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BACKGROUND: The Ottawa Hospital (toh) defined delay to timely lung cancer care as a system design problem. Recognizing the patient need for an integrated journey and the need for dynamic alignment of providers, toh used a learning health system (lhs) vision to redesign regional diagnostic processes. A lhs is driven by feedback utilizing operational and clinical information to drive system optimization and innovation. An essential component of a lhs is a collaborative platform that provides connectivity across silos, organizations, and professions. METHODS: To operationalize a lhs, we developed the Ottawa Health Transformation Model (ohtm) as a consensus approach that addresses process barriers, resistance to change, and conflicting priorities. A regional Community of Practice (cop) was established to engage stakeholders, and a dedicated transformation team supported process improvements and implementation. RESULTS: The project operationalized the lung cancer diagnostic pathway and optimized patient flow from referral to initiation of treatment. Twelve major processes in referral, review, diagnostics, assessment, triage, and consult were redesigned. The Ottawa Hospital now provides a diagnosis to 80% of referrals within the provincial target of 28 days. The median patient journey from referral to initial treatment decreased by 48% from 92 to 47 days. CONCLUSIONS: The initiative optimized regional integration from referral to initial treatment. Use of a lhs lens enabled the creation of a system that is standardized to best practice and open to ongoing innovation. Continued transformation initiatives across the continuum of care are needed to incorporate best practice and optimize delivery systems for regional populations.
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There is no standard methodology or guideline for assessing soil microbial health for the purposes of contaminant risk assessments. Here we propose a laboratory-based test suite and novel data integration method for evaluating soil microbial health using site-specific contaminated and reference soil. The test suite encompasses experiments for evaluating microbial biomass, activity, and diversity. The results from the tests are then integrated so that a Soil Microbial Health Score (SMHS) may be assigned. This test suite and data integration method was tested on soils from 3 different contaminated sites in Canada. The soil microbial health of a petroleum hydrocarbon (PHC) contaminated site was found to be 'Mildly Impacted' and 'Moderately Impacted' for two soil horizons at a boreal forest site. The soil microbial health of the mixed metal/PHC and mixed metal sites were both found to be 'Not Impacted'. Continued use of this test suite and data integration method will help create guidelines for assessing soil microbial health in ecological risk assessments.
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Biota/efectos de los fármacos , Interpretación Estadística de Datos , Contaminación Ambiental , Técnicas Microbiológicas/métodos , Microbiología del Suelo , Canadá , Bosques , Metagenómica/métodos , Petróleo/análisis , Contaminantes del Suelo/análisisRESUMEN
INTRODUCTION: Although e-cigarette use ("vaping") is increasing in Canada, few attempts have been made to describe e-cigarette users ("vapers"). In this context, we conducted a study in Ottawa, Canada, to describe e-cigarette users' perceptions of the benefits, harms and risks of e-cigarettes. We also collected information on why, how and where they use e-cigarettes as well as information on side effects. METHODS: A 24-item online survey was administered to individuals who purchased e-cigarettes or e-cigarette-related supplies at one of Ottawa's 17 e-cigarette shops. Descriptive analyses characterized respondents, and logistic regression models were fitted to evaluate the relationship between respondents' characteristics and their perception of e-cigarette harms. RESULTS: The mean age of the 242 respondents was 38.1 years (range: 16-70 years); 66% were male. Nearly all had smoked 100 or more cigarettes in their lifetime (97.9%). More than 80% indicated that quitting smoking was a very important reason for starting to use e-cigarettes and 60% indicated that they intend to stop using e-cigarettes at some point. About 40% reported experiencing some side effects within 2 hours of using e-cigarettes. Those who did not report experiencing any of the listed side effects had approximately 3.2 times higher odds of perceiving e-cigarettes as harmless than those who reported having side effects (odds ratio = 3.17; 95% confidence interval: 1.75-5.73). CONCLUSION: Our findings suggest that most e-cigarette users are using them to reduce or stop smoking cigarettes and perceive them as harmless. Due to our use of convenience sampling, the reader should be cautious in generalizing our findings to all Canadian e-cigarette users.
