Circulatory system disease mortality and occupational exposure to radon progeny in the cohort of Newfoundland Fluorspar Miners between 1950 and 2016.

OBJECTIVES: Exposure to ionizing radiation may increase the risk of circulatory diseases, including heart disease. A limited number of cohort studies of underground miners have investigated these associations. We previously reported a positive but non-statistically significant association between radon progeny and heart disease in a cohort of Newfoundland fluorspar miners. In this study, we report updated findings that incorporate 15 additional years of follow-up. METHODS: The cohort included 2050 miners who worked in the fluorspar mines from 1933 to 1978. Statistics Canada linked the personal identifying data of the miners to Canadian mortality data to identify deaths from 1950 to 2016. We used previously derived individual-level estimates of annual radon progeny exposure in working-level months. Cumulative exposure was categorized into quantiles. We estimated relative risks and their 95% confidence intervals using Poisson regression for deaths from circulatory, ischemic heart disease and acute myocardial infarction. Relative risks were adjusted for attained age, calendar year, and the average number of cigarettes smoked daily. RESULTS: Relative to the Newfoundland male population, the standardized mortality ratio for circulatory disease in this cohort was 0.82 (95% CI 0.74-0.91). Those in the highest quantile of cumulative radon progeny exposure had a relative risk of circulatory disease mortality of 1.03 (95% CI 0.76-1.40) compared to those in the lowest quantile. The corresponding estimates for ischemic disease and acute myocardial infarction were 0.99 (95% CI 0.66-1.48), and 1.39 (95% CI 0.84-2.30), respectively. CONCLUSIONS: Our findings do not support the hypothesis that occupational exposure to radon progeny increases the risk of circulatory disease.

Barriers to oral care: a cross-sectional analysis of the Canadian longitudinal study on aging (CLSA).

BACKGROUND: Oral health plays a role in overall health, indicating the need to identify barriers to accessing oral care. The objective of this study was to identify barriers to accessing oral health care and examine the association between socioeconomic, psychosocial, and physical measures with access to oral health care among older Canadians. METHODS: A cross-sectional study was conducted using data from the Canadian Longitudinal Study on Aging (CLSA) follow-up 1 survey to analyze dental insurance and last oral health care visit. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between socioeconomic, psychosocial, and physical measures with access to oral care, measured by dental insurance and last oral health visit. RESULTS: Among the 44,011 adults included in the study, 40% reported not having dental insurance while 15% had not visited an oral health professional in the previous 12 months. Several factors were identified as barriers to accessing oral health care including, no dental insurance, low household income, rural residence, and having no natural teeth. People with an annual income of <$50,000 were four times more likely to not have dental insurance (adjusted OR: 4.09; 95% CI: 3.80-4.39) and three times more likely to report not visiting an oral health professional in the previous 12 months (adjusted OR: 3.07; 95% CI: 2.74-3.44) compared to those with annual income greater than $100,000. CONCLUSIONS: Identifying barriers to oral health care is important when developing public health strategies to improve access, however, further research is needed to identify the mechanisms as to why these barriers exist.

Evaluating the utility of self-reported questionnaire data to screen for dysglycemia in young adults: Findings from the US National Health and Nutrition Examination Survey.

Dysglycemia, including prediabetes and type 2 diabetes, is dangerous and widespread. Yet, the condition is transiently reversible and sequelae preventable, prompting the use of prediction algorithms to quickly assess dysglycemia status through self-reported data. However, as current algorithms have largely been developed in older populations, their application to younger adults is uncertain considering associations between risk factors and dysglycemia vary by age. We sought to identify sex-specific predictors of current dysglycemia among young adults and evaluate their ability to screen for prediabetes and undiagnosed diabetes. We analyzed 2005-2014 data from the National Health and Nutrition Examination Survey for 3251 participants aged 20-39, who completed an oral glucose tolerance test (OGTT), had not been diagnosed with diabetes, and, for females, were not pregnant. Sex-specific stepwise logistic models were fit with predictors identified from univariate analyses. Risk scores were developed using adjusted odds ratios and model performance was assessed using area under the curve (AUC) measures. The OGTT identified 906 (27.9%) and 78 (2.4%) participants with prediabetes or undiagnosed diabetes, respectively. Predictors of dysglycemia status for males were BMI, age, race, and first-degree family history of diabetes, and, in addition to those, education, delivered baby weight, waist circumference, and vigorous physical activity for females. Our male- and female-specific models demonstrated improved validity to assess dysglycemia presence among young adults relative to the widely-used American Diabetes Association test (AUC = 0.69 vs. 0.61; 0.92 vs. 0.71, respectively). Thus, age-specific scoring algorithms employing questionnaire data show promise and are effective in identifying dysglycemia among young adults.

