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Radiation exposure has long been a concern for the public, policy makers, and health researchers. Beginning with radar during World War II, human exposure to radio-frequency radiation1 (RFR) technologies has grown substantially over time. In 2011, the International Agency for Research on Cancer (IARC) reviewed the published literature and categorized RFR as a “possible” (Group 2B) human carcinogen. A broad range of adverse human health effects associated with RFR have been reported since the IARC review. In addition, three large-scale carcinogenicity studies in rodents exposed to levels of RFR that mimic lifetime human exposures have shown significantly increased rates of Schwannomas and malignant gliomas, as well as chromosomal DNA damage. Of particular concern are the effects of RFR exposure on the developing brain in children. Compared with an adult male, a cell phone held against the head of a child exposes deeper brain structures to greater radiation doses per unit volume, and the young, thin skull's bone marrow absorbs a roughly 10-fold higher local dose. Experimental and observational studies also suggest that men who keep cell phones in their trouser pockets have significantly lower sperm counts and significantly impaired sperm motility and morphology, including mitochondrial DNA damage. Based on the accumulated evidence, we recommend that IARC re-evaluate its 2011 classification of the human carcinogenicity of RFR, and that WHO complete a systematic review of multiple other health effects such as sperm damage. In the interim, current knowledge provides justification for governments, public health authorities, and physicians/allied health professionals to warn the population that having a cell phone next to the body is harmful, and to support measures to reduce all exposures to RFR.

ispartof: INTERNATIONAL JOURNAL OF OCCUPATIONAL MEDICINE AND ENVIRONMENTAL HEALTH vol:31 issue:6 pages:837-839 ispartof: location:Poland status: published

BACKGROUND Evidence for a role of dietary risk factors in the cause of breast cancer has been inconsistent. The evaluation of overall dietary patterns instead of foods in isolation may better reflect the nature of true dietary exposure in a population. OBJECTIVE We used 2 cohort studies to identify and confirm associations between dietary patterns and breast cancer risk. DESIGN Dietary patterns were derived by using a principal components factor analysis in 1097 breast cancer cases and an age-stratified subcohort of 3320 women sampled from 39,532 female participants in the Canadian Study of Diet, Lifestyle and Health (CSDLH). We conducted a confirmatory factor analysis in 49,410 subjects in the National Breast Screening Study (NBSS) in whom 3659 cases of incident breast cancer developed. Cox regression models were used to estimate HRs for the association between derived dietary factors and risk of breast cancer in both cohorts. RESULTS The following 3 dietary factors were identified from the CSDLH: healthy, ethnic, and meat and potatoes. In the CSDLH, the healthy dietary pattern was associated with reduced risk of breast cancer (HR for high compared with low quintiles: 0.73; 95% CI: 0.58, 0.91; P-trend = 0.001), and the meat and potatoes dietary pattern was associated with increased risk in postmenopausal women only (HR for high compared with low quintiles: 1.26; 95% CI: 0.92, 1.73; P-trend = 0.043). In the NBSS, the association between the meat and potatoes pattern and postmenopausal breast cancer risk was confirmed (HR: 1.31; 95% CI: 0.98, 1.76; P-trend = 0.043), but there was no association between the healthy pattern and risk of breast cancer. CONCLUSION Adherence to a plant-based diet that limits red meat intake may be associated with reduced risk of breast cancer, particularly in postmenopausal women.

The silicate mineral asbestos is categorized into two main groups based on fiber structure: serpentine asbestos (chrysotile) and amphibole asbestos (crocidolite, amosite, anthophyllite, tremolite, and actinolite). Chrysotile is used in more than 2 000 applications and is especially prevalent in the construction industry. Although its use is banned or restricted in more than 52 countries, an estimated 107 000 workers die from asbestos exposure each year, and approximately 125 million workers continue to be exposed. Furthermore, ambient exposures persist to which the public is exposed, globally. Today, the primary controversies regarding the use of asbestos are the potencies of different types of asbestos, as opposed whether or not asbestos causes morbidity and mortality. The asbestos industry has promoted and funded research based on selected literature, ignoring both clinical and scientific knowledge. In this piece, we highlight a prominent example of a conflicted publication that sought to undermine the World Health Organization (WHO) campaign to stop the use of all forms of asbestos, including chrysotile asbestos. Independent and rigorous scientific data provide sufficient evidence that chrysotile asbestos, like other forms of asbestos, is a cause of asbestos-related morbidity and premature mortality.

