An assessment of antimicrobial resistant disease threats in Canada.

BACKGROUND: Antimicrobial resistance (AMR) of infectious agents is a growing concern for public health organizations. Given the complexity of this issue and how widespread the problem has become, resources are often insufficient to address all concerns, thus prioritization of AMR pathogens is essential for the optimal allocation of risk management attention. Since the epidemiology of AMR pathogens differs between countries, country-specific assessments are important for the determination of national priorities. OBJECTIVE: To develop a systematic and transparent approach to AMR risk prioritization in Canada. METHODS: Relevant AMR pathogens in Canada were selected through a transparent multi-step consensus process (n=32). Each pathogen was assessed using ten criteria: incidence, mortality, case-fatality, communicability, treatability, clinical impact, public/political attention, ten-year projection of incidence, economic impact, and preventability. For each pathogen, each criterion was assigned a numerical score of 0, 1, or 2, and multiplied by criteria-specific weighting determined through researcher consensus of importance. The scores for each AMR pathogen were summed and ranked by total score, where a higher score indicated greater importance. A sensitivity analysis was conducted to determine the effects of changing the criteria-specific weights. RESULTS: The AMR pathogen with the highest total weighted score was extended spectrum B-lactamase-producing (ESBL) Enterobacteriaceae (score=77). When grouped by percentile, ESBL Enterobacteriaceae, Clostridium difficile, carbapenem-resistant Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus were in the 80-100th percentile. CONCLUSION: This assessment provides useful information for prioritising public health strategies regarding AMR resistance at the national level in Canada. As the AMR environment and challenges change over time and space, this systematic and transparent approach can be adapted for use by other stakeholders domestically and internationally. Given the complexity of influences, resource availability and multiple stakeholders, regular consideration of AMR activities in the public health realm is essential for appropriate and responsible prioritisation of risk management that optimises the health and security of the population.

Estimating sensitivity of laboratory testing for influenza in Canada through modelling.

BACKGROUND: The weekly proportion of laboratory tests that are positive for influenza is used in public health surveillance systems to identify periods of influenza activity. We aimed to estimate the sensitivity of influenza testing in Canada based on results of a national respiratory virus surveillance system. METHODS AND FINDINGS: The weekly number of influenza-negative tests from 1999 to 2006 was modelled as a function of laboratory-confirmed positive tests for influenza, respiratory syncytial virus (RSV), adenovirus and parainfluenza viruses, seasonality, and trend using Poisson regression. Sensitivity was calculated as the number of influenza positive tests divided by the number of influenza positive tests plus the model-estimated number of false negative tests. The sensitivity of influenza testing was estimated to be 33% (95%CI 32-34%), varying from 30-40% depending on the season and region. CONCLUSIONS: The estimated sensitivity of influenza tests reported to this national laboratory surveillance system is considerably less than reported test characteristics for most laboratory tests. A number of factors may explain this difference, including sample quality and specimen procurement issues as well as test characteristics. Improved diagnosis would permit better estimation of the burden of influenza.

Health outcomes of low-dose ionizing radiation exposure among medical workers: a cohort study of the Canadian national dose registry of radiation workers.

BACKGROUND: Medical workers can be exposed to low-dose ionizing radiation from various sources. The potential cancer risks associated with ionizing radiation exposure have been derived from cohort studies of Japanese atomic bomb survivors who had experienced acute, high-level exposure. Since such extrapolations are subject to uncertainty, direct information is needed on the risk associated with chronic low-dose occupational exposure to ionizing radiation. OBJECTIVES: To determine the occupational doses of ionizing radiation and examine possible associations with mortality rates and cancer incidence in a cohort of medical workers deriving from the National Dose Registry of Canada (NDR) over the period of 1951-1987. METHODS: Standardized mortality and incidence ratios (SMR and SIR, respectively) were ascertained by linking NDR data for a cohort of 67 562 medical workers (23 580 males and 43 982 females) with the data maintained by the Canadian Mortality, and Cancer Incidence databases. Dosimetry information was obtained from the National Dosimetry Services. RESULTS: During the follow-up period, 1309 incident cases of cancer (509 in males, 800 in females) and 1325 deaths (823 in males, 502 in females) were observed. Mortality from cancer and non-cancer causes was generally below expected as compared to the general Canadian population. Thyroid cancer incidence was significantly elevated both among males and females, with a combined SIR of 1.74 and 90% CI: 1.40-2.10. CONCLUSIONS: The findings confirm previous reports on an increased risk of the thyroid cancer among medical workers occupationally exposed to ionizing radiation. Over the last 50 years, radiation protection measures have been effective in reducing radiation exposures of medical workers to the current very low levels.

