Burden Of Disease In Canada Research Articles

2023 Update On the Screening and Treatment of Localized Prostate Cancer

Prostate cancer represents a major burden of disease in Canada. It represents the third leading cause of cancer mortality in men with more than 24,000 individuals diagnosed in 2021. The diagnosis and management of prostate cancer is a continuously evolving area, and the aim of this article is to provide current information on various aspects of prostate cancer care, as an aid for primary care physicians (PCPs) as they guide men through the prostate cancer journey.

Modelling population-level and targeted interventions of weight loss on chronic disease prevention in the Canadian population

Obesity is a known risk factor for major chronic diseases. Prevention of chronic disease is a top global priority. The study aimed to model scenarios of population-level and targeted weight loss interventions on 10-year projected risk of chronic disease in Canada using a population-level risk prediction algorithm. The validated Chronic Disease Population Risk Tool (CDPoRT) forecasts 10-year risk of chronic disease in the adult population. We applied CDPoRT to the 2013/14 Canadian Community Health Survey to generate prospective chronic disease estimates for adults 20 years and older in Canada (n = 83,220). CDPoRT was used to model the following scenarios: British Columbia's (BC) and Quebec's (QC) provincial population-level weight reduction targets, a population-level intervention that could achieve weight loss, targeted weight loss interventions for overweight and obese groups, and the combination of a population-level and targeted weight loss intervention. We estimated chronic disease risk reductions and number of cases prevented in each scenario compared with the baseline. At baseline, we predicted an 18.4% risk and 4,151,929 new cases of chronic disease in Canada over the 10-year period. Provincial weight loss targets applied to the Canadian population estimated chronic disease reductions of 0.6% (BC) and 0.1% (QC). The population-level intervention estimated a greater reduction in risk (0.2%), compared to the targeted interventions (0.1%). The combined approach estimated a 0.3% reduction in chronic disease risk. Our modelling predicted that population-level approaches that achieve weight loss in combination with targeted weight loss interventions can substantially decrease the chronic disease burden in Canada.

The importance of sex and age disaggregated data.

The importance of sex and age disaggregated data.

A Call to Action: Optimizing Indigenous Cardiovascular Health in Canada.

Indigenous peoples in Canada continue to experience substantially higher rates of cardiovascular disease compared to non-Indigenous Canadians. Herein, we 1) identify upstream factors contributing to the current state of Indigenous cardiovascular health, 2) suggest culturally responsive approaches to engage Indigenous patients and communities, and 3) propose strategies to enhance collaborative, culturally safe research and healthcare access in Indigenous communities in Canada.

Exposure to Endocrine Disrupting Chemicals in Canada: Population-Based Estimates of Disease Burden and Economic Costs

Exposure to endocrine-disrupting chemicals (EDCs) contributes to substantial disease burden worldwide. We aim to quantify the disease burden and costs of EDC exposure in Canada and to compare these results with previously published findings in the European Union (EU) and United States (US). EDC biomonitoring data from the Canadian Health Measures Survey (2007–2011) was applied to 15 exposure–response relationships, and population and cost estimates were based on the 2010 general Canadian population. EDC exposure in Canada (CAD 24.6 billion) resulted in substantially lower costs than the US (USD 340 billion) and EU (USD 217 billion). Nonetheless, our findings suggest that EDC exposure contributes to substantial and costly disease burden in Canada, amounting to 1.25% of the annual Canadian gross domestic product. As in the US, exposure to polybrominated diphenyl ethers was the greatest contributor of costs (8.8 billion for 374,395 lost IQ points and 2.6 billion for 1610 cases of intellectual disability). In the EU, organophosphate pesticides were the largest contributor to costs (USD 121 billion). While the burden of EDC exposure is greater in the US and EU, there remains a similar need for stronger EDC regulatory action in Canada beyond the current framework of the Canadian Environmental Protection Act of 1999.