With 5.9 billion reported users, mobile phones constitute a new, ubiquitous and rapidly growing exposure worldwide. Mobile phones are two-way microwave radios that also emit low levels of electromagnetic radiation. Inconsistent results have been published on potential risks of brain tumors tied with mobile phone use as a result of important methodological differences in study design and statistical power. Some studies have examined mobile phone users for periods of time that are too short to detect an increased risk of brain cancer, while others have misclassified exposures by placing those with exposures to microwave radiation from cordless phones in the control group, or failing to attribute such exposures in the cases. In 2011, the World Health Organization, International Agency for Research on Cancer (IARC) advised that electromagnetic radiation from mobile phone and other wireless devices constitutes a "possible human carcinogen," 2B. Recent analyses not considered in the IARC review that take into account these methodological shortcomings from a number of authors find that brain tumor risk is significantly elevated for those who have used mobile phones for at least a decade. Studies carried out in Sweden indicate that those who begin using either cordless or mobile phones regularly before age 20 have greater than a fourfold increased risk of ipsilateral glioma. Given that treatment for a single case of brain cancer can cost between $100,000 for radiation therapy alone and up to $1 million depending on drug costs, resources to address this illness are already in short supply and not universally available in either developing or developed countries. Significant additional shortages in oncology services are expected at the current growth of cancer. No other environmental carcinogen has produced evidence of an increased risk in just one decade. Empirical data have shown a difference in the dielectric properties of tissues as a function of age, mostly due to the higher water content in children's tissues. High resolution computerized models based on human imaging data suggest that children are indeed more susceptible to the effects of EMF exposure at microwave frequencies. If the increased brain cancer risk found in young users in these recent studies does apply at the global level, the gap between supply and demand for oncology services will continue to widen. Many nations, phone manufacturers, and expert groups, advise prevention in light of these concerns by taking the simple precaution of "distance" to minimize exposures to the brain and body. We note than brain cancer is the proverbial "tip of the iceberg"; the rest of the body is also showing effects other than cancers.

Pulp and paper mills use a variety of chemical substances potentially hazardous to human health. Compounds of both short- and long-term toxicological significance are found in workplaces, air emissions, and water effluent. In this paper we evaluate the body of published literature on cancer associated with working in pulp and paper mills as well as in surrounding communities. Multiple comparisons, questionable statistical power, and the absence of individual exposure assessments have resulted in non-corroborative findings over the years. However, a new generation of study sophistication, international in scale and coordinated by the International Agency for Research on Cancer (IARC), has catalogued tens of thousands of exposure measurements made at a large number of work stations within the pulp and paper industry, allowing for greatly improved individual-level exposure assessments. This approach reduces non-differential misclassification of exposure, increasing the power of these studies to detect exposure disease relationships, especially for rarer cancers. While the ability to associate specific chemical exposures with cancer outcomes in the large IARC multinational cohort may yet help to resolve the status of some of the many chemicals not currently classifiable as to their carcinogenicity by IARC, this effort has, to date, not added significantly to knowledge. Of the three studies they have published to date, one involved a well-established carcinogen (asbestos) and another involved a mixture containing probable carcinogens (volatile organochlorines). While the asbestos study is somewhat unremarkable for finding an association with pleural cancer in the expected direction, the volatile organochlorine study may be most notable for failing to find an association between volatile organochlorine exposure and liver cancer, non-Hodgkin's lymphoma, or esophageal cancer, as some previous studies had found. Nonetheless, given the known hazards and the potential for both environmental and human exposure by any of a number of pathways, vigilance on the part of governments for regulation and for ongoing workplace and environmental monitoring remains a health imperative.