Association of urinary sodium and potassium excretion with blood pressure.

BACKGROUND: Higher levels of sodium intake are reported to be associated with higher blood pressure. Whether this relationship varies according to levels of sodium or potassium intake and in different populations is unknown. METHODS: We studied 102,216 adults from 18 countries. Estimates of 24-hour sodium and potassium excretion were made from a single fasting morning urine specimen and were used as surrogates for intake. We assessed the relationship between electrolyte excretion and blood pressure, as measured with an automated device. RESULTS: Regression analyses showed increments of 2.11 mm Hg in systolic blood pressure and 0.78 mm Hg in diastolic blood pressure for each 1-g increment in estimated sodium excretion. The slope of this association was steeper with higher sodium intake (an increment of 2.58 mm Hg in systolic blood pressure per gram for sodium excretion >5 g per day, 1.74 mm Hg per gram for 3 to 5 g per day, and 0.74 mm Hg per gram for <3 g per day; P<0.001 for interaction). The slope of association was steeper for persons with hypertension (2.49 mm Hg per gram) than for those without hypertension (1.30 mm Hg per gram, P<0.001 for interaction) and was steeper with increased age (2.97 mm Hg per gram at >55 years of age, 2.43 mm Hg per gram at 45 to 55 years of age, and 1.96 mm Hg per gram at <45 years of age; P<0.001 for interaction). Potassium excretion was inversely associated with systolic blood pressure, with a steeper slope of association for persons with hypertension than for those without it (P<0.001) and a steeper slope with increased age (P<0.001). CONCLUSIONS: In this study, the association of estimated intake of sodium and potassium, as determined from measurements of excretion of these cations, with blood pressure was nonlinear and was most pronounced in persons consuming high-sodium diets, persons with hypertension, and older persons. (Funded by the Heart and Stroke Foundation of Ontario and others.).

Macronutrient intake and stomach cancer.

PURPOSE: This study examines the association between intake of selected macronutrients and the risk of stomach cancer in a Northern American population. METHODS: Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces by 1,181 incident, histologically confirmed cases of stomach cancer and 5,039 population controls. Information on nutrient intake was obtained using a food frequency questionnaire. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived through unconditional logistic regression to adjust for potential confounders, including an estimate of total energy intake. RESULTS: Intakes of total fat, saturated fat, and cholesterol were significantly associated with the risk of stomach cancer: The ORs for the highest versus the lowest quartile were 1.58 (95% CI 1.13-2.20), 1.86 (95% CI 1.37-2.52), and 1.75 (95% CI 1.36-2.25), respectively. Total fiber was inversely associated with stomach cancer (p = 0.03). The positive associations with intake of total fat and saturated fat were apparently stronger in women, overweight or obese subjects, and ever smokers. Saturated fat was specifically associated with increased risk of gastric cardia cancer, with an OR of 3.31 (95% CI 1.48-7.43). CONCLUSIONS: A diet high in saturated fat appears to increase the risk of stomach cancer, particularly among obese subjects and for gastric cardia cancer.

Updated Analysis of Radon Exposure and Lung Cancer Mortality in the Cohort of Newfoundland Fluorspar Miners (1950-2016).