Consensus-Based Development of an Assessment Tool: A Methodology for Patient Engagement in Primary Care and CPD Research.

With cardiovascular disease (CVD) posing a significant disease burden in Canada and more broadly, preventative efforts which incorporate best evidence, patient preference, and physician expertise must continue to take place. Primary care providers play a pivotal role in this effort, and a greater understanding of patient perspectives is needed to guide management and inform training. We used a validated consensus method, the nominal group technique (NGT), to identify patient-reported experience measures (PREM) related to CVD prevention deemed most important by both patients and providers. The NGT was used by using structured discussions between patients and providers to bring ideas about PREM CVD outcomes to a consensus. Four patient partners and four primary care providers were selected to participate in an NGT session. Each participant wrote down items/questions they believed important in CVD preventative care. After discussions, all items underwent anonymous ranking on a 5-point scale. Items were included/excluded based on 75% agreement a priori. The panel produced 10 items from a total of 26 after 2 rounds of ranking. The top two items were as follows: “Is your treatment plan tailored to you” and “Was your physician good at giving information about your risk factors?” These results are significantly different compared with existing quality measures because they highlight aspects of patient experience and therapeutic relationship. A questionnaire consisting of prioritized PREM items is valuable in quality improvement and continuous professional development (CPD).

Invasive bacterial diseases in northern Canada, 1999 to 2018

Background: The International Circumpolar Surveillance (ICS) program conducts surveillance on five invasive bacterial diseases: pneumococcal disease (IPD), group A streptococcus (iGAS), Haemophilus influenzae (Hi), meningococcal disease (IMD) and group B streptococcus (GBS). Invasive bacterial diseases have a higher burden of disease in northern populations than the rest of Canada. Methods: To describe the epidemiology of invasive bacterial diseases in northern Canada from 1999 to 2018, data for IPD, iGAS, Hi, IMD and GBS were extracted from the ICS program and the Canadian Notifiable Diseases Surveillance System (CNDSS) and analyzed. Results: The annualized incidence rates for IPD, iGAS, Hi, GBS and IMD were 23.3, 10.5, 8.9, 1.9 and 1.1 per 100,000 population, respectively. The incidence of IPD, iGAS and Hi serotype b were 2.8, 3.2 and 8.8 times higher, respectively, in northern Canada than in the rest of Canada. Rates of disease decreased statistically significantly for IPD (β=−0.02) and increased statistically for iGAS (β=0.08) and Hi serotype a (β=0.04) during the study period. In Northern Canada, the annualized incidence rates for IPD, iGAS and Hi were statistically higher for Indigenous residents than for non-Indigenous residents. The highest incidence rates were among the very young and older age groups. Conclusion: Invasive bacterial diseases represent a high burden of disease in Canada’s northern populations. Indigenous peoples, children and seniors are particularly at risk.

HOMOZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA IN CANADA

<h3>BACKGROUND</h3> Homozygous familial hypercholesterolemia (HoFH) is an orphan disease characterized by extremely high levels of plasma levels of LDL-C. Affected patients develop clinical atherosclerotic cardiovascular disease (ASCVD) in youth and survival > 30 years of age was unusual until the advent of medications (statins) and extracorporeal LDL filtration (apheresis) techniques. HoFH is an autosomal co-dominant condition defined as an LDL-C > 13 mmol/L in adults without treatment and homozygous or compound heterozygous mutations of the LDLR gene. HoFH has a genetic probability of ∼1/386,000 and the rare diseases inventory Orphanet estimates its worldwide prevalence at 1/1,000,000 individuals. Canada is known to have several regions with a founder effect for HoFH and we identified 79 cases across the country. Data from other countries show a median survival of HoFH patients at <40 years of age. Clinical outcomes in HoFH patients, especially ASCVD events (fatal and non-fatal myocardial infarctions, strokes and peripheral vascular disease) and severe calcific aortic stenosis, are difficult to capture, in part because of the rarity of the disorder and the lack of registry focusing on this disease. The objective of our project is to obtain a comprehensive registry of HoFH in Canada, estimate the cost to society caused by HoFH burden of disease in Canada, and implement changes to advocate access to specialized care for these patients. <h3>METHODS AND RESULTS</h3> Here, we present preliminary data (Table 1) on our Canadian HoFH registry, including medical history, levels of LDL-C, treatments and outcomes of 21 HoFH patients. <h3>CONCLUSION</h3> We plan to use this data at provincial and national levels, in help with the Canadian Organization for Rare Diseases (CORD) and the Réseau Québecois des maladies orphelines (RQMO), to provide HoFH patients access to care, including PCSK9 inhibitors, orphan drugs such as lomitapide and evinacumab, and treatment techniques such as extracorporeal LDL filtration (apheresis). This work will provide important new health-related knowledge about the determinants of ASCVD risk and phenotypic manifestations of HoFH in Canada and examine the quality of life and burden to the healthcare system.