Comment on ‘Estimating the asbestos-related lung cancer burden from mesothelioma mortality’ – IARC and Chrysotile Risks

All asbestos types cause asbestosis (cancer): chrysotile is not biopersistent, so fibre analysis is not diagnostic http://ow.ly/BOLC30grqYg

Obesity, physical inactivity, and sedentary behavior, concomitants of the modern environment, are potentially modifiable breast cancer risk factors. This study investigated the association of anthropometric measurements, physical activity and sedentary behavior, with the risk of incident, invasive breast cancer using a prospective cohort of women enrolled in the Canadian Study of Diet, Lifestyle and Health. Using a case-cohort design, an age-stratified subcohort of 3,320 women was created from 39,532 female participants who returned completed self-administered lifestyle and dietary questionnaires at baseline. A total of 1,097 incident breast cancer cases were identified from the entire cohort via linkage to the Canadian Cancer Registry. Cox regression models, modified to account for the case-cohort design, were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for the association between anthropometric characteristics, physical activity, and the risk of breast cancer. Weight gain as an adult was positively associated with risk of post-menopausal breast cancer, with a 6 % increase in risk for every 5 kg gained since age 20 (HR 1.06; 95 % CI 1.01–1.11). Women who exercised more than 30.9 metabolic equivalent task (MET) hours per week had a 21 % decreased risk of breast cancer compared to women who exercised less than 3 MET hours per week (HR 0.79; 95 % CI 0.62–1.00), most evident in pre-menopausal women (HR 0.62; 95 % CI 0.43–0.90). As obesity reaches epidemic proportions and sedentary lifestyles have become more prevalent in modern populations, programs targeting adult weight gain and promoting physical activity may be beneficial with respect to reducing breast cancer morbidity.

Background Tobacco use has been implicated in the etiology of a large number of cancers, and there exists substantial biological plausibility that it could also be involved in breast carcinogenesis. Despite this, epidemiological evidence to date is inconsistent. The aim of this study was to investigate the role of active smoking and the risk of incident, invasive breast cancer using a prospective cohort of women from the Canadian Study of Diet, Lifestyle and Health. Methods Using a case-cohort design, an age-stratified subcohort of 3314 women was created from 39,532 female participants who returned completed self-administered lifestyle and dietary questionnaires at baseline. A total of 1096 breast cancer cases were identified in the entire cohort (including 141 cases from the subcohort) by linkage to the Canadian Cancer Registry. Cox regression models were used to estimate hazard ratios for the association between the different smoking exposures and the risk of breast cancer, using a modification for the case-cohort design. Results After carefully considering early-life exposures and potential confounders, we found no association between any smoking exposure and risk of breast cancer in this study (Hazard ratio = 1.00, 95% confidence interval = 0.87–1.17 for ever vs never smokers). Conclusions Although these results cannot rule out an association between smoking and breast cancer, they do agree with the current literature suggesting that, if an association does exist, it is relatively weak.

To identify patients at high risk of functional dependence and examine the progression of disability after a hip fracture.This was a population-based prospective inception cohort study of all patients aged 65+ yr who fractured a hip between July 1996 and August 1997. Demographic, socioeconomic, social support, and health status information was assessed in the hospital and 3 mo postfracture.The analysis included 367 patients. Almost all patients with cognitive impairment were functionally dependent postfracture, with new disabilities frequently occurring in transferring. Among patients of high mental status, increased risk of functional dependence was associated with advanced age, more co-morbidities, hip pain, poor self-rated health, and previous employment in a prestigeous occupation. Bathing disability was most likely in those who functioned independently prefracture; a disability in dressing was most common otherwise.Hip pain is amenable to treatment and may improve chances of functional recovery. Patients can be assisted in regaining prefracture function if they are targeted for rehabilitation on the basis of mental status. The focus should be on bathing and dressing among patients of high cognition and transferring among those patients with mental impairment.