The commercial mining of fluorspar in St. Lawrence Newfoundland began in 1933. Miners who worked underground were exposed to high levels of radon progeny, especially before ventilation was introduced into the mines in 1960. The mean cumulative radon exposure for underground miners in this cohort was 380.9 working level months (WLM). A series of studies of this cohort have characterized the increased risks of lung cancer mortality due to radon. We have extended the follow-up of this cohort an additional 15 years to provide additional insights on the risks of low levels of radon exposure, and the modifying effects of time since exposure, age at first exposure, attained age, duration of exposure, and cigarette smoking. The cohort consisted of 1,735 underground and 315 male surface miners who, combined, accrued 81,650 person-years of follow-up. The mortality experience of the cohort was determined from 1950-2016 through record linkage to Canadian national death data. Individual-level estimates of exposure to radon progeny, in WLMs, were determined for each year of employment. We compared the mortality experience of the underground miners to Newfoundland men using the standardized mortality ratio (SMR). Poisson regression models were fit to estimate excess relative risks (ERR) per 100 WLM. There were 236 lung cancer deaths identified, and of these, 221 occurred among underground workers. The SMR for lung cancer among underground miners compared to Newfoundland men was 2.67 (95% CI: 2.33, 3.04). The ERR per 100 WLM for lung cancer mortality, assuming a 5-year exposure lag, was 0.41 (95% CI: 0.23, 0.59). Attained age and time since exposure were important modifiers to the radon-lung cancer relationship. The joint relationship between smoking and radon on lung cancer risk was sub-additive, however, the smoking data were limited and available for only half of the cohort.

Prevalence estimates of chronic kidney disease in Canada: results of a nationally representative survey.

BACKGROUND: Chronic kidney disease is an important risk factor for death and cardiovascular-related morbidity, but estimates to date of its prevalence in Canada have generally been extrapolated from the prevalence of end-stage renal disease. We used direct measures of kidney function collected from a nationally representative survey population to estimate the prevalence of chronic kidney disease among Canadian adults. METHODS: We examined data for 3689 adult participants of cycle 1 of the Canadian Health Measures Survey (2007-2009) for the presence of chronic kidney disease. We also calculated the age-standardized prevalence of cardiovascular risk factors by chronic kidney disease group. We cross-tabulated the estimated glomerular filtration rate (eGFR) with albuminuria status. RESULTS: The prevalence of chronic kidney disease during the period 2007-2009 was 12.5%, representing about 3 million Canadian adults. The estimated prevalence of stage 3-5 disease was 3.1% (0.73 million adults) and albuminuria 10.3% (2.4 million adults). The prevalence of diabetes, hypertension and hypertriglyceridemia were all significantly higher among adults with chronic kidney disease than among those without it. The prevalence of albuminuria was high, even among those whose eGFR was 90 mL/min per 1.73 m(2) or greater (10.1%) and those without diabetes or hypertension (9.3%). Awareness of kidney dysfunction among adults with stage 3-5 chronic kidney disease was low (12.0%). INTERPRETATION: The prevalence of kidney dysfunction was substantial in the survey population, including individuals without hypertension or diabetes, conditions most likely to prompt screening for kidney dysfunction. These findings highlight the potential for missed opportunities for early intervention and secondary prevention of chronic kidney disease.

Human papillomavirus infection and the association with abnormal Pap findings in Yukon, Canada.

OBJECTIVE: Certain types of the human papillomavirus (HPV) are highly associated with cervical cancer or dysplasia, but its prevalence is largely unknown in northern Canada where there is significant aboriginal representation and unique barriers to accessing care. This study determined the prevalence of HPV infection and its association with cervical cancer precursor lesions in Yukon, Canada. MATERIALS AND METHODS: This was a cross-sectional study of 1,542 women attending routine Pap smear screening in 14 communities in Yukon, from February 2009 to June 2010. Type-specific HPV infection was detected by an in-house Luminex assay. Cervical Pap cytology was evaluated by pathologists blinded to HPV test results. RESULTS: The overall HPV prevalence rate in Yukon women was higher than those reported in some Canadian provinces and other countries. Human papillomavirus infection prevalence rates were 24.5% for any type, 18.4% for high-risk types, 6.2% for HPV types 16 or 18, 6.7% for HPV α-7 species, and 10.6% for HPV α-9 species. Human papillomavirus infection was strongly associated with single marital status or having 2 or more sexual partners in the past year. Human papillomavirus infection (overall, high-risk types, HPV-16/18, α-7, or α-9 species) was strongly associated with Pap cytological abnormalities (adjusted odds ratios ranged from 8.4 to 44.2). CONCLUSIONS: As in other areas of northern Canada, HPV prevalence for high-risk types and α-7 species is high among women in the Yukon. Sexual behavioral factors strongly influence HPV prevalence rates. The findings may have implications for HPV vaccination and health promotion programs in northern regions.

