIs, 17% for TCAs and 2% for other antidepressants. Overall, 5% of new users of antidepressants had at least one same-day coprescription for another psychotropic medication during the study period, from 2.62% of patients in 2000 to 6.36% in 2018. Coprescription was mostly for anxiolytics (58%) and antipsychotics (30%), and most patients had only one psychotropic drug prescribed with the antidepressant.
Conclusions: Antidepressants prescription have increased in the past two decades in children and adolescents, accompanied by a rise in coprescription for other psychotropic medications. Further research is needed to offer potential explanations for the trends observed.
Background: The purpose of this project was to investigate sex difference among consumer knowledge about product safety, effectiveness and note frequency of reading self-care product labels. This project aimed to estimate knowledge gaps among frequent users of self-care products. By determining the frequency of reading labels, Health Canada could contextualize how to redesign product labels in the future. This would allow for an improved level of knowledge among frequent users and their information-seeking behaviors.
Methods:Data were obtained from an online survey conducted among 2,502 Canadians age ≥18 years from April 18th- 26th, 2016. Respondents for this survey were selected from among those who had registered to participate in the TNS online surveys.
Results: Among the 2,477 consumers, 1,316 (53.13%) were female respondents. About 33% were frequent users. Reported lack of knowledge about safety was 80.03% among males and 80.93% among female consumers of natural health products (NHP), 66.43% among males and 67.1% among female users of non-prescription drugs (NPD), and 75.37% among male and 74.39% female users of cosmetics. Greater than 50% of the male and female frequent users reported that they were not well informed about the products. Overall, after making subgroups within the dataset, we had 820 variables. This helped understand various discourses in the context of consumer knowledge, their attitudes and their behaviors towards using self-care products.
Conclusions: A high proportion of Canadians use self-care products, yet a majority of frequent users is not knowledgeable about product properties and safety. Most consumers rely on Health Canada to oversee product safety. This project aimed to help Health Canada take measures to increase the level of consumer knowledge by 1) designing product labels that enhance the knowledge of NHP, NPD and cosmetics users and 2) by targeting popularly accessed sources of information.
Background: In 2015, Nova Scotia Health Authority (NSHA) evaluated the state of implementation of the service delivery model for community mental health and addictions (CMHA) across Nova Scotia. Their report highlighted variability in service delivery across the province, the lack of a standardized provincial model, a failure to consistently meet target wait times for services, and excessive no-shows and cancellations for appointments. Based on this information, NSHA wanted an analysis of other service delivery models to inform improvements to the provincial model.
Methods: In 2019, the NSHA Mental Health and Addictions (MHA) Policy & Planning team initiated a process to review existing service delivery models to develop recommendations for NSHA MHA Tier 3 (moderate to severe) adult community services. The project entailed an environmental scan of the current state of service delivery, a literature review to identify appropriate models, the development of a matrix to present important model characteristics, and the identification of trends in the literature to inform recommendations regarding next steps.
Results: The matrix presented 35 key characteristics organized into seven themes to describe each model. Working within the limitations of the published literature, 67 models were identified and included in the matrix. These models were organized into ten main models that collectively highlighted the breadth of evidence currently available. Two complementary themes were identified through this work: strengthening capacity of primary care and increasing accessibility of services for rural populations. Overall, the evidence base was insufficient to support the recommendation of one service delivery model for NSHA CMHA adult services. However, several key models were identified that could contribute to the development of a provincial model.
Conclusions: The recommendations developed from this project were primarily for next steps to be undertaken by NSHA to move forward with the task of adopting a new service delivery model for adult CMHA services.
Background: Leptospirosis is one of the most widespread zoonotic diseases with more than 1.03 million cases and 58,900 deaths worldwide. In spite of the huge burden, routine surveillance is absent in most endemic countries leading to underestimation of the true burden of disease. This study aims to develop a uniform methodology to estimate the economic burden of Leptospirosis in the Latin American region to influence policy planning for better surveillance and control of the disease.
Methods: The overall economic burden in 14 endemic countries was estimated by monetizing DALYs using the willingness-to-pay (WTP) approach. This was compared to costs estimated by the cost-of-illness methodology, to compare the magnitude of the burden and highlight the strengths and limitations of each methodological approach.
Results: As per the WTP approach, the total economic burden in the region was estimated at 7.8 billion United States Dollar (USD) purchasing power parity (PPP). 42% of the cases were in Brazil causing a monetary impact of 128 million USD PPP. However, the cost-of-illness analysis estimated a burden of 49.5 million USD PPP, for the same period in Brazil.
Conclusions: The disease presents a huge burden in the Latin American region and demands policy action. The study highlights that the choice of methodology for the economic evaluation of disease burden greatly influences the final estimate obtained and the consequent conclusion derived. Hence, care should be taken while selecting the appropriate metric values, in the cost of illness studies, and the ones most suitable for the context of the disease should be used.
Background: Recent evidence have shown that individuals schedule appointments with primary care physicians for issues considered to be non-medical health needs, like loneliness. With the primary care system already overburdened by patients seeking a medical professional, a way to reduce these unnecessary visits is required. This proposed solution is Social Prescribing, a way to utilize community supports to meet these non-medical needs, improving health outcomes and reducing physician burden.