Background Health care workers (HCW) have historically borne a heavy burden of tuberculosis (TB) infection and disease. Unfortunately, physicians are rarely included in HCW surveys of tuberculin exposure and infection. Methods The prevalence and risk factors for tuberculin reactivity were determined for a sample of the 1732 licensed physicians in Edmonton. Stratified random sampling was used to select 554 specialists and 219 general practitioners. These physicians were contacted by means of an introductory letter and a follow-up telephone call to solicit participation. All eligible physicians were asked to complete a questionnaire and those with either no recorded positive tuberculin test or a previously negative result were two-step tuberculin skin tested. Results In total, 560 physicians (72.4 %) participated in the study. The overall tuberculin reactivity for this population was 45.9%. Using logistic regression analysis, we determined that risk factors for reactivity were aged over 45 years, of foreignbirth, previous Bacillus Calmette-Guerin (BCG) vaccination, foreign practice experience, and being a respiratory medicine specialist. Conclusion The prevalence of tuberculin reactivity among physicians is considerably higher than estimates for the general Canadian population. This observed excess risk may be associated with factors linked to their medical practice. The high participation rate suggests physician willingness to participate in this type of research, and emphasizes the need to include them in routine HCW surveillance.

OBJECTIVE: To determine whether surgical subspecialty training in colorectal surgery or frequency of rectal cancer resection by the surgeon are independent prognostic factors for local recurrence (LR) and survival. SUMMARY BACKGROUND DATA: Variation in patient outcome in rectal cancer has been shown among centers and among individual surgeons. However, the prognostic importance of surgeon-related factors is largely unknown. METHODS: All patients undergoing potentially curative low anterior resection or abdominoperineal resection for primary adenocarcinoma of the rectum between 1983 and 1990 at the five Edmonton general hospitals were reviewed in a historic-prospective study design. Preoperative, intraoperative, pathologic, adjuvant therapy, and outcome variables were obtained. Outcomes of interest included LR and disease-specific survival (DSS). To determine survival rates and to control both confounding and interaction, multivariate analysis was performed using Cox proportional hazards regression. RESULTS: The study included 683 patients involving 52 surgeons, with > 5-year follow-up obtained on 663 (97%) patients. There were five colorectal-trained surgeons who performed 109 (16%) of the operations. Independent of surgeon training, 323 operations (47%) were done by surgeons performing < 21 rectal cancer resections over the study period. Multivariate analysis showed that the risk of LR was increased in patients of both noncolorectal trained surgeons (hazard ratio (HR) = 2.5, p = 0.001) and those of surgeons performing < 21 resections (HR = 1.8, p < 0.001). Stage (p < 0.001), use of adjuvant therapy (p = 0.002), rectal perforation or tumor spill (p < 0.001), and vascular/neural invasion (p = 0.002) also were significant prognostic factors for LR. Similarly, decreased disease-specific survival was found to be independently associated with noncolorectal-trained surgeons (HR = 1.5, p = 0.03) and surgeons performing < 21 resections (HR = 1.4, p = 0.005). Stage (p < 0.001), grade (p = 0.02), age (p = 0.02), rectal perforation or tumor spill (p < 0.001), and vascular or neural invasion (p < 0.001) were other significant prognostic factors for DSS. CONCLUSION: Outcome is improved with both colorectal surgical subspecialty training and a higher frequency of rectal cancer surgery. Therefore, the surgical treatment of rectal cancer patients should rely exclusively on surgeons with such training or surgeons with more experience.

BACKGROUND: An outbreak of invasive meningococcal disease (IMD) in metro Edmonton, Alberta, Canada between December 1999 and June 2002 resulted in 84 laboratory-confirmed cases. Most cases were infected with Neisseria meningitidis serogroup C, and the highest age-specific incidence was observed in the 15–19 year age group. METHODS: A case-control study was conducted to identify modifiable IMD risk factors among outbreak cases. Two controls were matched to each case on age and sex, and were recruited through random-digit dialing. A questionnaire was telephone-administered to 132 study participants (44 cases, 88 controls). Conditional logistic regression was utilized to calculate risk measures. RESULTS: Multivariate analysis revealed three statistically significant risk factors: bar patronage (OR 35.2; 95% CI: 2.64–468), “rave” attendance (OR 12.8; 95% CI: 1.47–111) and maternal smoking (OR 8.88; 95% CI: 1.67–47.4). Humidifier use in the home was protective (OR 0.07; 95% CI: 0.009–0.64). CONCLUSION: While the precision of risk estimates was low in the multivariate model, this study has identified rave attendance as an emergent IMD risk factor.