Oral Health Problems among Canadians Aged 45 to 85: Data from the Canadian Longitudinal Study on Aging Baseline Survey (2011-2015).

Oral health is a critical component of overall health. The objective of this study was to describe oral health problems among 47,581 adults aged 45 to 85 in the Canadian Longitudinal Study on Aging (CLSA) among those who have at least one natural tooth (92%) and those without natural teeth across various demographic categories. Among the 47,581 participants in the study, 92% reported having at least one natural tooth (dentate). Among those without teeth, 63% reported an income less than CAD 50,000 versus 39% among those with teeth. Whether they had teeth or not, over 30% of people reported two or more oral health problems. Older adults appear to be retaining their natural teeth (28.9%), but still report experiencing oral health problems. As the population ages, loss of all teeth may not be the most useful proxy for poor oral health, and a population-level understanding of oral health problems may help to better define poor oral health.

Canadian breast implant cohort: extended follow-up of cancer incidence.

Cosmetic breast implants are not associated with increased breast cancer incidence, but variations of risk according to implant characteristics are still poorly understood. As well, the assessment of cancer risk for sites other than breast needs to be clarified. The purpose of this study was to fill these research gaps. This study presents an extended analysis of 10 more years of follow-up of a large Canadian cohort of women who received either cosmetic breast implants (n = 24,558) or other cosmetic surgery (15,893). Over 70% of the implant cohort was followed for over 20 years. Cancer incidence among implant women was compared to those of controls using multivariate Poisson models and the general female population using the standardized incidence ratios (SIRs). Women with breast implants had reduced rates of breast and endometrial cancers compared to other surgery women. Subglandular implants were associated to a reduced rate of breast cancer compared to submuscular implants [incidence rate ratio (IRR) = 0.78, 95% confidence interval (CI) = 0.63-0.96] and this reduction persisted over time. We observed a sevenfold increased rate (IRR = 7.36, 95% CI = 1.86-29.12) of breast cancer in the first 5 years after the date of surgery for polyurethane-coated subglandular implant women but this IRR decreased progressively over time (p value for trend = 0.02). We also observed no increased risk of rarer forms of cancer among augmented women. A reduction in breast cancer incidence was observed for women with subglandular implants relative to women with submuscular implants. Possible increase of breast cancer incidence shortly after breast augmentation with polyurethane implants needs to be verified.

Long-term association between leisure-time physical activity and changes in happiness: analysis of the Prospective National Population Health Survey.

Happiness is among the most fundamental of all human goals. Although the short-term association between physical activity and happiness is well known, the long-term associations are not. Data from the National Population Health Survey cycles conducted between 1994/1995 and 2008/2009 (cycles 1 through 8) were analyzed. Happy respondents were classified as physically active or inactive at baseline and then were followed up in subsequent cycles to examine their likelihood of becoming unhappy. Individuals who changed their activity level also were examined. After controlling for potential confounding factors, the authors found that leisure-time physical activity (LTPA) was associated with reduced odds of unhappiness after 2 years and 4 years. People who were inactive in 2 consecutive cycles were more than twice as likely to be unhappy as those who remained active in both cycles after 2 years. Compared with those who became active, inactive participants who remained inactive were also more likely to become unhappy. A change in LTPA from active to inactive was associated with increased odds of becoming unhappy 2 years later. This study suggests that LTPA has a long-term association with happiness. Changes in LTPA are associated with subsequent mood status.

Increasing blood pressure and its associated factors in Canadian children and adolescents from the Canadian Health Measures Survey.