Need for universal hepatitis C screening in incarcerated populations

Hepatitis C carries a large burden of disease in Canada. Barriers to care, especially in the incarcerated population, may impede effective treatment and the achievement of targets for disease eradication. Access to universal screening in incarcerated populations could support engagement in the care cascade, and local studies around prevalence and screening efficacy could be used to justify and inform screening programs. A focus on incarcerated populations is an important step toward HCV eradication and ensuring equitable healthcare for all. This article will discuss the HCV care cascade, the unique burden of HCV in correctional facilities, and provide an argument in support of universal screening in incarcerated populations.

The Alcohol-Attributable Burden of Disease in Canada from 2000 to 2016

ABSTRACT Objectives: To describe trends in Canada in alcohol consumption from 1990 to 2016, and in the alcohol-attributable burden of disease from 2000 to 2016. Methods: Alcohol consumption was measured using data from production and taxation statistics and from population surveys. Alcohol-attributable deaths and disability adjusted life years (DALYs) lost were estimated using a comparative risk assessment framework, stratified by age, sex, and cause. Relative risks were obtained from meta-analyses and cohort studies. Mortality data were obtained from the World Health Organization's Global Health Observatory. Uncertainty intervals (UIs) were estimated using Monte Carlo-like simulations. Results: From 1990 to 2016, per capita alcohol consumption in Canada decreased from 10.4L (95% UI: 10.0–10.7) to 9.0L (95% UI: 8.7–9.2). Heavy episodic drinking remained largely stable between 1990 and 2016 (an annualized 0.1% increase). In 2016, 10,556 deaths (95% UI: 8285–13,609) and 440,709 DALYs lost (95% UI: 388,853–527,260) were attributable to alcohol use. Men experienced more alcohol-attributable deaths and DALYs lost than did women, and the greatest alcohol-attributable burden was found among those over the age of 54. Alcohol-attributable age-standardized rates of deaths and DALYs lost decreased by 18.7% (95% UI: −10.2 to 25.2) and by 13.8% (95% UI: –11.4, 15.7), respectively, from 2000 to 2016. Conclusions: Despite reductions in per capita consumption and in the alcohol-attributable burden of disease, alcohol use continues to be a leading risk factor for death and disability in Canada. Accordingly, alcohol control policies should be strengthened to reduce further alcohol-attributable harms. Objectifs: Décrire les tendances de la consommation d’alcool au Canada de 1990 à 2016 et du fardeau de la maladie attribuable à l’alcool de 2000 à 2016. Méthodes: La consommation d’alcool a été mesurée à l’aide de données provenant de statistiques de production et de taxation et données d’enquêtes sur la population. Alcohol-attributable deaths and disability adjusted life years (DALYs) - les années de vie ajustées par les décès et les cas d’invalidités attribuables à l’alcool- perdues ont été estimés à l’aide d’un cadre d’évaluation comparatif des risques, et stratifié par âge, sexe et cause. Les risques relatifs ont été obtenus à partir de méta-analyses et d’études de cohorte. Les données sur la mortalité ont été obtenues auprès de l’Observatoire mondial de l’Organisation mondiale de la santé. Les intervalles d’incertitude (UI) ont été estimés à l’aide de simulations de type Monte Carlo. Résultats: De 1990 à 2016, la consommation d’alcool per capita au Canada est passée de 10,4 L (95% UI: 10.0, 10.7) à 9,0 L (95% UI: 8.7, 9.2). La consommation épisodique excessive est restée largement stable entre 1990 et 2016 (une augmentation annualisée de 0.1%). En 2016, 10 556 décès (95% UI: 8 285, 13 609) et 440 709 DALYs perdus (95% UI: 388 853, 527 260) étaient attribuables à la consommation d’alcool. Les hommes ont connu plus de décès et de DALYs perdus attribuables à l’alcool que les femmes, et le fardeau le plus lourd attribuable à l’alcool a été constaté chez les personnes de plus de 54 ans. Les taux de décès normalisés selon l’âge attribuables à l’alcool et de DALYs perdus ont diminué de 18,7% (95%UI: -10.2, 25.2) et de 13,8% (95% UI: -11.4, 15.7), respectivement, de 2000 à 2016. Conclusions: Malgré les réductions de la consommation per capita et du fardeau de la maladie attribuable à l’alcool, la consommation d’alcool continue d’être l’un des principaux facteurs de risque de décès et d’incapacité au Canada. En conséquence, les politiques de contrôle de l’alcool devraient être renforcées afin de réduire davantage les méfaits attribuables à l’alcool.