Developing integrative primary healthcare delivery: adding a chiropractor to the team.

BACKGROUND: The use of complementary and alternative medicine has been increasing in Canada despite the lack of coverage under the universal public health insurance system. Physicians and other healthcare practitioners are now being placed in multidisciplinary teams, yet little research on integration exists. OBJECTIVE: We sought to investigate the effect of integrating chiropractic on the attitudes of providers on two healthcare teams. DESIGN: A mixed methods design with both quantitative and qualitative components was used to assess the healthcare teams. Assessment occurred prior to integration, at midstudy, and at the end of the study (18 months). SETTING: Multidisciplinary healthcare teams at two community health centers in Ottawa, Ontario, participated in the study. PATIENTS/PARTICIPANTS: All physicians, nurse practitioners, and degree-trained nurses employed at two study sites were approached to take part in the study. INTERVENTION: A chiropractor was introduced into each of the two healthcare teams. MAIN OUTCOME MEASURES: A quantitative questionnaire assessed providers' opinions, experiences with collaboration, and perceptions of chiropractic care. Focus groups were used to encourage providers to communicate their experiences and perceptions of the integration and of chiropractic. RESULTS: Twelve providers were followed for the full 18 months of integration. The providers expressed increased willingness to trust the chiropractors in shared care (F value = 7.18; P = .004). Questions regarding the legitimacy (F value = 12.33; P < .001) and effectiveness (F value = 11.17; P < .001) of chiropractic became increasingly positive by study end. CONCLUSION: This project has demonstrated the successful integration of chiropractors into primary healthcare teams.

Chiropractic care of musculoskeletal disorders in a unique population within Canadian community health centers.

OBJECTIVE: This study was part of a larger demonstration project integrating chiropractic care into publicly funded Canadian community health centers. This pre/post study investigated the effectiveness of chiropractic care in reducing pain and disability as well as improving general health status in a unique population of urban, low-income, and multiethnic patients with musculoskeletal (MSK) complaints. METHODS: All patients who presented to one of two community health center-based chiropractic clinics with MSK complaints between August 2004 and December 2005 were recruited to participate in this study. Outcomes were assessed by a general health measure (Short Form-12), a pain scale (VAS), and site-specific disability indexes (Roland-Morris Questionnaire and Neck Disability Index), which were administered before and after a 12-week treatment period. RESULTS: Three hundred twenty-four patients with MSK conditions were recruited into the study, and 259 (80.0%) of them were followed to the study's conclusion. Clinically important and statistically significant positive changes were observed for all outcomes (Short Form-12: physical composite score mean change = 4.9, 95% confidence interval [CI] = 3.8-6.0; VAS: current pain mean change = 2.3, 95% CI = 1.9-2.6; Neck Disability Index: mean change = 6.8, 95% CI = 5.4-8.1; Roland-Morris Questionnaire: mean change = 4.3, 95% CI = 3.6-5.1). No adverse events were reported. CONCLUSIONS: Patients of low socioeconomic status face barriers to accessing chiropractic services. This study suggests that chiropractic care reduces pain and disability as well as improves general health status in patients with MSK conditions. Further studies using a more robust methodology are needed to investigate the efficacy and cost-effectiveness of introducing chiropractic care into publicly funded health care facilities.

Epidemiology of testicular cancer: an overview.