Bacillus Calmette-Guerin (BCG) vaccination against tuberculosis has been used around the world for 60 years, yet its efficacy in large, controlled prospective studies is inconsistent. The factors influencing BCG protection include variation in immunogenic potential, background exposure to environmental mycobacteria, and differences in host response to vaccine. As a means of addressing regional differences in protection, case-control studies provide a relatively inexpensive, rapid means of assessing regional vaccine effects. Treaty Indian cases (n = 160) resident in Alberta, Canada, presenting during a 5-year period (1975-1979) were individually matched for age, sex, and Band with two nontuberculous controls. A 57 percent protection by BCG vaccination was demonstrated. These results support the usefulness of case-control studies and their importance in planning tuberculosis control programs.

OBJECTIVE: To describe the demographics and estimate the prevalence of hepatitis C virus (HCV) in a cohort of Human Immunodeficiency Virus (HIV) positive patients in Northern Alberta. METHODS: A cross-sectional (prevalence) study was performed on a cohort of HIV-positive patients. HCV testing was not widely available until December 1989, and the more sensitive, second generation immunoassay was not available until 1992. To reduce the effect of testing bias, we restricted consideration of HCV status to patients first seen January 1, 1992 onward. RESULTS: Forty-four percent of patients in the whole cohort were tested for HCV (564/1,276) and 62% (505/809) of patients entered since January 1, 1992 were tested for HCV. During the period January 1, 1992-December 31, 1999, the prevalence of HCV in our cohort of northern Alberta HIV-positive patients was at least 37.9% (307/809) and was 60.8% (307/505) among those who were tested for HCV in 1992 or later. The mean age of the coinfected group was 33.6 years, 66.1% were male, 91.2% were injection drug users (IDUs), 56.8% were Caucasian, and 40.0% were Aboriginal. A statistically significant difference was found between the HCV-negative cohort, the HCV co-infected cohort, and the HCVuntested cohort for the following variables: risk behaviour, gender, ethnic status, death, occurrence of an AIDS-defining illness (p

OBJECTIVES. The purpose of this study was to compare hip fracture hospitalization rates between a fluoridated and a non-fluoridated community in Alberta, Canada: Edmonton, which has had fluoridated drinking water since 1967, and Calgary, which considered fluoridation in 1991 but is currently revising this decision. METHODS. Case subjects were all individuals aged 45 years or older residing in Edmonton or Calgary who were admitted to hospitals in Alberta between January 1, 1981, and December 31, 1987, and who had a discharge diagnosis of hip fracture. Edmonton rates were compared with Calgary rates, with adjustment for age and sex using the Edmonton population as a standard. RESULTS. The hip fracture hospitalization rate for Edmonton from 1981 through 1987 was 2.77 per 1000 person-years. The age-sex standardized rate for Calgary was 2.78 per 1000 person-years. No statistically significant difference was observed in the overall rate, and only minor differences were observed within age and sex subgroups, with the Edmonton rates being higher in males. CONCLUSIONS. These findings suggest that fluoridation of drinking water has no impact, neither beneficial nor deleterious, on the risk of hip fracture.

A case-referent study, designed to test associations between asbestos, nickel, and the development of laryngeal cancer, was conducted in southern Ontario in 1977-1979. The cases were individually matched to neighborhood referents for gender and age. This constituted the primary study. Personal interviews had secured tobacco, alcohol, and detailed work histories. To 183 of the male pairs was added retrospective assessments of sulfuric acid exposure for each job, blind of disease status; this constituted the data base for an augmented secondary analysis. Logistic regression revealed statistically significant odds ratios when tobacco and alcohol were controlled. Exposure-response gradients were strongly positive with odds ratios in the range of 1.97 [95% confidence interval (95% CI) 0.63-6.13] for short duration-low level exposure through 6.91 [95% CI 2.20-21.74] for long duration-higher level exposure employing progressively more specific definitions of exposure. Asbestos as a confounder and the interaction terms examined were nonsignificant. These findings are corroborative of those of other studies.

The effect of different summary measures of worklife exposure on the estimation of risk is reported. Two matched case-referent studies associating sulfuric acid exposure and cancer from Baton Rouge and southern Ontario were used. Five summary exposure measures were converted to discrete levels of exposure through the selection of equivalent percentile points on each measure's respective percentage frequency distribution for logistic regression modeling purposes. The southern Ontario data set exhibited only minor differences across all five exposure measures. The Baton Rouge data set, however, produced different results, and the time-dependent measures appeared to underestimate risk. It is possible, therefore, to obtain different estimates of risk depending on the exposure measure selected. It is recommended that, in the absence of proved models for assessing exposure, a variety of summary measures be used to estimate risk. This approach would facilitate the comparison of findings across studies.