Methods: Currently being run by the Alliance for Healthier Communities, the project, RX: Community - Social Prescribing, is piloted in 11 Community Health Centres across Ontario. This is based on Social Prescribing in the UK and utilizes a health equity perspective. The pathway of Social Prescribing starts with a doctor identifying a patient who might benefit from the program. They are then referred to a Link Worker, who is familiar with community services and assess the client to see which programs would fit best. The client then attends the community support and has their non-medical need met. The evaluation is ongoing, however focus groups and interviews have been conducted with patients and primary care providers.
Results: In patients, common themes included improving their mental health, sense of community, and empowerment while decreasing social isolation, and loneliness. Physicians also saw the value of Social Prescribing and understood how it could help improve patient’s health. More data on patient health outcomes will be collected through Electronic Medical Records data comparing patients baseline and 1-year follow up after being a part of the program. Interviews with volunteers and staff identified that meetings and providing acknowledgement were key to the program’s success.
Conclusions: Social Prescribing has garnered media attention focusing on how it has impacted people’s lives. This project is the first to try and adapt Social Prescribing to various populations in Ontario: rural, urban, francophone, and indigenous. The pilot project captures how a health equity lens can be used for Social Prescribing to fit various community contexts and still be successful. When the pilot concludes, The Alliance hopes to scale the project up to more community health centres, and to other provinces.
Background: In Montréal, 86% of PWID living with HIV have been exposed to HCV. Assessing unmet needs in HCV prevention and treatment among key populations is critical to inform local elimination efforts. We aimed to estimate temporal trends in 1) HCV treatment initiation and efficacy, 2) injection practices, and 3) access to harm reduction among Montréal HIV-HCV co-infected PWID between 2003-2018.
Methods: We used data from the Canadian Co-infection Cohort, a prospective study of HIV-HCV co-infected individuals. Our analyses were restricted to Montréal participants who reported injection drug use between 2003-2018. We defined three time periods of interest based on HCV treatment guidelines: 2003-2010: interferon/ribavirin-based; 2011-2013: first-generation direct-acting antivirals (DAAs); 2014-2018: second-generation DAAs. We estimated HCV treatment initiation rates and efficacy (defined as the proportion reaching sustained virological response), and examined reported injection practices and access to harm reduction in the past six months (P6M). The harm reduction services assessed include needle and syringe programs (NSP), opioid agonist therapy (OAT), and supervised injection sites (SIS).
Results: We included 317 participants (80% male, median age 44 years at baseline). HCV treatment rate increased from 5/100 person-years (PY) (95% confidence interval (CI): 4-7) in 2003-2010, to 8/100 PY (95%CI: 5-12) in 2011-2013, and 31/100 PY (95%CI: 25-37) in 2014-2018, with treatment efficacy increasing from 50% to 80%. Report of needle/syringe sharing in the P6M reduced two-fold over time, and use of NSP decreased from 90% to 82%, whereas engagement in OAT increased from 2% to 4%. Recent opioid injection, however, increased over time (39%, 45%, and 52% in the three periods, respectively). SIS became available in 2014-2018 (reported at 3% of visits).
Conclusions: Recent increases in HCV treatment uptake could support elimination among HIV-HCV co-infected PWID, if sustained. However, harm reduction scale-up is needed to meet HCV elimination targets in Montreal.
Background: Depression is highly prevalent in the HIV-Hepatitis C (HCV) co-infected population. Even before a formal diagnosis, depressive symptoms can negatively impact outcomes. Due to competing health concerns, screening may not occur. We aimed to predict the presence of clinically significant depressive symptoms in the co-infected population using patient data with supervised machine learning.
Methods: We used sociodemographic, behavioural, and clinical predictors from the Canadian Co-infection Cohort (CCC), a multicentre prospective cohort and its associated sub-study on Food Security (FSS). The Center for Epidemiologic Studies Depression Scale-10 (CES-D-10) was administered in the FSS; scores >=10 indicate risk for major depression with clinically significant depressive symptoms. We developed two Random Forest classification algorithms to predict CES-D-10 class at each visit with 70% of the data using: I) all candidate predictors (x=137); and II) routinely available predictors (x=46). We evaluated the algorithms in the remaining 30% of the data using area under the curve (AUC), sensitivity and specificity, and identified important predictors.
Results: We included 1939 FSS visits from 718 participants, who were predominantly male (73%), white (76%), and unemployed (73%). At baseline, median age was 48 years (interquartile range (IQR), 43.3,53.9), median CES-D-10 score was 10 (IQR,5,15) and 53% with >=10 CES-D-10 score. Algorithm I performed better than algorithm II, with AUC of 0.84 (95%CI,0.80-0.87) and 0.76 (95%CI,0.72-0.80), respectively. The sensitivity and specificity were, I:Sens:0.74 (95%CI,0.68-0.79), Spec:0.79 (95%CI,0.74-0.84); II:Sens:0.74 (95%CI,0.69-0.79), Spec:0.69 (95%CI,0.63-0.74). Anxiety/depression dimension (EuroQoL-5D instrument), employment, age, education, revenue source, HIV clinical stage, and BMI were important predictors.