INTRODUCTION: Bien que l'utilisation de la cigarette électronique (« vapotage ¼) soit en hausse au Canada, peu d'efforts ont été consacrés à la description des utilisateurs de cigarettes électroniques (« vapoteurs ¼). C'est dans ce contexte que nous avons mené une étude à Ottawa (Canada) afin de décrire les perceptions qu'ont les utilisateurs de cigarettes électroniques des avantages, des dangers et des risques de ces dernières. Nous avons également recueilli de l'information pour savoir pourquoi, comment et où ils utilisent la cigarette électronique ainsi que sur les effets secondaires. MÉTHODOLOGIE: Un sondage en ligne de 24 questions a été soumis à des personnes ayant acheté des cigarettes électroniques ou des fournitures connexes dans l'un des 17 commerces de cigarettes électroniques à Ottawa. On a caractérisé les répondants au moyen d'analyses descriptives, puis nous avons appliqué des modèles de régression logistique pour évaluer la relation entre ces caractéristiques et la perception par les répondants des dangers de la cigarette électronique. RÉSULTATS: L'âge moyen des 242 répondants était de 38,1 ans (plage : 16 à 70 ans) et, de ce nombre, 66 % étaient des hommes. Près de la totalité (97,9 %) des répondants avaient fumé 100 cigarettes ou plus au cours de leur vie. Plus de 80 % des répondants ont indiqué que la volonté d'arrêter de fumer constituait l'une des principales raisons de recourir à la cigarette électronique, et 60 % ont mentionné qu'ils avaient l'intention de cesser l'utilisation de la cigarette électronique un jour. Environ 40 % des répondants ont fait état d'effets secondaires au cours des 2 heures suivant l'utilisation des cigarettes électroniques. Les répondants ayant signalé n'avoir ressenti aucun des effets secondaires énumérés étaient environ 3,2 fois plus nombreux à ne percevoir aucun danger dans la cigarette électronique que les personnes ayant signalé des effets secondaires (rapport de cotes = 3,17; intervalle de confiance à 95 % : 1,75 à 5,73). CONCLUSION: D'après nos constatations, la majorité des utilisateurs de cigarettes électroniques ont recours à ces dernières pour réduire ou cesser leur consommation de tabac et ils les perçoivent comme inoffensives. Étant donné que nous avons utilisé un échantillonnage de commodité, le lecteur doit faire preuve de prudence dans la généralisation de nos constatations à tous les utilisateurs de cigarettes électroniques au Canada.
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Sistemas Electrónicos de Liberación de Nicotina , Adolescente , Adulto , Anciano , Canadá/epidemiología , Sistemas Electrónicos de Liberación de Nicotina/efectos adversos , Sistemas Electrónicos de Liberación de Nicotina/psicología , Sistemas Electrónicos de Liberación de Nicotina/estadística & datos numéricos , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Medición de Riesgo , Fumar/epidemiología , Fumar/psicología , Cese del Hábito de Fumar/métodos , Cese del Hábito de Fumar/psicología , Percepción SocialRESUMEN
This study aimed to study the factors that are associated with urgent esophagectomy for the treatment of esophageal perforations and the impact of this therapy. A retrospective review of all esophageal perforations treated at a tertiary care hospital from January 1984 to January 2012 was performed. Compiling demographics, cause and site of perforations, time to presentation, comorbidities, radiological tests, the length of perforation, the hemodynamic status of the patient, type of treatment required, and outcomes were performed. Univariate, multivariate, and Cox regression analyses were conducted. Of 127 cases of esophageal perforation, it was spontaneous in 44 (35%), iatrogenic in 53 (44%), foreign body ingestion in 22 (17%), and traumatic perforation in 7 (6%) cases. Overall, 85 of the 127 (67%) patients were managed operatively, 35 (27.6%) patients were treated conservatively, and 7 (6.3%) patients were treated by endoscopic stent placement. Of the 85 patients who were managed operatively, 21 (16.5%) required esophagectomies, 13 (15.3%) had esophagectomy with immediate reconstruction, 5 (5.9%) patients had esophagectomy followed by delayed reconstruction, and 3 (3.5%) patients failed primary repair and required an esophagectomy as a secondary definitive procedure. Multivariate analysis revealed that esophagectomy in esophageal perforations was associated with the presence of benign or malignant esophageal stricture (P = 0.001) and a perforation >5 cm (P = 0.001). Mortality was mainly associated with the presence of a benign or malignant esophageal stricture (P = 0.04). The presence of pre-existing benign or malignant stricture or large perforation (>5 cm) is associated with the need for an urgent esophagectomy with or without immediate reconstruction. Performing esophagectomy was not found to be a significant prognosticator for mortality.
