Canadian Population-based Study Research Articles

Use of Preoperative Magnetic Resonance Imaging for Breast Cancer: A Canadian Population-Based Study.

Contrary to practice guidelines, breast magnetic resonance imaging (MRI) is commonly used in the preoperative evaluation of women with breast cancer. While existing literature has found little benefit to MRI in most patients, potential downstream consequences associated with breast MRI are not well described. To describe patterns of preoperative breast MRI utilization in a health care system with universal insurance and its association with downstream investigations and clinical outcomes. This was a population-based retrospective cohort study using administrative heath care databases in Ontario, Canada (2012 population, 13.5 million) over 14 geographic regions were evaluated within the data set. Participants comprised 53 015 patients with primary operable breast cancer treated from 2003 to 2012. Use of preoperative breast MRI by year, geographic region, and breast cancer stage. Postdiagnosis imaging, biopsy, and short-term surgical outcomes were also evaluated between those who did and did not receive MRI. Overall, 14.8% of patients (7824 of 53 015) had a preoperative MRI. During the 10-year study period, MRI use increased across all stages by 8-fold (from 3% to 24%; P < .001 for trend). Factors associated with MRI use were younger age, higher socioeconomic status, higher Charlson comorbidity score, surgery performed in a teaching hospital, and fewer years of surgeon experience. Multivariate analyses showed that preoperative breast MRI was associated with higher likelihood of the following: postdiagnosis breast imaging (odds ratio [OR], 2.09; 95% CI, 1.92-2.28), postdiagnosis breast biopsies (OR, 1.74; 95% CI, 1.57-1.93), postdiagnosis imaging to assess for distant metastatic disease (OR, 1.51; 95% CI, 1.42-1.61), mastectomy (OR, 1.73; 95% CI, 1.62-1.85), contralateral prophylactic mastectomy (OR, 1.48; 95% CI, 1.23-1.77), and a greater than 30-day wait to surgery (OR, 2.52; 95% CI, 2.36-2.70) (all ORs are adjusted). Preoperative breast MRI use has increased substantially in routine clinical practice and is associated with a significant increase in ancillary investigations, wait time to surgery, mastectomies, and contralateral prophylactic mastectomies.

Health risk of air pollution on people living with major chronic diseases: a Canadian population-based study

ObjectivesThe objective of this study was to use health administrative and environmental data to quantify the effects of ambient air pollution on health service use among those with chronic diseases....

Examining palliative care program use and place of death in rural and urban contexts: a Canadian population-based study using linked data

Palliative care has been both more available and more heavily researched in urban than in rural areas. This research studies factors associated with palliative care program (PCP) enrollment and place of death across the urban/rural continuum. Importantly, rather than simply comparing urban and rural areas, this article examines how the effects of demographic, geographic, and socioeconomic factors differ across service delivery settings within the Canadian province of Nova Scotia. This study linked PCP patient enrollment files from three districts to Nova Scotia vital statistics death certificate data. Postal codes of the decedents were mapped to 2006 Canadian dissemination area census data. The study examined 23 860 adult residents of three district health authorities, who died from 2003 to 2009 with a terminal illness, organ failure, or frailty and who were not nursing home residents. Demographic, geographic, and socioeconomic predictors of PCP enrollment and place of death were investigated using logistic regression across the entire study area, and stratified by district of residence. Univariate and multivariate (adjusted) odds ratios (OR) and their 95% confidence intervals (CI) are reported. Overall, 40.3% of the study subjects were enrolled in a PCP, and 73.4% died in hospital. Odds of PCP enrollment were highest for females (OR: 1.30; 95%CI: 1.22, 1.39), persons aged 50-64 years (OR: 1.50; 95%CI: 1.35, 1.67), and persons with a terminal disease such as cancer. While in overall multivariate analysis residents of census metropolitan areas and agglomerations had higher odds of enrollment (OR: 1.51; 95%CI: 1.29, 1.77), and those at greater distance from a PCP had lower odds (OR: 0.33; 95%CI: 0.27, 0.40), stratified analysis revealed a more nuanced picture. Within each district, travel time to PCP remained a significant predictor of enrollment but the magnitude of its effect differed markedly. There was no consistent relationship with urban/rural residence, social deprivation, or economic deprivation. Enrollment in a PCP was associated with lower adjusted odds of dying in hospital (OR: 0.78; 95%CI: 0.72, 0.84), and those living at greater distance from a PCP had higher odds of hospitalization (OR: 1.52; 95%CI: 1.28, 1.81), but there was no consistent relationship for urban/rural residence or across districts. Geographic patterns of PCP enrollment and place of death differed by district, as did the impact of economic and social deprivation. Analysis and reporting of population-based indicators of access should be grounded in an understanding of the characteristics of geographic areas and local context of health services. Although more research is needed, these findings show promise that disparities in access between urban and rural settings are not unavoidable, and positive aspects of rural and remote communities may be leveraged to improve care at end of life.