Conclusions: The classification algorithms yielded modest prediction accuracy and revealed important predictors for clinically significant depressive symptoms. However, prediction exhibited considerable misclassification despite machine learning using a rich set of variables. Therefore, routine screening using available tools remains warranted in the co-infected population rather than relying on prediction.
Background: This study aims to identify subtypes of attitudes among healthcare professionals regarding refugee claimants in Montreal and Toronto. Whether these subtypes vary in sociodemographic characteristics and whether they are associated with endorsing refugee claimant’s access to healthcare was investigated. It was hypothesized that there would be at least two subtypes of attitudes and that classes with more positive attitudes would be more likely to endorse refugee claimant access to healthcare.
Methods: Using data from an online survey administered to employees of healthcare institutions in Montreal and Toronto from the period 2014-2015, latent class analysis was used to identify the subtypes of healthcare professional attitudes. A final sample size of 4,066 participants were assigned into resulting subtypes and were used to conduct regression analysis to estimate the odds of endorsing equal access to health care for refugee claimants as a function of class membership.
Results: There were four subtypes (‘favorable’, ‘opposed,’ ‘unconcerned/status quo,’ and ‘ambivalent/reactive’) in terms of attitudes and opinions around access to healthcare for refugee claimants. Compared with those in the ‘opposed’ class, the odds of endorsing equal access to healthcare was 6.87 (95% CI 5.0-9.44) times higher among individuals in the ‘ambivalent/reactive’ class, 9.74 (95% CI 6.70, 14.19) times higher in the ‘unconcerned/status quo’ class and 72.50 (95% CI 52.87, 99.40) times higher in the ‘favorable’ class. Gender, age, occupation, and city were statistically significant covariates, with females less likely to endorse equal access than men (OR 0.83, 95% CI 0.70, 0.99). Overall endorsement of equal access to health care for refugee claimants in the entire sample was 52.32%.
Conclusions: Healthcare professionals’ attitudes regarding refugee claimants and ideas of deservingness of health can affect the delivery and access to care for refugee claimants. Results can be used to inform knowledge transfer strategies.
Background: In caring for patients within a hospital setting, healthcare workers’ hands are the primary source of transmission of hospital-acquired infections (HAI). Thus, practicing hand hygiene (HH) and adhering to HH guidelines are known to decrease the risk of HAIs. The objective of this study was to systematically review the published literature to determine optimal thresholds of healthcare workers’ HH compliance for preventing the acquisition or transmission of HAIs.
Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We searched four online databases using comprehensive search criteria for randomized controlled trials and non-randomized controlled studies investigating the impact of healthcare provider or healthcare worker HH compliance on HAI rates in patients of all ages within high-income hospital settings.
Results: Of the 6,646 articles, we excluded 6,354 articles in the title/abstract screening based on the following exclusion criteria: study conducted in low-middle-income country, secondary data, HH consumption and/or community HAI rates. A total of 292 full-texts articles were reviewed and 36 articles met the inclusion criteria. All 36 studies reported compliance and HAI rates as cross-sectional measures rather than longitudinal and were not designed to measure causality of HH compliance and HAI rates
Conclusions: Although HH compliance is part of healthcare worker’s code of conduct, there is limited motivation to adhere to current HH guidelines. Therefore, there is a need for high-quality evidence to support implementation of HH and determine if a causal relationship exists between HH compliance and HAI rates.
Background: Sri Lanka has achieved remarkable improvements in healthcare during the past few decades. The country offers free health care and has reduced maternal, infant and child mortality to levels similar to those of high-income countries. Sri Lanka’s Family Health Bureau (FHB) is the leading organization that develops public health policies on a national level. The FHB’s Reproductive, Maternal, Neonatal, Child, Adolescent and Youth Health (RMNCAYH) program is the most important contributing factor for the quality of maternal and child health (MCH) services available in the country.
Methods: Using software developed by the FHB called the electronic Reproductive Health Management Information System (eRHMIS), the Monitoring and Evaluation unit looks into the data reported at the community level by medical officers, public health midwives and public health inspectors. MCH reviews are held in each district to discuss problems of data reporting, data quality and emerging health trends in each area. Issues identified at each review are reported to respective units of the RMNCAYH program and later included in the FHB’s annual report. They are also notified to the Minister of Health and to partners such as the World Health Organization and United Nations Development Program. Nine district reviews were held during the months of May to August 2019. The districts were part of the Southern, North Eastern, Central and Western provinces of the country.
Results: Recurring issues identified were the lack of reporting of gender-based violence, increasing Lower Segment Caesarian Section rates, poor quality of data reporting on low birth weight outcome and inadequacy of folic acid intake among women.
Conclusions: Evidence-based approaches to addressing each issue were researched and reported to the national program manager of the RMNCAYH programs. However, Sri Lanka will require well-funded, more focused and targeted interventions to address these emerging public health concerns.