The association between obesity, other cardiovascular risk factors, and cognitive function in a Canadian First Nations population was investigated using a cross‐sectional design. Eligible individuals were aged ≥18 years, without a history of stroke, nonpregnant, with First Nations status, and who had undergone cognitive function assessment by the Clock Drawing Test (CDT) and Trail Making Test Parts A and B. Parts A and B were combined into an Executive Function Score (TMT‐exec). Hypertension, a previous history of cardiovascular disease, dyslipidemia, metabolic syndrome, insulin resistance, and the presence and duration of diabetes were examined in addition to obesity. In the case of TMT‐exec only, obese individuals were at an approximately fourfold increased risk for lowered cognitive performance compared to those who were not obese in multivariable models (odds ratio (OR): 3.77, 95% confidence interval (CI): 1.46–9.72) whereas there was no effect for overweight individuals compared to those with a normal weight in unadjusted analysis. Those having an increased waist circumference also had 5 times the risk compared to those without an increased waist circumference (OR: 5.41, 95% CI: 1.83–15.99). Adjusted for age, sex, and insulin resistance, individuals having the metabolic syndrome were at an approximately fourfold increased risk compared to those without the metabolic syndrome (OR: 3.67, 95% CI: 1.34–10.07). No other cardiovascular risk factors were associated. Obesity and metabolic syndrome were associated with lowered cognitive performance. These results highlight the importance of studying the health effects of obesity beyond traditional disease endpoints, even in a relatively youthful population.

raumatic brain injury (TBI) is a leading cause of death and disability worldwide. It is a very serious and often overlooked health care issue. Victims are often young, and survivors of TBI often live with devastating consequences, including temporary or permanent impairments, partial or total functional disability, psychosocial maladjustments and associated economic burdens. 1 Even mild injuries can have long-term consequences. 2 An examination of coroners' files in Ontario showed that approximately half of all workplace fatalities involved a brain injury. 3 In a study by Kim et al. 4 based on severe injuries identified from the Ontario Trauma Registry, it was found that hospitalizations involving workrelated traumatic brain injuries increased by 12.4% from 1993 to 2001. Information obtained from the Workplace Safety and Insurance Board (WSIB) of Ontario revealed that the number of occupational TBI claims has nearly doubled over a span of eight years. 5 Previous studies have examined severe/fatal 3,4 or mild cases separately. 6 To date, no recent study has investigated occupational TBI across levels of severity. Because of the number of negative repercussions associated with occupational TBI and the apparent rise in its occurrence, a comprehensive examination of occupational TBI across levels of severity is needed in the Canadian context. Additionally, men continue to represent the majority of fatal and seriously injured, 3,4 therefore we hypothesize that men will display a more detrimental profile of occupational TBIs than women. Thus the objectives of this study were to provide an overview of occupational TBIs that includes factors associated with the injury, the implication being that the results may assist in better targeting the prevention of work-related TBI, such as through sex-specific prevention. METHODSA case series design was used to examine all WSIB claims with an injury date in the year 2004 and categorized by the WSIB as either "intracranial injury" or "concussion". All fatalities categorized as "traumatic" were also examined, for evidence of traumatic brain injury. The WSIB data are based on approximately 70% of the total Ontario workforce and were abstracted using a form that drew upon Haddon's Matrix. 7 In total, just over 1,500 non-fatal claim files were examined. Of those claims, 1,006 qualified as TBIs. Only claims with a confirmed

Breast cancers classified by estrogen receptor (ER) and/or progesterone receptor (PR) expression have different clinical, pathologic, and molecular features. We examined existing evidence from the epidemiologic literature as to whether breast cancers stratified by hormone receptor status are also etiologically distinct diseases. Despite limited statistical power and nonstandardized receptor assays, in aggregate, the critically evaluated studies (n = 31) suggest that the etiology of hormone receptor–defined breast cancers may be heterogeneous. Reproduction-related exposures tended to be associated with increased risk of ER-positive but not ER-negative tumors. Nulliparity and delayed childbearing were more consistently associated with increased cancer risk for ER-positive than ER-negative tumors, and early menarche was more consistently associated with ER-positive/PR-positive than ER-negative/PR-negative tumors. Postmenopausal obesity was also more consistently associated with increased risk of hormone receptor–positive than hormone receptor–negative tumors, possibly reflecting increased estrogen synthesis in adipose stores and greater bioavailability. Published data are insufficient to suggest that exogenous estrogen use (oral contraceptives or hormone replacement therapy) increase risk of hormone-sensitive tumors. Risks associated with breast-feeding, alcohol consumption, cigarette smoking, family history of breast cancer, or premenopausal obesity did not differ by receptor status. Large population-based studies of determinants of hormone receptor–defined breast cancers defined using state-of-the-art quantitative immunostaining methods are needed to clarify the role of ER/PR expression in breast cancer etiology.