BACKGROUND: Canada is facing a childhood obesity epidemic. Elevated blood pressure (BP) is a major complication of obesity. Reports on the impact of excess adiposity on BP in children and adolescents have varied significantly across studies. We evaluated the independent effects of obesity, physical activity, family history of hypertension, and socioeconomic status on BP in a nationally representative sample of children and adolescents. METHODS: We analysed cross-sectional data for 1850 children aged 6 to 17 years who participated in the Canadian Health Measures Survey, Cycle 1, 2007-2009. Systolic BP (SBP) and diastolic BP (DBP) were age-, sex-, and height-adjusted to z-scores (SBPZ and DBPZ). Body mass index (BMI) z-scores were calculated based on World Health Organization growth standards. Multivariate linear regression was used to evaluate the independent effects of relevant variables on SBPZ and DBPZ. RESULTS: For most age/sex groups, obesity was positively associated with SBP. Being obese was associated with higher DBP in adolescent boys only. The BP effect of obesity showed earlier in young girls than boys. Obese adolescents were estimated to have an average 7.6 mmHg higher SBP than normal weight adolescents. BMI had the strongest effect on BP among obese children and adolescents. Moderately active adolescent boys had higher SBP (3.9 mmHg) and DBP (4.9 mmHg) than physically active boys. Family history of hypertension showed effects on SBP and DBP in younger girls and adolescent boys. Both family income and parent education demonstrated independent associations with BP in young children. CONCLUSIONS: Our findings demonstrate the early impact of excess adiposity, insufficient physical activity, family history of hypertension, and socioeconomic inequalities on BP. Early interventions to reduce childhood obesity can, among other things, reduce exposure to prolonged BP elevation and the future risk of cardiovascular disease.

Migration and diabetes in British Columbia and Quebec: prevalence and health service utilization.

OBJECTIVES: This study describes prevalence of diabetes among immigrants and health service utilization among diabetic immigrants in British Columbia (BC) and Quebec (QC). METHODS: Immigrants to BC and QC between 1985 and 1999 were identified. Using age-standardized rate ratios, they were compared with a matched comparison group with respect to their diabetes prevalence and, among those with diabetes, physician service utilization. RESULTS: Immigrant women in both provinces and men in BC had higher rates of diabetes compared to the matched comparison group. Rates varied by region of birth and language ability. Diabetes prevalence rate ratios increased with length of stay in BC. Diabetic immigrants had lower rates of physician visits than diabetic comparisons. This gap decreased commensurate with immigrants' length of stay in BC. Diabetic immigrants who spoke neither official language had similar or higher rates of physician visits compared with immigrants who spoke one or both official languages. CONCLUSIONS: Genetic predisposition, lifestyle changes, acculturation, resettlement stress and differential health care access may explain increased prevalence of diabetes among many immigrants. These results can inform diabetes prevention and management programs tailored to the needs of specific immigrant groups. The gap in health service use between diabetic immigrants and comparisons does not appear to be related to language ability. Further studies are required to identify reasons.

Antioxidants and breast cancer risk- a population-based case-control study in Canada.

BACKGROUND: The effect of antioxidants on breast cancer is still controversial. Our objective was to assess the association between antioxidants and breast cancer risk in a large population-based case-control study. METHODS: The study population included 2,362 cases with pathologically confirmed incident breast cancer (866 premenopausal and 1,496 postmenopausal) and 2,462 controls in Canada. Intakes of antioxidants from diet and from supplementation as well as other potential risk factors for breast cancer were collected by a self-reported questionnaire. RESULTS: Compared with subjects with no supplementation, 10 years or longer supplementation of zinc had multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI) of 0.46 (0.25-0.85) for premenopausal women, while supplementation of 10 years or longer of multiple vitamin, beta-carotene, vitamin C, vitamin E and zinc had multivariable-adjusted ORs (95% CIs) of 0.74 (0.59, 0.92), 0.58 (0.36, 0.95), 0.79 (0.63-0.99), 0.75 (0.58, 0.97), and 0.47 (0.28-0.78), respectively, for postmenopausal women. No significant effect of antioxidants from dietary sources (including beta-carotene, alpha-carotene, lycopene, lutein and zeaxanthin, vitamin C, vitamin E, selenium and zinc) or from supplementation less than 10 years was observed. CONCLUSIONS: This study suggests that supplementation of zinc in premenopausal women, and supplementation of multiple vitamin, beta-carotene, vitamin C, vitamin E and zinc in postmenopausal women for 10 or more years may protect women from developing breast cancer. However, we were unable to determine the overall effect of total dose or intake from both diet and supplement.