To improve our understanding of physician reluctance to participate in randomized clinical trials, we examined physician responses to the regulation of obtaining written informed consent. Between June 1984 and February 1985 a purposive sample of 170 breast cancer specialists from eight countries completed a self-administered questionnaire and follow-up interview. The sample included 90 medical oncologists, 65 surgeons, and 29 radiotherapists. Responses to individual questions are presented in three global categories: (1) physician role--physicians believed that their view of their professional "self" was not compatible with informed consent regulations; (2) physician autonomy--physicians perceived a loss of individual decision-making power and an increase in professional accountability; and (3) physician-patient relationship--physicians stated that informed consent regulations influenced what they told trial patients and affected the ensuing doctor-patient relationship. Respondents developed complex methods to accommodate the incongruities they perceived between their view of their professional self and the need to obtain informed consent.

As part of a prospective study in Toronto, Canada of male sexual contacts of men with either acquired immunodeficiency syndrome (AIDS) or an AIDS-related condition (primary cases), separate interviews were conducted in 1984-1985 with primary cases and their corresponding sexual contacts. Seventy-five primary cases and their corresponding sexual contacts were asked details concerning the sexual activities involved in their sexual encounters. Spearman correlation coefficients were calculated for the responses regarding frequency of various sexual activities between the primary case and his corresponding contact. Comparison of responses revealed good to excellent correlations for the majority of the sexual activities. Regression analysis of responses (dependent variable = contact's response; independent variable = primary's response) revealed the tendency for primary cases to report greater numbers of various activities than sexual contacts, as illustrated by regression coefficients that were consistently less than unity. Agreement between primary responses and sexual contact responses appeared to be affected by the time lapsed from the last sexual encounter with the contact and the date of the primary case's interview. No effect on agreement was observed when primary case diagnosis and the total number of other sexual partners of primary cases were considered. The authors conclude that such data can be captured with sufficient reliability and validity for use in epidemiologic investigations to assess the risk of acquisition of human immunodeficiency virus for the more common forms of sexual activity. However, some caution may be necessary in interpreting the results for some activities (anal digit insertion, anilingus) since agreement is less satisfactory for these activities.

We studied the reasons surgical principal investigators chose not to enter patients in a large, multicenter trial sponsored by a cooperative group. In 1976 the National Surgical Adjuvant Project for Breast and Bowel Cancers (NSABP) initiated a clinical trial to compare segmental mastectomy and postoperative radiation, or segmental mastectomy alone, with total mastectomy. Because the low rates of accrual were threatening to close the trial prematurely, we mailed a questionnaire to the 94 NSABP principal investigators, asking why they were not entering eligible patients in the trial. A response rate of 97 per cent was achieved. Physicians who did not enter all eligible patients offered the following explanations: (1) concern that the doctor-patient relationship would be affected by a randomized clinical trial (73 per cent), (2) difficulty with informed consent (38 per cent), (3) dislike of open discussions involving uncertainty (22 per cent), (4) perceived conflict between the roles of scientist and clinician (18 per cent), (5) practical difficulties in following procedures (9 per cent), and (6) feelings of personal responsibility if the treatments were found to be unequal (8 per cent). Further investigation into the behavioral aspects of the investigator-patient relationship is particularly pressing, since fear of change in this relationship was the most common reason given for not entering eligible patients in the trial.