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Perforación del Esófago , Esofagectomía , Adulto , Anciano , Anciano de 80 o más Años , Perforación del Esófago/diagnóstico , Perforación del Esófago/etiología , Perforación del Esófago/mortalidad , Perforación del Esófago/fisiopatología , Perforación del Esófago/cirugía , Estenosis Esofágica/complicaciones , Estenosis Esofágica/diagnóstico , Esofagectomía/efectos adversos , Esofagectomía/instrumentación , Esofagectomía/métodos , Esofagectomía/estadística & datos numéricos , Esófago/diagnóstico por imagen , Esófago/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Arabia Saudita/epidemiología , Índice de Severidad de la Enfermedad , Stents , Tiempo de Tratamiento/estadística & datos numéricosRESUMEN
TITRE: Rapport d'étape - Historique des débuts de la surveillance nationale des maladies chroniques au Canada et rôle majeur du Laboratoire de lutte contre la maladie (LLCM) de 1972 à 2000. INTRODUCTION: La surveillance de la santé consiste en l'utilisation systématique et continue de données sur la santé recueillies régulièrement en vue d'orienter les mesures de santé publique en temps opportun. Ce document décrit la création et l'essor des systèmes nationaux de surveillance au Canada et les répercussions de ces systèmes sur la prévention des maladies chroniques et des blessures. En 2008, les auteurs ont commencé à retracer l'historique des débuts de la surveillance nationale des maladies chroniques au Canada, en commençant à 1960, et ils ont poursuivi leur examen jusqu'en 2000. Une publication de 1967 a retracé l'historique de la création du Laboratoire d'hygiène de 1921 à 1967. Notre étude fait suite à cette publication et décrit l'historique de l'établissement de la surveillance nationale des maladies chroniques au Canada, à la fois avant et après la création du Laboratoire de lutte contre la maladie (LCDC).
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Enfermedad Crónica , Agencias Gubernamentales , Salud Pública , Canadá , Enfermedad Crónica/epidemiología , Enfermedad Crónica/prevención & control , Agencias Gubernamentales/historia , Agencias Gubernamentales/organización & administración , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Vigilancia de la Población , Salud Pública/métodos , Salud Pública/tendenciasRESUMEN
To assess the long-term risk of developing cancer among heart transplant recipients compared to the Canadian general population, we carried out a retrospective cohort study of 1703 patients who received a heart transplant between 1981 and 1998, identified from the Canadian Organ Replacement Register database. Vital status and cancer incidence were determined through record linkage to the Canadian Mortality Database and Canadian Cancer Registry. Cancer incidence rates among heart transplant patients were compared to those of the general population. The observed number of incident cancers was 160 with 58.9 expected in the general population (SIR = 2.7, 95% CI = 2.3, 3.2). The highest ratios were for non-Hodgkin's lymphoma (NHL) (SIR = 22.7, 95% CI = 17.3, 29.3), oral cancer (SIR = 4.3, 95% CI = 2.1, 8.0) and lung cancer (SIR = 2.0, 95% CI = 1.2, 3.0). Compared to the general population, SIRs for NHL were particularly elevated in the first year posttransplant during more recent calendar periods, and among younger patients. Within the heart transplant cohort, overall cancer risks increased with age, and the 15-year cumulative incidence of all cancers was estimated to be 17%. There is an excess of incident cases of cancer among heart transplant recipients. The relative excesses are most marked for NHL, oral and lung cancer.
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Cardiopatías/complicaciones , Cardiopatías/terapia , Trasplante de Corazón/métodos , Neoplasias/complicaciones , Neoplasias/epidemiología , Adolescente , Adulto , Canadá , Niño , Estudios de Cohortes , Femenino , Humanos , Incidencia , Linfoma no Hodgkin/complicaciones , Linfoma no Hodgkin/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/complicaciones , Neoplasias de la Boca/epidemiología , Riesgo , Resultado del TratamientoRESUMEN
Urban air pollution has been associated with morbidity but little information exists on how it affects diurnal variation of lung function in children with asthma. The purpose of this study was to investigate the acute effects of traffic-related pollution on lung function among children with asthma. We recorded morning and evening forced expiratory volume in 1 s (FEV(1)) for 28 consecutive days in 182 elementary schoolchildren with physician-diagnosed asthma, and monitored ambient hourly air pollution concentrations. An interquartile range (IQR) increase (6.0 microg m(-3)) in the previous 24-h (20:00 h to 20:00 h) mean concentration of fine particulate matter 2.5 microm in diameter (PM(2.5)) was associated with a 0.54% (95% confidence interval (CI) 0.06-1.02) decrease in bedtime FEV(1) (p = 0.027). This association persisted in two-pollutant models with ozone, nitrogen dioxide and sulphur dioxide. An IQR increase in mean daytime (08:00 h to 20:00 h) PM(2.5) of 6.5 microg m(-3) was associated with a 0.73% (95% CI 0.10-1.37) decrease in FEV(1) over the course of the day expressed as 100 x (FEV(1) bedtime - FEV(1) morning)/FEV(1) morning (p = 0.024). This study suggests that, in children with asthma, relatively low concentrations of urban air pollution worsen lung function over a short period of time, even within a day. Of the pollutants measured, PM(2.5 )appears to be the most important.