Su1310 Pregnancy and Birth Rates Are Decreased Among Women With IBD: Results of a Canadian Population-Based Cohort Study

Su1310 Pregnancy and Birth Rates Are Decreased Among Women With IBD: Results of a Canadian Population-Based Cohort Study

Dietary patterns and colorectal cancer: results from a Canadian population-based study

BackgroundThe relationship between major dietary patterns and colorectal cancer (CRC) in other populations largely remains consistent across studies. The objective of the present study is to assess if dietary patterns are associated with the risk of CRC in the population of Newfoundland and Labrador (NL).MethodsData from a population based case–control study in the province of NL were analyzed, including 506 CRC patients (306 men and 200 women) and 673 controls (400 men and 273 women), aged 20–74 years. Dietary habits were assessed by a 169-item food frequency questionnaire (FFQ). Logistic regression analyses were performed to investigate the association between dietary patterns and the CRC risk.ResultsThree major dietary patterns were derived using factor analysis, namely a Meat-diet pattern, a Plant-based diet pattern and a Sugary-diet pattern. In combination the three dietary patterns explained 74% of the total variance in food intake. Results suggest that the Meat-diet and the Sugary-diet increased the risk of CRC with corresponding odds ratios (ORs) of 1.84 (95% CI: 1.19-2.86) and 2.26 (95% CI: 1.39-3.66) for people in the highest intake quintile compared to those in the lowest. Whereas plant-based diet pattern decreases the risk of CRC with a corresponding OR of 0.55 (95% CI: 0.35-0.87). Even though odds ratios (ORs) were not always statistically significant, largely similar associations across three cancer sites were found: the proximal colon, the distal colon, and the rectum.ConclusionThe finding that Meat-diet/Sugary-diet patterns increased and Plant-based diet pattern decreased the risk of CRC would guide the promotion of healthy eating for primary prevention of CRC in this population.

Occupational Exposure to Diesel and Gasoline Engine Emissions and Bladder Cancer Risk in Men: a Canadian Population-Based Case-Control Study

Background: The International Agency for Research on Cancer has classified diesel exhaust as a carcinogen and gasoline exhaust as a possible carcinogen based on evidence for lung cancer. Our goal was to determine whether a positive association exists between occupational exposure to diesel or gasoline exhaust and bladder cancer. Methods: A population-based design was used to recruit 670 cases and 2547 frequency-matched controls from eight Canadian provinces between 1994 and 1997. Lifetime occupational history, including job title, status and duties, and information on possible risk factors was obtained by self-reported questionnaire. Concentration and frequency of occupational exposure to diesel and gasoline exhaust, and a measure of the reliability of exposure assessment, was assigned for each job using a job-exposure matrix supplemented by expert review. Exposure metrics were modeled as ever-never, highest attained concentration, duration, and cumulative exposure. Unconditional logistic regression was used to calculate odds ratios and their 95% confidence intervals. Analyses were restricted to estimates with high reliability and adjustment was made for proxy respondent, province, age, smoking, alcohol, occupational silica and aromatic amine exposure. Results: Relative to unexposed men, elevated odds of bladder cancer were observed for men whose highest attained diesel exhaust exposure concentration was high (1.97, 1.08-3.58) and who spent more than 30% of time at work exposed to diesel (1.80, 1.02-3.15). A statistically significant trend in increased risk of bladder cancer was observed with increasing duration of exposure to medium/high concentrations of diesel exhaust (&gt;20 years, 1.82, 1.07-3.10, p-trend=0.002). We found no association between exposure to gasoline exhaust and bladder cancer. Conclusions: Our results suggest that occupational exposure to diesel exhaust increases bladder cancer risk in men, independent of smoking and other occupational exposures.