PMS78 CANADIAN REAL-WORLD EVIDENCE ON EPIDEMIOLOGY, OUTCOMES AND ECONOMICS OF MODERATE-TO-SEVERE OSTEOARTHRITIS: A SYSTEMATIC LITERATURE REVIEW

The Public Health Agency of Canada reports ∼3.6M Canadians (2010 population: 33.7M), are living with any type of osteoarthritis (OA). Quality of life is greatly impacted among patients with moderate-to-severe OA; therefore, capturing the burden of disease in Canada is important for planning novel treatment strategies. To identify real-world evidence (RWE) on the clinical and economic burden of moderate-to-severe OA in Canada via systematic literature review. Search strategies were executed in MEDLINE, Embase, the Cochrane Library, and selected conferences to identify citations published between Jan 2013 and Nov 2018. Selection criteria included Canadian populations with clinically or radiologically confirmed moderate-to-severe OA, defined by author. Outcomes included: prevalence, clinical or economic measures and treatments. This review was conducted and reported in-line with the PRISMA statement. 1881 citations were screened and 19 Canadian RWE studies were included. Prevalence rates were not reported. One microsimulation model estimated that 649K Canadians visited an orthopaedic surgeon for total joint replacement evaluation/surgery. Study populations were predominately female (44-83%) and 57-74 years old. Only 7 studies captured joint characteristics of individuals with moderate-to-severe OA of the hip or knee; only 6 studies reported pain scores. The main findings included an average of 3-6 symptomatic joints (3 studies); hypertension as the most common comorbidity (61-68%; 2 studies), and NSAIDs as the most frequent treatment (2 studies). Opioid use was not consistently reported (3 studies). The estimated average annual cost of OA per person increased with disease severity ($468 to $3,185; 2017 $CAD), with the highest costs for moderate-to-severe, driven by joint replacement. Burden of moderate-to-severe OA in Canada is significant; however, inequities in recent/standardized definitions and reporting highlight an important gap in prevention and treatment strategies. Despite limited data, progressing disease and worsening disability leads to poor patient-outcomes and increased healthcare costs.

The impact of pharmaceutical innovation on the burden of disease in Canada, 2000-2016.