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Contaminación del Aire , Asma/diagnóstico , Asma/etiología , Volumen Espiratorio Forzado , Exposición por Inhalación , Enfermedad Aguda , Adolescente , Contaminantes Atmosféricos , Niño , Ciudades , Femenino , Humanos , Estudios Longitudinales , Masculino , Dióxido de Nitrógeno/análisis , Ozono/análisis , Dióxido de Azufre/análisisRESUMEN
Radon is known to cause lung cancer in humans; however, there remain uncertainties about the effects associated with residential exposures. This case-control study of residential radon and lung cancer was conducted in five counties in New Jersey and involved 561 cases and 740 controls. A year long alpha-track detector measurement of radon was completed for approximately 93% of all residences lived in at the time of interview (a total of 2,063). While the odds ratios (ORs) for whole data were suggestive of an increased risk for exposures >75 Bq m(-3), these associations were not statistically significant. The adjusted excess OR (EOR) per 100 Bq m(-3) was -0.13 (95% CI: -0.30 to 0.44) for males, 0.29 (95% CI: -0.12 to 1.70) for females and 0.05 (95% CI: -0.14 to 0.56) for all subjects combined. An analysis of radon effects by histological type of lung cancer showed that the OR was strongest for small/oat cell carcinomas in both males and females. There was no statistical heterogeneity of radon effects by demographic factors (age at disease occurrence, education level and type of respondent). Analysis by categories of smoking status, frequency or duration did not modify the risk estimates of radon on lung cancer. The findings of this study are consistent with an earlier population-based study of radon and lung cancer among New Jersey women, and with the North American pooling of case control radon seven studies, including the previous New Jersey study. Several uncertainties regarding radon measurements and assumptions of exposure history may have resulted in underestimation of a true exposure-response relationship.
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Contaminantes Radiactivos del Aire/efectos adversos , Contaminación del Aire Interior/efectos adversos , Carcinógenos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/efectos adversos , Neoplasias Pulmonares/etiología , Neoplasias Inducidas por Radiación/etiología , Radón/efectos adversos , Anciano , Estudios de Casos y Controles , Femenino , Vivienda , Humanos , Neoplasias Pulmonares/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/epidemiología , New Jersey/epidemiología , Oportunidad Relativa , Factores de RiesgoRESUMEN
A number of studies have observed increased cancer incidence rates among individuals who have received renal transplants. Generally, however, these studies have been limited by relatively small sample sizes, short follow-up intervals or focused on only one cancer site. We conducted a nationwide population-based study of 11,155 patients who underwent kidney transplantation between 1981 and 1998. Incident cancers were identified up to December 31, 1999, through record linkage to the Canadian Cancer Registry. Patterns of cancer incidence in the cohort were compared to the Canadian general population using standardized incidence ratios (SIRs). We examined variations in risk according time since transplantation, year of transplantation and age at transplantation. In our patient population, we observed a total of 778 incident cancers versus 313.2 expected (SIR = 2.5, 95% CI = 2.3-2.7). Site-specific SIRs were highest for cancer of the lip (SIR = 31.3, 95% CI = 23.5-40.8), non-Hodgkin's lymphoma (NHL) (SIR = 8.8, 95% CI = 7.4-10.5), and kidney cancer (SIR = 7.3, 95% CI = 5.7-9.2). SIRs for NHL and cancer of the lip and kidney were highest and among transplant patients. This study confirms previous findings of increased risks of posttransplant cancer. Our findings underscore the need for increased vigilance among kidney transplant recipients for cancers at sites where there are no population-based screening programs in place.