Abstract 4136: Comparison of overall survival of Chronic Lymphocytic Leukemia (CLL) patients referred or not referred to a specialized CLL clinic: A Canadian population-based study

Abstract Chronic Lymphocytic Leukemia (CLL) patients in Manitoba are either referred to the CancerCare Manitoba (CCMB) CLL clinic or receive care from other hematologists/general practitioners. However, it is unknown whether referral to the CLL-specialized clinic alters patients' outcome. All CLL/SLL diagnoses in Manitoba 2007-2011 were obtained from the Manitoba Cancer Registry to create an immunophenotipically confirmed population-based cohort. Referred patients to the CLL-specialized clinic were identified from the CCMB charts. Association between age and treatment was measured by chi-squared test. Hazard ratio (HR) was determined using Cox Proportional Hazard Regression model. Of 555 CLL/SLL diagnoses, 281 (51%) were referred to the CLL-specialized clinic. For referred and non-referred patients the median age was 68y (39-99) and 72y (45-96), treated patients were 77 (27%) and 31 (11%), time to first treatment was 5m (0-5.5y) and 3m (0-2.5y), respectively. M:F was 1.7:1 for both groups. CLL was the primary cause of death in both referred and non-referred patients (57% and 35%, respectively). Comorbidities such as cardiovascular diseases had equal contributions to mortality in both populations (7% and 9.5% in referred and non-referred patients, respectively). When patients older than 70 years were investigated, elderly patients that were referred to the clinic were more likely to receive treatment (p = 0.0002). When adjusted for age (≥80y HR 10.79, p: &amp;gt;0.0001; 71-79y HR 5.44, p: 0.0007; 62-70y HR 4.07, p: 0.0051; &amp;lt;62 HR 1.00), gender (male HR 1.61, p: 0.0414), pre-CLL cancer (HR 1.85, p: 0.0187) and post-CLL Cancer (HR 2.31 p: 0.0208), patients seen by CLL-specialists had a &amp;gt;2-fold increased OS compared to non-referred patients (HR 2.39, p: 0.0003) in the Manitoba population. In the non-referred population, there was a striking correlation between advancing age and decreasing OS. This correlation was almost eliminated in the referred population. Thus, patients seen in a specialized clinic have an improved survival compared to non-referred patients and this appears to be primarily related to improved OS in the elderly. Whether this observation is related to improved therapy/supportive care in the specialized clinic or to referral bias is under investigation. Citation Format: Sara Beiggi, Versha Banerji, Angela Deneka, Jane Griffith, Spencer Gibson, James Johnston. Comparison of overall survival of Chronic Lymphocytic Leukemia (CLL) patients referred or not referred to a specialized CLL clinic: A Canadian population-based study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4136. doi:10.1158/1538-7445.AM2014-4136

Incidence of coronary heart disease associated with arthritis: a Canadian population-based cohort study

Incidence of coronary heart disease associated with arthritis: a Canadian population-based cohort study

Association Between Evidence-Based Standardized Protocols in Emergency Departments With Childhood Asthma Outcomes: A Canadian Population-Based Study

P Li, T To, PC Parkin, GM Anderson, A Guttmann. Arch Pediatr Adolesc Med. 2012;166(9):834–840 To assess the utility of evidence-based standardized protocols (EBSPs) for children treated in emergency departments (EDs) for asthma compared with EDs with no standardized protocols (SPs) in Ontario, Canada. Children with previously diagnosed asthma ages 2 to 17 years ( N = 31 128) seen in 146 EDs in Ontario from April 2006 to March 2009. The primary outcome measure for this …