Workers on an ethanol unit which used sulfuric acid in strong concentrations at a large refinery and chemical plant in Baton Rouge, Louisiana were reported, in 1979, at excess risk for upper respiratory cancer. The carcinogen implicated by indirect evidence was diethyl sulfate. However, with the continued use of sulfuric acid in the same plant, and with additional cases not attributable to the ethanol process, the hypothesis of an association between sulfuric acid exposure and upper respiratory cancer was tested. Each of 50 confirmed cases of upper respiratory cancer diagnosed between 1944 and 1980, was matched to at least three controls on sex, race, age, date of initial employment, and duration of employment. Thirty-four of the 50 cases were laryngeal cancers. Data were obtained from existing plant records. Retrospective estimates of exposure were made without regard to case or control status. Findings from conditional logistic regression techniques were supported by other statistical methods. Among workers classified as potentially highly exposed, four-fold relative risks for all upper respiratory cancer sites combined were exceeded by the relative risk for laryngeal cancer specifically. Exposure-response and consistency across various comparisons after controlling statistically for tobacco-use, alcoholism and other previously implicated risk factors, suggest increased cancer risk with higher exposure.

Excerpt To the editor: Metroka and associates (1) have reported a syndrome resembling the acquired immunodeficiency syndrome among wives of bisexual men who do not use intravenous drugs, do not hav...

A total of 246 healthy male sexual contacts of men with either acquired immunodeficiency syndrome (AIDS) or an AIDS-related condition were recruited into a prospective study in Toronto, Canada between July 1984 and July 1985. At induction, data were collected on the sexual relationship between the contact and his primary case, sexual activities with other men, history of sexually transmitted diseases and other diseases, and use of recreational drugs. At recruitment, 144 sexual contacts had antibodies to human immunodeficiency virus (HIV); 102 of the contacts were seronegative at induction and at three months following recruitment. No association between HIV seropositivity and total number of sexual partners could be demonstrated. In univariate and multivariate analyses, receptive and insertive anal intercourse with the primary cases, and activities which either indicated or potentially caused anorectal mucosal injury (rectal douching, perianal bleeding, receipt of objects in ano, and receptive fisting) were strongly associated with HIV seropositivity. In the final multiple logistic regression model, two significant interaction effects were observed: the interaction between receptive anal intercourse and insertive anal intercourse and that between receptive anal intercourse and the anorectal mucosal injury index. These two interaction terms had negative regression coefficients which suggested that change in one sexual activity would not decrementally reduce risk of HIV infection without a comparable modification in the other activity. No association could be demonstrated between oral-genital and oral-anal sexual contact and odds ratios for these sexual activities declined to levels below 1.0 when adjusted for frequency of receptive anal intercourse.

OBJECTIVES: To identify determinants of mortality and institutionalization after hip fracture and to identify those older hip fracture patients at high risk of death or institutionalization after hip fracture. DESIGN: Population-based prospective inception cohort study of hip fracture patients; patients were assessed in the hospital and at 3 months following the hip fracture. SETTING: Edmonton area hip fracture patients admitted to one of two Edmonton, Alberta, Canada, acute care centers between July 10, 1996, and August 31, 1997. PARTICIPANTS: Patients were residents of the Edmonton area and over the age of 64. Those who had previously fractured the same hip within the past 5 years or had some pathological condition underlying the hip fracture were excluded. Of 610 eligible patients, 558 contributed some, baseline information and were included in the mortality analysis; the institutionalization analysis was restricted to the 338 patients who lived in the community before fracture, survived the 3-month period postfracture, and had completed a 3-month follow-up interview. MEASUREMENTS: The baseline interview was done in the hospital to assess mental status, prefracture physical function, prefracture health perception, and prefracture social support. The 3-month follow-up interview was done by phone to assess physical function, health perception, and social support 3 months postfracture. Demographic and comorbidity information was collected from medical records. RESULTS: Low mental status in hospital was found to increase the chances of mortality and institutionalization, and male gender was found to increase mortality risk fourfold. Each additional 10 years of age increased the risk of institutionalization approximately 2.5 times. Patients with lower postfracture physical function had at least five times the risk of institutionalization compared to patients with high postfracture physical function. CONCLUSIONS: Cognitive impairment, older age, and gender were associated with increased risk of poor outcome following hip fracture. The socioeconomic variables — social support and health perception — did not contribute significant additional information in explaining mortality or institutionalization risk. While demographic factors cannot be modified, physical function 3 months postfracture may be amenable to intervention and may reduce the risk of institutionalization. Intervening to increase postfracture physical function may be particularly beneficial to older patients, or to those who are cognitively impaired. J Am Geriatr Soc 48: 283–288, 2000.