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Trasplante de Riñón/efectos adversos , Trasplante de Riñón/estadística & datos numéricos , Neoplasias/epidemiología , Adolescente , Adulto , Anciano , Canadá , Niño , Bases de Datos Factuales , Femenino , Estudios de Seguimiento , Humanos , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/cirugía , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Neoplasias/mortalidad , Complicaciones Posoperatorias/epidemiología , Prevalencia , Sistema de Registros , Terapia de Reemplazo Renal/estadística & datos numéricos , Análisis de SupervivenciaRESUMEN
BACKGROUND: While a number of studies suggest that air pollution is associated with allergic rhinitis in children, findings among adults have been equivocal. The aim of this study was to examine the relationship between outdoor air pollution and physician visits for allergic rhinitis among individuals>or=65 years of age in Toronto, Canada. METHODS: Physician visits were identified by using data from the Ontario provincial health insurance plan that is made available to all residents. Our analyses are based on 52,691 physician visits for allergic rhinitis among individuals>or=65 years of age in the Toronto metropolitan area between 1995 and 2000. Generalized linear models were used to regress daily counts of physician visits against daily measures of gaseous and particulate components of air pollution after controlling for seasonality, potential confounders (temperature, relative humidity, aeroallergens), overdispersion and serial correlation. RESULTS: A large number of comparisons were undertaken, with most showing no statistically significant associations between daily levels of air pollution and the number of physician visits for rhinitis. In contrast, an interquartile increase in the 10-day average of ragweed particles increased the mean number of daily rhinitis consultations by 6.4% (95% CI=0.7-12.4%). CONCLUSIONS: Our findings suggest that outdoor air pollution is a poor predictor of physician visits for allergic rhinitis among the elderly.
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Contaminantes Atmosféricos/efectos adversos , Médicos/estadística & datos numéricos , Rinitis Alérgica Perenne/fisiopatología , Rinitis Alérgica Estacional/fisiopatología , Anciano , Humanos , Ontario , Rinitis Alérgica Perenne/terapia , Rinitis Alérgica Estacional/terapia , Estaciones del AñoRESUMEN
BACKGROUND: Self-reported surveys have indicated that weather can trigger migraine headaches. However, to date, we know of no previous study that has examined the relationship between weather and emergency room (ER) visits for this condition. OBJECTIVE: To examine associations between ER visits for migraines and selected meteorological conditions within the 24 hours preceding the visit. DESIGN AND METHODS: A case-crossover design was used to study 4039 visits for migraines (ICD-9: 346) that occurred at an Ottawa hospital between 1993 and 2000. Meteorological conditions were defined using hourly readings from a fixed-site monitoring station. Conditional logistic regression was used to compare the occurrence of meteorological conditions during the 24 hours leading up to the time of the visit to control periods occurring 1 week before and after. RESULTS: Precipitation-related weather events (fog, snow, rain, thunder) were not associated with migraine visits. Similarly, no associations were observed with changes in atmospheric pressure, wind speed, and relative humidity during the 24 hours preceding presentation. No statistically significant differences in the frequency distribution of clusters defined by relative humidity, atmospheric pressure, and temperature were found between case and control intervals. Conversely, a mean wind speed in excess of 19 km per hour was associated with a reduction in ER visits 8 to 12 hours later. CONCLUSIONS: Our findings provide little support for the hypothesis that ER visits for migraines are related to weather conditions occurring within the 24 hours preceding presentation. These results should be interpreted cautiously as some comparisons are based on a small number of cases, and ER visits for migraine may represent a highly selective group of patients who suffer from this condition.
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Servicios Médicos de Urgencia/estadística & datos numéricos , Trastornos Migrañosos/epidemiología , Tiempo (Meteorología) , Adulto , Estudios Cruzados , Femenino , Humanos , Masculino , Trastornos Migrañosos/terapia , Oportunidad Relativa , Ontario/epidemiologíaRESUMEN
Following the validation and replication of the Harvard Six Cities Study (Krewski et al., this issue), we conducted a wide range of sensitivity analyses to explore the observed associations between long-term exposure to fine particle or sulfate air pollution and mortality. We examined the impact of alternative risk models on estimates of risk, taking into account covariates not included in the original analyses. These risk models provided a basis for identifying covariates that may confound or modify the association between fine particle or sulfate air pollution and mortality, and for identifying sensitive population subgroups. The possibility of confounding due to occupational exposures was also investigated. Residence histories were coded for the study subjects and were used to examine temporal patterns of exposure and risk. Our sensitivity analyses showed the mortality risk estimates for fine particle and sulfate air pollution to be highly robust against alternative risk models of the Cox proportional hazards family, including models with additional covariates from the original questionnaires not included in the original published analyses. There was limited evidence of departures from the proportional hazards assumption. Flexible exposure-response models provided some evidence of departures from linearity at both low and high sulfate concentrations. Incorporating information on changes over time in cigarette smoking and body mass index had little effect on the association between fine particles and mortality. There was limited evidence of variation in risk with attained age, gender, smoking status, occupational exposure to dust and fumes, marital status, heart or lung diseases, or lung function. However, air pollution risk did appear to decreasing with increasing educational attainment. Extensive adjustment for occupation using aggregate indices of occupational "dirtiness" and occupational exposure to known lung carcinogens had little impact on the mortality risks associated with particulate air pollution. Our evaluation of population mobility indicated that relatively few subjects moved from their original city of residence. Attempts to identify critical exposure time windows were limited by the lack of marked interindividual variation in temporal exposure patterns throughout the study period. Overall, this extensive sensitivity analysis both supported the conclusions reached by the original investigators and demonstrated the robustness of these conclusions to alternative analytic approaches.