Long-term Residential Exposure to Air Pollution and Lung Cancer Risk

There is accumulating evidence that air pollution causes lung cancer. Still, questions remain about exposure misclassification, the components of air pollution responsible, and the histological subtypes of lung cancer that might be produced. We investigated lung cancer incidence in relation to long-term exposure to three ambient air pollutants and proximity to major roads, using a Canadian population-based case-control study. We compared 2,390 incident, histologically confirmed lung cancer cases with 3,507 population controls in eight Canadian provinces from 1994 to 1997. We developed spatiotemporal models for the whole country to estimate annual residential exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) over a 20-year exposure period. We carried out a subanalysis in urban centers, using exposures derived from fixed-site air pollution monitors, and also examined traffic proximity measures. Hierarchical logistic regression models incorporated a comprehensive set of individual and geographic covariates. The increase in lung cancer incidence (expressed as fully adjusted odds ratios [ORs]) was 1.29 (95% confidence interval = 0.95-1.76) with a ten-unit increase in PM2.5 (μg/m), 1.11 (1.00-1.24) with a ten-unit increase in NO2 (ppb), and 1.09 (0.85-1.39) with a ten-unit increase in O3 (ppb). The urban monitor-based subanalyses generally supported the national results, with larger associations for NO2 (OR = 1.34; 1.07-1.69) per 10 ppb increase. No dose-response trends were observed, and no clear relationships were found for specific histological cancer subtypes. There was the suggestion of increased risk among those living within 100 m of highways, but not among those living near major roads. Lung cancer incidence in this Canadian study was increased most strongly with NO2 and PM2.5 exposure. Further investigation is needed into possible effects of O3 on development of lung cancer.

Neighbourhood socioeconomic status and individual lung cancer risk: Evaluating long-term exposure measures and mediating mechanisms

Neighbourhood socioeconomic status (SES) has been associated with numerous chronic diseases, yet little information exists on its association with lung cancer incidence. This outcome presents two key empirical challenges: a long latency period that requires study participants' residential histories and long-term neighbourhood characteristics; and adequate data on many risk factors to test hypothesized mediating pathways between neighbourhood SES and lung cancer incidence. Analysing data on urban participants of a large Canadian population-based lung cancer case-control study, we investigate three issues pertaining to these challenges. First, we examine whether there is an association between long-term neighbourhood SES, derived from 20 years of residential histories and five national censuses, and lung cancer incidence. Second, we determine how this long-term neighbourhood SES association changes when using neighbourhood SES measures based on different latency periods or at time of study entry. Third, we estimate the extent to which long-term neighbourhood SES is mediated by a range of individual-level smoking behaviours, other health behaviours, and environmental and occupational exposures. Results of hierarchical logistic regression models indicate significantly higher odds of lung cancer cases residing in the most compared to the least deprived quintile of the long-term neighbourhood SES index (OR: 1.46; 95% CI: 1.13–1.89) after adjustment for individual SES. This association remained significant (OR: 1.38; 1.01–1.88) after adjusting for smoking behaviour and other known and suspected lung cancer risk factors. Important differences were observed between long-term and study entry neighbourhood SES measures, with the latter attenuating effect estimates by over 50 percent. Smoking behaviour was the strongest partial mediating pathway of the long-term neighbourhood SES effect. This research is the first to examine the effects of long-term neighbourhood SES on lung cancer risk and more research is needed to further identify specific, modifiable pathways by which neighbourhood context may influence lung cancer risk.