Physical activity and hematologic cancer prevention.

This chapter presents the epidemiologic evidence on the association between physical activity and hematologic cancers and related hypothesized biologic mechanisms. Some preliminary indications of a protective role for physical activity for non-Hodgkin's lymphoma, leukemia, multiple myeloma, and Hodgkin's lymphoma exist, but the level of epidemiologic evidence is still insufficient to make any definitive conclusions regarding the nature of these associations. Several plausible biologic mechanisms underlying the possible associations between physical activity and hematologic cancers have been proposed, including enhancement of immune function, reduction in obesity, improvement of antioxidant defense systems, impact on metabolic hormones, and anti-inflammatory effects. Future studies should improve the estimation of physical activity by using more reliable, valid, and comprehensive measurement tools, assessing all components of physical activity (type, intensity, and time period), and conducting intervention studies to evaluate the effect of physical activity on various biomarkers of cancer in order to provide further insight into plausible biologic mechanisms underlying the possible association between physical activity and hematologic cancers.

Plasma vitamin D levels and risk of metabolic syndrome in Canadians.

PURPOSE: Vitamin D deficiency has been implicated in susceptibility to the development of metabolic syndrome, obesity and type 2 diabetes mellitus. The present study aimed to quantify the association between vitamin D plasma level, the number of metabolic syndrome components and insulin resistance in Canadians. METHODS: Vitamin D plasma level and clinical data were determined from 1,818 subjects from the Canadian Health Measures Survey; a representative health survey of the general population of Canada conducted from 2007 to 2009. The definition of metabolic syndrome was based on the National Cholesterol Education Program, Adult Treatment Panel III criteria. Adjusted general linear models were used to estimate the association between vitamin D level and probability of having metabolic syndrome, as well as the association between plasma vitamin D and insulin resistance (homeostasis model assessment for insulin resistance, or HOMA-IR). RESULTS: The prevalence of metabolic syndrome in the study population was 8.9%. The number of metabolic syndrome components was inversely correlated with plasma vitamin D level (ρ= -0.1, p < 0.0001). Subjects in the highest vitamin D quartile had lower odds ratio of metabolic syndrome compared with their counterparts in the lowest vitamin D quartile (0.50, 95% CI= 0.24-1.06). Increasing plasma vitamin D level (by 10 nmol/L) was inversely associated with HOMA-IR score (ß= -0.08, p=0.006) in a model adjusted for physical activity, smoking status, month of interview, age, sex and ethnicity. CONCLUSION: Vitamin D plasma levels are associated with the occurrence of metabolic syndrome components and insulin resistance among Canadians and are linked to increased level of insulin resistance.

Determinants of delays in treatment initiation in children and adolescents diagnosed with leukemia or lymphoma in Canada.

Minimizing delays that may occur along the cancer care pathway requires an understanding of their determinants. Few studies on childhood cancers have been published on the factors that influence the time it takes for patients to get a first medical consultation (patient delay) and treatment (health care system [HCS] delay) once cancer symptoms have been recognized. Our objective was to assess factors related to disease, patient and HCS on patient and HCS delay for children and adolescents with leukemias and lymphomas in Canada. A prospective cohort study was conducted on subjects enrolled in the Treatment and Outcomes Surveillance program of the Canadian Childhood Cancer Surveillance and Control Program, a national surveillance program. We studied 963 leukemia and 397 lymphoma patients who were less than 19-years old at diagnosis in 1995-2000. Logistic regression models were used to measure the associations between candidate predictive factors and delays. Age was positively associated with patient delay for both leukemia and lymphoma patients, but not with HCS delay. Patients first seen in a hospital emergency room had a lower risk of HCS delay than patients first seen by a general practitioner. Cancer subtype was associated with patient delay for leukemia patients, and HCS delay for lymphoma patients. Longer patient delay was associated with a lower risk of long HCS delay for both cancers. Factors related to the patients, their disease and the HCS may exert different influences on varying segments of the care pathway of leukemia and lymphoma patients.