We perform an econometric assessment of the role that pharmaceutical innovation—the introduction and use of new drugs—has played in reducing the burden of disease in Canada, by investigating whether diseases for which more new drugs were launched had larger subsequent reductions in disease burden. Since utilization of a drug reaches a peak about 12–14 years after it was launched, we allow for considerable lags in the relationship between new drug launches and the burden of disease.We analyze the impact of new drug launches on a comprehensive measure of disease burden—the age-standardized disability-adjusted life-years lost (DALY) rate—and on its two components: the age-standardized years of life lost (YLL) and years lost to disability (YLD) rates. We also analyze the impact of new drug launches on the number of hospital discharges and on the average length of hospital stays.The number of DALYs lost is significantly inversely related to the number of drugs that had ever been launched 9–20 years earlier, and the number of YLLs is significantly inversely related to the number of drugs that had ever been launched 11–20 years earlier. The launch of a drug has the largest (most negative) impact on the number of DALYs and YLLs 15 years after it was launched.The estimates indicate that if no drugs had been launched during 1986–2001, the age-standardized DALY rate would not have declined between 2000 and 2016; it might even have increased. Almost all (93%) of the reduction in DALYs was due to a reduction in YLL. The estimates imply that new drug launches during 1986–2001 reduced DALYs in 2016 by 21%, reduced YLLs in 2016 by 28%, and reduced YLDs in 2016 by 3%.We estimate that drugs launched during 1986–2001 reduced the number of DALYs lost in 2016 by 2.31 million. Expenditure in 2016 on drugs launched during 1986–2001 per DALY gained in 2016 from those drugs was 2842 USD. Interventions that avert one DALY for less than average per capita income for a given country or region are generally considered to be very cost–effective; Canada's per capita GDP was 42,158 USD in 2016, so our estimates indicate that the new drugs launched during 1986–2001 were very cost–effective, overall.Moreover, 2842 USD may be an overestimate of the true net cost in 2016 per DALY of drugs launched during 1986–2001. A previous study based on U.S. data showed that about 25% of the cost of new drugs is offset by reduced expenditure on old drugs. Also, our estimates indicate that, if no drugs had been launched during 1986–2001, the average length of 2016 hospital stays would have been about 16% higher. The reduction in hospital expenditure due to shorter average length of stay may have been larger than the expenditure on the drugs responsible for shorter hospital stays.

Effect of predicted travel time to trauma care on mortality in major trauma patients in Nova Scotia

Trauma is a leading contributor to the burden of disease in Canada, accounting for more than 15 000 deaths annually. Although caring for injured patients at designated trauma centres (TCs) is consistently associated with survival benefits, it is unclear how travel time to definitive care influences outcomes. Using a population-based sample of trauma patients, we studied the association between predicted travel time (PTT) to TCs and mortality for patients assigned to ground transport. Victims of penetrating trauma or motor vehicle collisions (MVCs) in Nova Scotia between 2005 and 2014 were identified from a provincial trauma registry. We conducted cost distance analyses to quantify PTT for each injury location to the nearest TC. Adjusted associations between TC access and injury-related mortality were then estimated using logistic regression. Greater than 30 minutes of PTT to a TC was associated with a 66% increased risk of death for MVC victims (p = 0.045). This association was lost when scene deaths were excluded from the analysis. Sustaining a penetrating trauma greater than 30 minutes from a TC was associated with a 3.4-fold increase in risk of death. Following the exclusion of scene deaths, this association remained and approached significance (odds ratio 3.48, 95% confidence interval 0.98–14.5, p = 0.053). Predicted travel times greater than 30 minutes were associated with worse outcomes for victims of MVCs and penetrating injuries. Improving communication across the trauma system and reducing prehospital times may help optimize outcomes for rural trauma patients.

Impact of availability of direct-acting antivirals for hepatitis C on Canadian hospitalization rates, 2012-2016.