Increased risk of second malignancies in chronic lymphocytic leukaemia patients as compared with follicular lymphoma patients: a Canadian population-based study

Background:Chronic lymphocytic leukaemia (CLL) patients have an increased risk of other malignancies. This may be due to surveillance bias, treatment or immunosuppression.Methods:Cohort study of 612 consecutively diagnosed CLL patients in a Canadian province, with comparisons to follicular lymphoma (FL) patients.Results:Treated CLL patients had a 1.7-fold increased risk of second cancers compared with untreated CLL patients. As compared with untreated FL patients, untreated CLL patients had a two-fold increased incidence of second malignancies.Conclusion:Chronic lymphocytic leukaemia patients have an inherent predisposition to second cancers and the incidence is further increased by treatment.

Movement Disorders in Elderly Users of Risperidone and First Generation Antipsychotic Agents: A Canadian Population-Based Study

BackgroundDespite concerns over the potential for severe adverse events, antipsychotic medications remain the mainstay of treatment of behaviour disorders and psychosis in elderly patients. Second-generation antipsychotic agents (SGAs; e.g., risperidone, olanzapine, quetiapine) have generally shown a better safety profile compared to the first-generation agents (FGAs; e.g., haloperidol and phenothiazines), particularly in terms of a lower potential for involuntary movement disorders. Risperidone, the only SGA with an official indication for the management of inappropriate behaviour in dementia, has emerged as the antipsychotic most commonly prescribed to older patients. Most clinical trials evaluating the risk of movement disorders in elderly patients receiving antipsychotic therapy have been of limited sample size and/or of relatively short duration. A few observational studies have produced inconsistent results.MethodsA population-based retrospective cohort study of all residents of the Canadian province of Manitoba aged 65 and over, who were dispensed antipsychotic medications for the first time during the time period from April 1, 2000 to March 31, 2007, was conducted using Manitoba's Department of Health's administrative databases. Cox proportional hazards models were used to determine the risk of extrapyramidal symptoms (EPS) in new users of risperidone compared to new users of FGAs.ResultsAfter controlling for potential confounders (demographics, comorbidity and medication use), risperidone use was associated with a lower risk of EPS compared to FGAs at 30, 60, 90 and 180 days (adjusted hazard ratios [HR] 0.38, 95% CI: 0.22–0.67; 0.45, 95% CI: 0.28–0.73; 0.50, 95% CI: 0.33–0.77; 0.65, 95% CI: 0.45–0.94, respectively). At 360 days, the strength of the association weakened with an adjusted HR of 0.75, 95% CI: 0.54–1.05.ConclusionsIn a large population of elderly patients the use of risperidone was associated with a lower risk of EPS compared to FGAs.

Body mass index, lifetime smoking intensity and lung cancer risk

There is as yet no generally accepted explanation for the common finding that low body mass index (BMI) is associated with an increased risk of lung cancer. We investigated this association in a Canadian population-based case-control study (1996-2002) with a particular view to assessing the hypothesis that the observed association was due to residual confounding by smoking. Analyses were based on 1,076 cases and 1,439 controls who provided their height at enrollment and their weight at two points in time, at age 20 and 2 years before enrollment. BMI, in kg/m(2) , was classified into underweight (<18.5), normal (18.5-24.9), overweight (25.0-29.9), and obese (≥30). Smoking history was synthesized into a comprehensive smoking index (CSI) that integrated duration, intensity and time since quitting. Odds ratios (ORs) and 95% confidence intervals (CIs) for BMI-lung cancer associations were estimated, adjusting for CSI as well as several sociodemographic, lifestyle and occupational factors. The normal BMI category was used as the reference. Among those who were underweight at age 20, there was a lower risk of lung cancer (OR = 0.69, 95% CI: 0.50-0.95). Conversely, lung cancer risk was increased among those who were underweight 2 years before enrollment (OR = 2.30, 95% CI: 1.30-4.10). The results were almost identical when stratifying analyses based on smoking history into never/lighter and heavier smokers. The inverse association between recent BMI and lung cancer is unlikely to be largely attributable to residual confounding by smoking. Reverse causality or a true relationship between BMI and lung cancer remain plausible.