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Contaminantes Atmosféricos/envenenamiento , Enfermedades Cardiovasculares/mortalidad , Exposición a Riesgos Ambientales , Enfermedades Pulmonares/mortalidad , Exposición Profesional , Factores de Edad , Enfermedades Cardiovasculares/etiología , Estudios de Cohortes , Polvo , Femenino , Humanos , Enfermedades Pulmonares/etiología , Masculino , Persona de Mediana Edad , Control de Calidad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estados Unidos , United States Environmental Protection Agency , Población Urbana , Emisiones de VehículosRESUMEN
STUDY OBJECTIVE: Assess associations between short-term exposure to gaseous pollutants and asthma hospitalisation among boys and girls 6 to12 years of age. DESIGN: A bi-directional case-crossover analysis was used. Conditional logistic regression models were fitted to the data for boys and girls separately. Exposures averaged over periods ranging from one to seven days were used to assess the effects of gaseous pollutants on asthma hospitalisation. Estimated relative risks for asthma hospitalisation were calculated for an incremental exposure corresponding to the interquartile range in pollutant levels, adjusted for daily weather conditions and concomitant exposure to particulate matter. SETTING: Toronto, Ontario, Canada. PARTICIPANTS: A total of 7319 asthma hospitalisations for children 6 to 12 years of age (4629 for boys and 2690 for girls) in Toronto between 1981 and 1993. MAIN RESULTS: A significant acute effect of carbon monoxide on asthma hospitalisation was found in boys, and sulphur dioxide showed significant effects of prolonged exposure in girls. Nitrogen dioxide was positively associated with asthma admissions in both sexes. The lag time for certain gaseous pollutant effects seemed to be shorter in boys (around two to three days for carbon monoxide and nitrogen dioxide), as compared with girls (about six to seven days for sulphur dioxide and nitrogen dioxide). The effects of gaseous pollutants on asthma hospitalisation remained after adjustment of particulate matter. The data showed no association between ozone and asthma hospitalisation in children. CONCLUSIONS: The study showed positive relations between gaseous pollutants (carbon monoxide, sulphur dioxide, and nitrogen dioxide) at comparatively low levels and asthma hospitalisation in children, using bi-directional case-crossover analyses. Though, the effects of certain specific gaseous pollutants were found to vary in boys and girls.
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Contaminantes Atmosféricos/efectos adversos , Asma/epidemiología , Hospitalización/estadística & datos numéricos , Asma/etiología , Monóxido de Carbono/efectos adversos , Niño , Estudios Cruzados , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Gases/efectos adversos , Humanos , Modelos Logísticos , Masculino , Dióxido de Nitrógeno/efectos adversos , Oportunidad Relativa , Ontario/epidemiología , Ozono/efectos adversos , Análisis de Regresión , Dióxido de Azufre/efectos adversosRESUMEN
To explore the hypothesis that insulin resistance may be an etiologic factor in pancreatic cancer, we assessed the pancreatic cancer risk associated with anthropometric factors and physical activity, both of which are important determinants of insulin sensitivity in humans. Three hundred and twelve patients with histologically confirmed pancreatic cancer were compared to 2,919 controls in a population-based, case-control study in 7 of the 10 Canadian provinces. Participants were asked to report their exposure status for the period 2 years before interview. Men in the highest quartile of body mass index (BMI, > or =28.3 kg/m(2)) were at increased risk of pancreatic cancer [adjusted odds ratio (OR) = 1.90, 95% confidence interval (CI) 1.08-3.35]. In addition, men who reported a decrease in weight of at least 2.9% from their lifetime maximum were at reduced risk compared to those reporting a < or =2.9% loss (> or =10.2% loss, OR = 0.51, 95% CI 0.30-0.86). BMI 2 years before interview was not associated with pancreatic cancer risk among women, though those reporting a > or =12.5% decrease in weight from their lifetime maximum had substantially lower risk compared to those in the baseline quartile (OR = 0.53, 95% CI 0.29-0.99). After adjustment for age, province of residence, dietary intake and anthropometric factors, men in the highest quartile of the composite moderate and strenuous physical activity index were at reduced risk of pancreatic cancer (OR = 0.53, 95% CI 0.31-0.90). Physical activity did not appear to be associated with pancreatic cancer among women, though a tendency for reduced risk with increasing levels of strenuous activity was suggested (p for trend = 0.06). Our findings support the hypothesis that insulin resistance is an etiologic factor in the development of pancreatic neoplasms among men and possibly women.