Hospitalizations associated with hepatitis C virus (HCV) infection and liver disease increased on average by 6.0% per year from 2004 to 2010 in Canada and were projected (in 2010) to increase by another 4% by 2016. The first generation of direct-acting antivirals (DAAs) became available in 2012. In 2014, a second generation of effective and well-tolerated DAA therapy was authorized in Canada. The impact of DAA therapy on the HCV-associated disease burden in Canada has not been documented. To assess the potential impact of DAA therapy on the disease burden by a) comparing the actual hospitalization rates associated with HCV infection and liver disease following the introduction of DAAs in Canada with the 2010 baseline projection and b) documenting the associated uptake of anti-HCV therapy. The hospital records of inpatients diagnosed with chronic HCV and chronic liver disease were extracted from the Canadian Discharge Abstract Database (DAD) by fiscal year for 2004-2016. We compared the actual number of hospitalizations to the baseline projection by year and for selected 5-year birth cohorts (1925-1989). The monthly number of new prescriptions for anti-HCV regimens was extracted from the IQVIA CDH CompuScript database (formerly IMS Health), aggregated to annual levels by age group and compared with hospitalization trends. Compared to the baseline projection, there was a slight reduction in hospitalizations in 2014/15 and 2015/16. This slight reduction was followed by a more significant decline in 2016/17 (32% below expected; 95% confidence interval [CI]: 27%-37%). The largest declines were observed for patients born before 1960 (age 55 or older) at 40% below expected in 2016/17. The number of new anti-HCV prescriptions increased from 5,484 in fiscal year 2012/13 to a peak of 17,775 in 2015/2016. The number of new prescriptions corresponds to approximately 1.3 and five times the number of hospitalizations in 2012/13 and 2015/16, respectively. In Canada there has been a modest decrease in HCV and liver-related hospitalizations following a significant increase in uptake of second-generation DAAs in 2015. However, the burden is still high. Linked health administrative databases created to monitor the disease burden in the new treatment era should provide additional insight with the linkage of treatment history and disease stage to individual outcomes.

Summary of the NACI Update on Immunization in Pregnancy with Tetanus Toxoid, Reduced Diphtheria Toxoid and Reduced Acellular Pertussis (Tdap) Vaccine.

In Canada, pertussis is an endemic and cyclical disease, with peaks occurring at two- to five-year intervals. Although pertussis incidence varies by age group, unvaccinated or undervaccinated infants are at greatest risk of infection and associated complications. Since the last National Advisory Committee on Immunization (NACI) recommendations published in 2014, new evidence on the safety and effectiveness of tetanus toxoid, reduced diphtheria toxoid and reduced acellular pertussis (Tdap) vaccine administration in pregnancy has become available. To provide guidance on maternal immunization in pregnancy as a strategy to reduce disease incidence and severe outcomes (defined as hospitalization or death) from pertussis infection in infants less than 12 months of age. The NACI reviewed evidence on the burden of disease in Canada, vaccine safety and immunogenicity and vaccine effectiveness in jurisdictions that have implemented maternal immunization programs. A total of 59 articles were identified, retrieved and included in the literature review to inform this statement. In the majority of reviewed studies, post immunization increases in antibody levels resulted in more than 90% of women achieving anti-PT levels greater than or equal to 10 IU/ml one month following immunization. In infants, maternal immunization was found to result in increased pertussis antibody concentrations. In the majority of studies, following the receipt of the fourth diphtheria, tetanus and pertussis (DTaP) dose after 15 months of age, no statistically significant differences in antibody levels and avidity were observed between infants whose mothers received Tdap in pregnancy and those whose mothers did not receive Tdap in pregnancy. No major maternal or infant safety issues, including pregnancy outcomes, were reported in the reviewed literature. Effectiveness of maternal Tdap immunization in pregnancy was estimated to be over 90% against pertussis in infants younger than two months of age, with no deaths observed among infants whose mothers received Tdap prior to 36 weeks of pregnancy. Maternal immunization with Tdap in pregnancy also resulted in a reduction in infant disease severity and hospitalization. Vaccine effectiveness was also reported to persist after the receipt of the first three DTaP doses, with immunization in pregnancy resulting in additional protection of up to 70% in children whose mothers received Tdap in pregnancy. There is now strong evidence to support the NACI recommendation that immunization with Tdap vaccine should be offered in every pregnancy. This is ideally administered between 27 and 32 weeks of gestation but evidence also supports providing maternal Tdap over a wider range of gestational ages, from 13 weeks up to the time of delivery, in view of programmatic and unique patient considerations.