Influence of Maternal Factors on Health Outcomes in Gastroschisis: A Canadian Population-Based Study

Background: Gastroschisis is increasing in incidence worldwide. There is a need for a disease-specific, population-based approach to determining factors linked with gastroschisis and its outcome. Objectives: To examine racial, socioeconomic, health and geographic predictors of gastroschisis and its outcome in Canada. Methods: 535 cases of gastroschisis from the Canadian Pediatric Surgery Network national database were included from May 2005 to May 2010. Baseline characteristics of mothers were compared with those reported by Statistics Canada. Factors associated with adverse neonatal outcomes were examined using regression analyses. Results: Mothers of infants with gastroschisis are young, often from small communities. Smoking (37%) and illicit drug use are common in this population. Single mothers receive less perinatal care (OR 0.06; 95% CI 0.02–0.28). Geographically isolated mothers are more likely to undergo caesarian section (OR 3.84; 95% CI 1.26–11.74). Cocaine use predicts a lower odds of delivering at a planned center (OR 0.25; 95% CI 0.08–0.79), and is also associated with an increased likelihood of intestinal injury at birth (OR 6.26; 95% CI 1.52–25.72). Infants of mothers from isolated communities will spend a mean of 31.9 days longer in hospital. Aboriginal status is not independently predictive of perinatal or neonatal outcome. Conclusion: Gastroschisis in Canada occurs frequently in young mothers, aboriginals and smokers. Features associated with worse outcomes include single parent status, cocaine use and maternal hometown geographic isolation.

Spatiotemporal air pollution exposure assessment for a Canadian population-based lung cancer case-control study

BackgroundFew epidemiological studies of air pollution have used residential histories to develop long-term retrospective exposure estimates for multiple ambient air pollutants and vehicle and industrial emissions. We present such an exposure assessment for a Canadian population-based lung cancer case-control study of 8353 individuals using self-reported residential histories from 1975 to 1994. We also examine the implications of disregarding and/or improperly accounting for residential mobility in long-term exposure assessments.MethodsNational spatial surfaces of ambient air pollution were compiled from recent satellite-based estimates (for PM2.5 and NO2) and a chemical transport model (for O3). The surfaces were adjusted with historical annual air pollution monitoring data, using either spatiotemporal interpolation or linear regression. Model evaluation was conducted using an independent ten percent subset of monitoring data per year. Proximity to major roads, incorporating a temporal weighting factor based on Canadian mobile-source emission estimates, was used to estimate exposure to vehicle emissions. A comprehensive inventory of geocoded industries was used to estimate proximity to major and minor industrial emissions.ResultsCalibration of the national PM2.5 surface using annual spatiotemporal interpolation predicted historical PM2.5 measurement data best (R2 = 0.51), while linear regression incorporating the national surfaces, a time-trend and population density best predicted historical concentrations of NO2 (R2 = 0.38) and O3 (R2 = 0.56). Applying the models to study participants residential histories between 1975 and 1994 resulted in mean PM2.5, NO2 and O3 exposures of 11.3 μg/m3 (SD = 2.6), 17.7 ppb (4.1), and 26.4 ppb (3.4) respectively. On average, individuals lived within 300 m of a highway for 2.9 years (15% of exposure-years) and within 3 km of a major industrial emitter for 6.4 years (32% of exposure-years). Approximately 50% of individuals were classified into a different PM2.5, NO2 and O3 exposure quintile when using study entry postal codes and spatial pollution surfaces, in comparison to exposures derived from residential histories and spatiotemporal air pollution models. Recall bias was also present for self-reported residential histories prior to 1975, with cases recalling older residences more often than controls.ConclusionsWe demonstrate a flexible exposure assessment approach for estimating historical air pollution concentrations over large geographical areas and time-periods. In addition, we highlight the importance of including residential histories in long-term exposure assessments.For submission to: Environmental Health

Ten Years of Antipsychotic Prescribing to Children: A Canadian Population-Based Study