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Neoplasias Pancreáticas/etiología , Factores de Edad , Índice de Masa Corporal , Ejercicio Físico , Femenino , Humanos , Resistencia a la Insulina , Masculino , Menarquia , Obesidad/complicaciones , Neoplasias Pancreáticas/mortalidad , Riesgo , Factores SexualesAsunto(s)
Infecciones por VIH/epidemiología , Personal de Salud/estadística & datos numéricos , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Transmisión de Enfermedad Infecciosa de Paciente a Profesional , Enfermedades Profesionales/epidemiología , Patógenos Transmitidos por la Sangre/aislamiento & purificación , Líquidos Corporales/microbiología , Líquidos Corporales/virología , Canadá/epidemiología , Femenino , Infecciones por VIH/transmisión , Hepatitis B/transmisión , Hepatitis C/transmisión , Humanos , Incidencia , Masculino , Enfermedades Profesionales/diagnóstico , Vigilancia de la Población , Factores de RiesgoRESUMEN
OBJECTIVES: To examine associations between non-Hodgkin's lymphoma (NHL) and exposures to 60 Hz magnetic and electric fields in electric utility workers with a series of indices that capture a variety of aspects of field strength. METHODS: The study population consisted of 51 cases of NHL and 203 individually matched controls identified from within a cohort of male electric utility workers in Ontario. Odds ratios were calculated for several exposure indices with conditional logistic regression models. Aspects of exposure to electric and magnetic fields that were modelled included: the percentage of time spent above selected threshold field intensities, mean transitions in field strength, SD, and the arithmetic and geometric mean field intensities. RESULTS: For the most part, there was a lack of an association between exposure indices of magnetic fields and the incidence of NHL. Subjects in the upper tertile of percentage of time spent above electric field intensities of 10 and 40 V/m had odds ratios of 3.05 (95% confidence interval (95% CI) 1. 07 to 8.80) and 3.57 (1.30 to 9.80), respectively, when compared with those in the lowest tertile. Moreover, the percentages of time spent above these electric field thresholds were significant predictors of case status over and above the association explained by duration of employment and the arithmetic or geometric mean exposure. CONCLUSIONS: These data suggest that exposures above electric field threshold intensities of 10 and 40 V/m are important predictors of NHL. Consequently, the findings support the hypothesis that electric fields may play a promoting part in the aetiology of this cancer. Further occupational studies that include assessment of exposure to electric fields and measures of field strength above similar threshold cut off points are needed to confirm these findings.
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Campos Electromagnéticos/efectos adversos , Linfoma no Hodgkin/epidemiología , Enfermedades Profesionales/epidemiología , Exposición Profesional/efectos adversos , Estudios de Casos y Controles , Humanos , Linfoma no Hodgkin/etiología , Masculino , Enfermedades Profesionales/etiología , Ontario/epidemiología , Centrales EléctricasRESUMEN
BACKGROUND: Epidemiological studies have inconsistently demonstrated a positive relationship between magnetic and/or electric fields and leukemia. Although exposure to both 60 Hz electric and magnetic fields can be characterized in many ways, to date, risk assessment has been performed by using only a limited number of exposure indices. METHODS: The associations between adult leukemia and indices of electric and magnetic fields were explored within a nested case-control study of 31,453 Ontario electric utility workers. RESULTS: The percentage of time spent above electric field thresholds of 20 and 39 V/m was predictive of leukemia risk after adjusting for duration of employment and the arithmetic mean exposure to both electric and magnetic fields (P<0.05). Duration of employment was strongly associated with an increased risk of leukemia. Those who had worked for at least 20 years, and were in the highest tertiles of percentage of time spent above 10 and 20 V/m had odds ratios of 10.17 (95% CI = 1.58-65.30) and 8.23 (95% CI = 1. 24-54.43), respectively, when compared to those in the lowest tertile. Nonsignificant elevations in risk were observed between indices of magnetic fields and leukemia. CONCLUSIONS: Our results support the hypothesis that electric fields act as a promoting agent in the etiology of adult leukemia. Exposure assessment based on alternate indices of electric and magnetic fields should be incorporated into future occupational studies of cancer.