Trends in Gout and Rheumatoid Arthritis Hospitalizations in Canada From 2000 to 2011.

Gout and rheumatoid arthritis (RA) are the 2 most common forms of inflammatory arthritis worldwide. As hospitalizations for both conditions lead to substantial health resource use, contemporary inpatient trends and associated costs may provide important benchmarks of disease burden. However, relevant data are limited. We used PopulationData BC, a population-based administrative data set from Canada. We examined trends in the annual hospitalization and surgery rate of gout and RA from 2000 to 2011. Additionally, we examined annual trends in the inpatient cost burden of both conditions. We assessed annual trends in hospitalization and surgery rates using Poisson regression models and cost trends using linear regression models. From 2000 to 2011, the annual hospitalization rate for RA declined by 49% from 15.4 to 7.9 per 100,000 Canadian adults (P < 0.001), whereas that for gout doubled from 3.8 to 7.6 per 100,000 Canadian adults (P < 0.001). Approximately 31% of RA admissions were associated with hip or knee replacement surgery; the trend of these surgeries paralleled the declining trend in RA hospitalizations (P = 0.0097). The inpatient costs also reflected the hospitalization trends, with a 40% decrease in RA hospital costs, while gout costs more than doubled over the study period. Our findings indicate that hospitalization rates for gout have doubled over the past decade, while those for RA have decreased considerably. While these data provide an encouraging benchmark for RA care, they also highlight the critical need to improve gout management and prevention to mitigate its rising disease burden in Canada and beyond.

A systematic review of risk factors associated with muscular dystrophies

The purpose of this study was to systematically review, assess, and prioritize factors (including biological, socioeconomic, environmental, psychosocial, comorbid, and genetic) for the onset and natural progression of Muscular Dystrophy. Comprehensive review of current literature of these factors was carried out in order to provide a basis for policy makers to identify appropriate measures to mitigate the burden of disease in Canada. A three-stage approach to searching for relevant studies was conducted in multiple databases. Using variations of MeSH terms and keywords, Systematic reviews or meta-analyses published in English or French that meet the inclusion criteria were first identified, then searched for relevant observational studies. Two independent reviewers screened abstracts, then qualifying articles, conducted quality assessment, and finally extracted relevant data using the application, DistillerSR. No existing systematic reviews, meta-analyses, or non-genetic observational studies were identified that met the inclusion criteria. A number of existing systematic reviews and observational studies focused on pharmacological or therapeutic interventions, which was beyond the scope of this study. Four genetic observational studies were identified that focused on aspects of disease progression of Duchenne and Becker Muscular Dystrophy. While this systematic review found that certain genetic polymorphisms and mutations may be a factor for Duchenne or Becker Muscular Dystrophy disease progression, further investigation into other genetic factors and environmental factors is still warranted. Much of the current literature focuses on these Muscular Dystrophies, however, other types of Muscular Dystrophy and their associated risk factors have yet to be extensively studied.