In conclusion, the beneficial effect of CHM in CHF is by reducing mortality and hospitalizations combined. Care in the home in CHF seems to be more effective and less costly compared with UC.

Medical record review (MRR) is often used in clinical research and evaluation, yet there is limited literature regarding best practices in conducting a MRR, and there are few studies reporting interrater reliability (IRR) from MRR data. The aim of this research was twofold: (a) to develop a MRR abstraction tool and standardize the MRR process and (b) to examine the IRR from MRR data. This study introduces the MRR-Conduction Model, which was used to implement a MRR, and examines the IRR between two abstractors who collected preinjury medical and psychiatric, incident-related medical and postinjury head symptom information from the medical records of 47 neurologically injured workers. Results showed that the percentage agreement was > or =85% and the unweighted kappa statistic was > or =.60 for most variables, indicating substantial IRR. An effective and reliable MRR to abstract medical-related information requires planning and time. The MRR-Conduction Model is proposed to guide the process of creating a MRR.

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Immunohistochemical characterization of tumor tissues in epidemiological studies is a promising approach to identify breast cancer subtypes with distinct etiology. The recent development of the tissue microarray (TMA) technique allows for standardized, rapid, and cost-effective immunohistochemical characterization of many cases, which is critical in epidemiological studies. Sectioning paraffin blocks at different times results in loss of material, which can be reduced by preparing many sections each time a block is cut. However, data suggest that staining intensity declines in whole sections prepared from conventional paraffin blocks with storage time, resulting in false-negative results. This problem would be accentuated in TMAs because of the limited tissue representation of each case. To evaluate this concern, we prepared a single TMA block from 125 invasive breast carcinomas collected in a population-based case-control study conducted in Poland and compared estrogen receptor (ER-α), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression in sections cut and stored for 6 months at room temperature with sections cut from the same TMA block and stained on the same day. Percentage of positive cases for stored versus fresh sections was similar for ER (59.0%) but significantly higher in fresh sections for PR (56.3% versus 64.1%, P = 0.01) and HER2 (45.5% versus 64.4%, P < 0.001). Among cases positive in both stored and fresh sections, the median percentage of immunoreactive cells was significantly reduced and the staining intensity was consistently lower in stored compared with fresh sections. We conclude that loss of immunoreactivity is an important problem in TMAs of breast cancer. Improved methods for sectioning TMAs and storing tissue sections aimed at reducing loss of immunoreactivity are critical for the use of TMAs in epidemiological studies.

Background: We investigated the associations among cardiovascular risk factors, carotid atherosclerosis and cognitive function in a Canadian First Nations population. Methods: Individuals aged ≥18 years, without stroke, nonpreg- nant and with First Nations status were assessed by the Trail Making Test Parts A and B. Results were combined into a Trail Making Test executive function score (TMT-exec). Doppler ultrasonography assessed carotid stenosis and plaque volume. Anthropometric, vascular and metabolic risk factors were assessed by interview, clinical examinations and blood tests. Results: For 190 individuals with TMT-exec scores, the median age of the population was 39 years. Compared to the reference group, individuals with elevated levels of left carotid stenosis (LCS) and total carotid stenosis (TCS) were less likely to demonstrate lowered cognitive performance [LCS, odds ratio (OR): 0.47, 95% confidence interval (CI): 0.24–0.96; TCS, OR: 0.40, 95% CI: 0.20–0.80]. No effect was shown for plaque volume. In structural equation modeling, we found that for every 1-unit change in the anthropometric factor in kg/m², there was a 0.86-fold decrease in the percent of TCS (p < 0.05). Conclusions: Individuals with elevated levels of LCS and TCS were less likely to demonstrate lowered performance. There was some suggestion that TCS mediates the effect of anthropometric risk factors on cognitive function.