To report the prescribing of antipsychotics to the youth population of the Canadian province of Manitoba during the course of a decade. Use of antipsychotics in children and adolescents (aged 18 years or younger) was described using data collected from the administrative health databases of Manitoba Health and the Statistics Canada census between the fiscal years of 1999 and 2008. The prevalence of antipsychotic use in this segment of the population increased with the introduction of the second-generation antipsychotics (SGAs) from 1.9 per 1000 in 1999 to 7.4 per 1000 in 2008. The male-to-female antipsychotic usage ratio increased from 1.9 to 2.7 as the male youth population represented the fastest-growing subgroup of antipsychotic users in the entire population of Manitoba. The total number of prescriptions also increased significantly despite the lack of approved indications in this population. Proportion of use remained equally split between high- and low-income users. More than 70% of antipsychotic prescriptions to children and adolescents were written by general practitioners. The most common diagnoses linked to antipsychotic use were attention-deficit hyperactivity disorder and conduct disorders. Use of antipsychotics in combination with methylphenidate increased from 13% to 43%. Extensive off-label use of SGAs has been observed in the youth population of Manitoba for treatment of aggressive behaviours across a range of diagnoses. It is important to monitor antipsychotic prescribing to children as more reports of significant adverse events associated with antipsychotics become available.

Bugs and Drugs: Insights into the Pathogenesis of Inflammatory Bowel Disease

The dysbiosis hypothesis posits that perturbations in the gut microbiome may contribute to the development of inflammatory bowel disease (IBD). A recent Canadian population-based study has shown an association between new-onset IBD and antibiotic use in the 2-5 years preceding diagnosis. Though these findings do not establish a causal relationship, it supports the role of dysbiosis in the pathogenesis of IBD. Furthermore, the study reinforces the importance of the judicious use of antibiotics.

Direct Medical Cost of Managing IBD Patients: A Canadian Population-based Study

This study aimed to quantify the direct medical cost of treating inflammatory bowel disease (IBD) in Manitoba in 2005/2006. In all, 7375 individuals with IBD recorded in the University of Manitoba IBD Epidemiology Database were matched on age, gender, and geography to up to 10 non-IBD controls. Data for cases and controls were extracted from Manitoba Health databases in fiscal 2005/2006 for pharmaceutical, physician claims, and hospital abstracts. The mean and median expenditure were computed for the annual cost of pharmaceuticals, hospitalizations (day surgery and inpatient), and physician office visits. We assessed costs based on age, gender, type of IBD, disease duration, and level of care provided. In 2005/2006 the mean direct cost of an IBD case was $3896 (standard error [SE] = $90) which was twice that of controls (P < 0.05). Crohn's disease (CD; n = 3735) was significantly more costly on average than ulcerative colitis (UC; n = 3640) ($4232; SE = $137 and $3552; SE = $117, respectively, P < 0.001). The most costly cases included those within 1 year of diagnosis ($6611; SE = $593), those hospitalized overnight (15%) ($13,495, SE = $416; max = $130,332), those who had a surgical stay (2% of IBD cases) ($18,749, range = $13,413-$125,912), and those using infliximab (0.7%) ($31,440, SE = $2311; max = $96,328). For individuals using infliximab their direct annual average healthcare cost was $9683 (SE = $1745, Max = $55,208) prior to using infliximab. In Manitoba the direct average annual healthcare cost of CD is greater than UC and that of a patient using infliximab tends to be greater than one incurring a surgical stay.

Soft-Tissue Sarcoma and Pesticides Exposure in Men

The objective was to investigate the putative associations of specific pesticides with soft-tissue sarcoma (STS). A Canadian population-based case-control study conducted in six provinces was used in this analysis. The study design consisted of two stages: a self-administered postal questionnaire and a telephone interview for those reporting pesticides exposure of 10 hours per year or more; and a 15% random sample of the remainder. Conditional logistic regression was used to fit the statistical models. A positive history of cancer among first-degree relatives and exposure to aldrin and diazinon were statistically significant independent predictors of an increased risk for STS, whereas diagnosis of whopping cough lowered the risk of STS. The incidence of STS was associated with specific insecticides after adjustment for other independent predictors.