Could recent decreases in breast cancer incidence really be due to lower HRT use? Trends in attributable risk for modifiable breast cancer risk factors in Canadian women.

OBJECTIVES: Recent downward trends in breast cancer incidence have been attributed to declining use of hormone replacement therapy (HRT). To determine whether this is a credible conclusion, this study calculated population attributable risk (PAR) for HRT and other modifiable breast cancer risk factors. METHODS: PAR calculation needs both the prevalence of a risk factor, and the relative risk (RR) for breast cancer incidence for that risk factor. Prevalences were calculated for Canadian women, aged 50-69, participating in the National Population Health Survey, 1994-2006. RR were derived from published research: 1.4 for HRT use, 1.4 for excessive alcohol use, 1.15 for physical inactivity, 1.25 for smoking, 1.4 for BMI over 30 kg/m2. Trends for PAR were calculated for the risk factors separately, as well as combined. Age-adjusted breast cancer incidence rates were calculated for Canadian women aged 50-69 for the years 1994-2004. RESULTS: Between 1998 and 2004, PAR for HRT decreased by 50%. PAR for other risk factors showed only small changes, and the combined PAR decreased by 18.6%. Age-adjusted breast cancer incidence for women aged 50-69 peaked in 2000 at 330.0/100,000, then dropped by 17.2% by 2004. CONCLUSION: Patterns of PAR for HRT use in Canada are consistent with the noticeable decrease in breast cancer incidence observed for women of the same age group. Combining PAR for all risk factors indicated that changes in HRT use overpowered any trends of other risk factors. The combined PAR suggest that alterations in lifestyle could have considerable impact on breast cancer incidence.

Longitudinal associations between bullying and alcohol use and binge drinking among grade 9 and 10 students in the COMPASS study.

OBJECTIVES: Adolescents involved in bullying are at increased risk for alcohol use; however, much of this research has been cross-sectional. The aim of this work was to therefore examine the longitudinal associations between bullying and future alcohol use. METHODS: Data were drawn from the COMPASS study. The current study used a 2-year linked sample of grade 9 and 10 students from 2015 to 2017 (n = 6005). Students were asked to report their involvement with bullying as well as alcohol use and binge drinking behaviours. Generalized estimating equations regression analyses were used to examine the relationship between bullying involvement at baseline and alcohol use and binge drinking at follow-up. RESULTS: Overall, 20% of students in grades 9 and 10 reported involvement in bullying. There was evidence of a modest longitudinal association between bullying and binge drinking. Being a bully or bully-victim at baseline was associated with increased odds of initiating future binge drinking. CONCLUSIONS: Being a bully or bully-victim in grade 9 or 10 was associated with initiating binge drinking within the following 2 years. Targeted alcohol use prevention programming may benefit these groups.

RéSUMé: OBJECTIFS: Les adolescents impliqués dans l'intimidation courent un risque accru de consommation d'alcool. Cependant, une grande partie de cette recherche a été transversale. Cette étude vise à examiner les associations longitudinales entre l'intimidation et la consommation future d'alcool. MéTHODES: Les données provenaient de l'étude COMPASS. La présente étude utilise un échantillon d'élèves de 9e et 10e années qui ont été suivi de 2015 à 2017 (n = 6 005). Les élèves ont été invités à signaler leur implication dans l'intimidation, la consommation d'alcool et la consommation excessive d'alcool. Des modèles d'équations d'estimation généralisées ont servi à examiner la relation entre la participation à l'intimidation au départ, et la consommation d'alcool et la consommation excessive d'alcool occasionnelle dans les deux années suivantes. RéSULTATS: 20 % des élèves de 9e et 10e années ont déclaré avoir été victimes d'intimidation. Il y avait des preuves d'une modeste association longitudinale entre l'intimidation et la consommation excessive d'alcool. Être un intimidateur ou une victime d'intimidation au départ était associé à une probabilité accrue de consommation excessive d'alcool occasionnelle par la suite. CONCLUSION: Être un intimidateur ou victime d'intimidation était associé à une consommation excessive d'alcool occasionnelle deux ans plus tard chez les élèves de la 9e et la 10e année. Des programmes ciblés de prévention de la consommation d'alcool pourraient bénéficier à ces groupes.