A systematic review of the risks factors associated with the onset and natural progression of spina bifida

The purpose of this study was to systematically assess and synthesize the world literature on risk factors for the onset and natural progression of spina bifida, thereby providing a basis for policy makers to identify appropriate risk management measures to mitigate the burden of disease in Canada. Searches of several health literature databases from inception to February 2013 were conducted by a health sciences librarian. A total of three meta-analyses that studied a risk factor for the onset of spina bifida were included. Pooled results showed that paternal exposure to Agent Orange (RR=2.02; 95% CI 1.48–2.74) and maternal obesity prior to pregnancy (OR=2.24; 95% CI 1.86–2.74) each increased the risk of having a child with spina bifida. Paternal exposure to organic solvents was also close to the limit of significance (OR=1.59; 95% CI 0.99–2.56). A total of 63 observational studies, encompassing hundreds of potential risk factors, were included for risk factors for the onset of disease. One meta-analysis and four observational studies examined the impact of genetic risk factors. Only specified mutations in the 5,10-methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) genes were found to be linked to disease onset. One observational study evaluated a risk factor for the natural progression of disease. An extensive number of potential risk factors for the onset of spina bifida have been studied, though most lack sufficient evidence to confirm an association. Currently, strong evidence exists to suggest a causal association for maternal obesity prior to pregnancy, and paternal exposure to Agent Orange.

A systematic review of the risks factors associated with the onset and natural progression of hydrocephalus

The purpose of this study was to systematically assess and synthesize the world literature on risk factors for the onset and natural progression of hydrocephalus, thereby providing a basis for policy makers to identify appropriate risk management measures to mitigate the burden of disease in Canada. Evidence for risk factors was limited for both onset and progression. Two meta-analyses that examined a risk factor for onset met the inclusion criteria. One found a significant protective effect of prenatal vitamins among case control studies, but not cohort/randomized controlled trials (RCTs). The second found maternal obesity to be a significant risk factor for congenital hydrocephalus. Significant risk factors among 25 observational studies included: biological (multiple births, maternal parity, common cold with fever, maternal thyroid disease, family history, preterm birth, hypertension, ischemic heart disease, ischemic ECG changes, higher cerebrospinal fluid protein concentration following vestibular schwannoma); lifestyle (maternal obesity, high-density lipoprotein (HDL) cholesterol, maternal diabetes, maternal age), healthcare-related (caesarean section, interhospital transfer, drainage duration following subarachnoid hemorrhage, proximity to midline for craniectomy following traumatic brain injury); pharmaceutical (prenatal exposure to: tribenoside, metronidazole, anesthesia, opioids); and environmental (altitude, paternal occupation). Three studies reported on genetic risk factors: no significant associations were found. There are major gaps in the literature with respect to risk factors for the natural progression of hydrocephalus. Only two observational studies were included and three factors reported. Many risk factors for the onset of hydrocephalus have been studied; for most, evidence remains limited or inconclusive. More work is needed to confirm any causal associations and better inform policy.

Major Depression in Canada: What Has Changed over the Past 10 Years?

Major depressive episodes (MDE) make an important contribution to disease burden in Canada. The epidemiology of MDE in the national population has been examined in 2 mental health surveys, one conducted in 2002 and the other in 2012. Our objective was to compare selected variables from the 2 surveys to determine whether changes have occurred in the prevalence, treatment, and impact of MDE. The World Health Organization World Mental Health Composite International Diagnostic Interview was used in both surveys and the MDE module (which was not modified) was scored using the same algorithm. Some variables assessing impact and management of MDE were also identical in the 2 surveys. The analysis was based on frequency estimates and associated 95% confidence intervals. The annual prevalence of MDE was 4.7% (95% CI 4.3% to 5.1%) in 2012, nearly identical to 4.8% (95% CI 4.5% to 5.1%) in 2002. Receipt of potentially adequate treatment (defined as taking an antidepressant or 6 or more visits to a health professional for mental health reasons) increased from 41.3% in 2002 to 52.2% in 2012, mostly due to an increase in respondents reporting 6 or more visits. Use of second generation antipsychotics also increased. There was no evidence of diminishing prevalence or impact (as assessed by symptoms of distress). There appears to have been an increase in receipt of treatment for people with MDE and a changing pattern of management. However, it was not possible to confirm that the impact of MDE is diminishing as a result.