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Campos Electromagnéticos/efectos adversos , Leucemia/etiología , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Leucemia/epidemiología , Masculino , Enfermedades Profesionales/epidemiología , Ontario , Medición de RiesgoRESUMEN
The relationship between alcohol, tobacco and coffee consumption and pancreatic cancer was investigated using population-based case-control data obtained from eight Canadian provinces. Our findings are based on analyses performed on 583 histologically confirmed pancreatic cancer cases and 4813 controls. Questionnaire data were obtained directly from 76% of the cases. Male subjects with 35 or more cigarette pack-years had an increased risk of developing pancreatic cancer relative to never smokers (OR= 1.46, 95% CI 1.00-2.14). Similarly, women reporting at least 23 cigarette pack-years of smoking had an odds ratio of 1.84 (95% CI 1.25-2.69). For the most part, consumption of total alcohol, wine, liquor and beer was not associated with pancreatic cancer. Coffee drinking was not related to pancreatic cancer. More work is needed to clarify the role of these and other potentially modifiable risk factors as a means to reduce the incidence of this disease for which treatment results remain disappointing.
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Consumo de Bebidas Alcohólicas/efectos adversos , Café/efectos adversos , Neoplasias Pancreáticas/etiología , Fumar/efectos adversos , Adulto , Anciano , Canadá/epidemiología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/epidemiología , Vigilancia de la Población , Medición de RiesgoRESUMEN
OBJECTIVES: To evaluate the relationship between prostate cancer and several potential lifestyle risk factors. METHODS: We analyzed data obtained from a population-based case-control study conducted in eight Canadian provinces. Risk estimates were generated by applying multivariate logistic regression methods to 1623 histologically confirmed prostate cancer cases and 1623 male controls aged 50-74. RESULTS: Cases were more likely to have a first-degree relative with a history of cancer, particularly prostate cancer (OR = 3.1, 95% CI = 1.8-5.4). Reduced risks of prostate cancer were observed among those of Indian descent (OR = 0.2, 95% CI = 0.1-0.5) or any Asian descent (OR = 0.3, 95% CI = 0.2-0.6) relative to those of western European descent. Total fat consumption, tomato and energy intake, were not associated with prostate cancer. The risk of prostate cancer was inversely related to the number of cigarettes smoked daily (p = 0.06) and cigarette pack-years (p < 0.01), while no association was observed between the total number of smoking years or the number of years since smoking cessation. Anthropometric measures and moderate and strenuous levels of leisure time physical activity were not strongly related to prostate cancer. In contrast, strenuous occupational activities at younger ages appeared protective. CONCLUSIONS: Our analyses are limited by the absence of data related to tumor severity and screening history. Further studies are needed to investigate the relationship between behavioral risk factors and prostate cancer screening practices.
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Estilo de Vida , Neoplasias de la Próstata/etiología , Anciano , Canadá , Estudios de Casos y Controles , Etnicidad , Humanos , Masculino , Persona de Mediana Edad , Salud Laboral , Neoplasias de la Próstata/epidemiología , Factores de Riesgo , Fumar/efectos adversosRESUMEN
OBJECTIVES: To evaluate the risk of childhood leukemia in relation to residential electric and magnetic field (EMF) exposures. METHODS: A case control study based on 88 cases and 133 controls used different assessment methods to determine EMF exposure in the child's current residence. Cases comprised incident leukemias diagnosed at 0-14 years of age between 1985-1993 from a larger study in southern Ontario; population controls were individually matched to the cases by age and sex. Exposure was measured by a personal monitoring device worn by the child during usual activities at home, by point-in-time measurements in three rooms and according to wire code assigned to the child's residence. RESULTS: An association between magnetic field exposures as measured with the personal monitor and increased risk of leukemia was observed. The risk was more pronounced for those children diagnosed at less than 6 years of age and those with acute lymphoblastic leukemia. Risk estimates associated with magnetic fields tended to increase after adjusting for power consumption and potential confounders with significant odds ratios (OR) (OR: 4.5, 95% confidence interval (CI): 1.3-15.9) observed for exposures > or = 0.14 microTesla (microT). For the most part point-in-time measurements of magnetic fields were associated with non-significant elevations in risk which were generally compatible with previous research. Residential proximity to power lines having a high current configuration was not associated with increased risk of leukemia. Exposures to electric fields as measured by personal monitoring were associated with a decreased leukemia risk. CONCLUSIONS: The findings relating to magnetic field exposures directly measured by personal monitoring support an association with the risk of childhood leukemia. As exposure assessment is refined, the possible role of magnetic fields in the etiology of childhood leukemia becomes more evident.