Testicular cancer is a rare disease, accounting for 1.1% of all malignant neoplasms in Canadian males. Despite the low overall incidence of testicular cancer, it is the most common malignancy among young men. The incidence rate of testicular cancer has been increasing since the middle of the 20th century in many western countries. However, the etiology of testicular cancer is not well understood. A search of the peer-reviewed literature was conducted to identify important articles for review and inclusion in this overview of the epidemiology of testicular cancer. Most of the established risk factors are related to early life events, including cryptorchidism, carcinoma in situ and in utero exposure to estrogens. Occupational, lifestyle, socioeconomic and other risk factors have demonstrated mixed associations with testicular cancer. Although there are few established risk factors for testicular cancer, some appear to be related to hormonal balance at various life stages. Lifestyle and occupational exposures occurring later in life may play a role in promoting the disease, although they are not likely involved in cancer initiation. In addition to summarizing the current epidemiologic evidence on risk factors for testicular cancer, we suggest future research directions that may elucidate the etiology of testicular cancer.

Decreases in occupational exposure to ionizing radiation among Canadian dental workers.

OBJECTIVE: To describe doses of ionizing radiation and their possible associations with mortality rates and cancer incidence among Canadian dental workers. METHODS: The National Dose Registry (NDR) of Canada was used to assess occupational dose of ionizing radiation received by dental workers. The NDR cohort includes 42,175 people classified as dental workers. Subjects in the NDR were linked to both the Canadian Mortality Database and the Canadian Cancer Database to ascertain cause of death and cancer incidence, respectively. RESULTS: The cohort consisted of 9,051 male and 33,124 female dental workers. A total of 656 incident cases of cancer and 558 deaths were observed. The standardized mortality ratio associated with all-cause mortality was 0.53 (90% confidence interval [CI] 0.49-0.57). The incidence of cancer among dental workers was lower than that for the Canadian population for all cancers except melanoma of the skin (for melanoma, the standardized incidence ratio was 1.46 [90% CI 1.14-1.85]). Occupational doses of ionizing radiation among dentists and dental workers have decreased markedly since the 1950s. CONCLUSIONS: Dental workers receive very low doses of ionizing radiation, and these doses do not appear to be associated with any increase in cancer incidence; the increased incidence of melanoma is more likely related to other risk factors such as exposure to ultraviolet radiation from sunlight.

Dietary risk factors for testicular carcinoma.

Although testicular cancer is a relatively rare lesion, accounting for only 1.1% of all malignant neoplasms in males in Canada, it is the most common cancer among Canadian men 20-45 years of age. Knowledge of the causes of testicular cancer risk in general, and more specifically, its association with diet, remain limited. Data from 601 cases of testicular cancer and 744 population-based controls collected in 8 of the 10 Canadian provinces between 1994-97 were used to explore the relationship between diet and testicular cancer risk. We systematically examined 17 food groups, 15 nutrients and 4 individual foods based on data collected through a 69-item food-frequency questionnaire. Our results suggest that high dairy product intake, in particular high intake of cheese (odds ratio [OR] = 1.87; 95% confidence interval [CI] 1.22-2.86; p-trend < 0.001), is associated with an elevated risk of testicular cancer in Canadian males.

Gradients in risk for youth injury associated with multiple-risk behaviours: a study of 11,329 Canadian adolescents.

This study used the Canadian version of the World Health Organization-Health Behaviour in School-Aged Children (WHO-HBSC) Survey to examine the role of multiple risk behaviours and other social factors in the etiology of medically attended youth injury. 11,329 Canadians aged 11-15 years completed the 1997-1998 WHO-HBSC, of which 4152 (36.7%) reported at least one medically attended injury. Multiple logistic regression analyses failed to identify an expected association between lower socio-economic status and risk for injury. Strong gradients in risk for injury were observed according to the numbers of multiple risk behaviours reported. Youth reporting the largest number (7) of risk behaviours experienced injury rates that were 4.11 times (95% CI: 3.04-5.55) higher than those reporting no high risk behaviours (adjusted odds ratios for 0-7 reported behaviours: 1.00, 1.13, 1.49, 1.79, 2.28, 2.54, 2.62, 4.11; p(trend) < 0.001). Similar gradients in risk were observed within subgroups of young people defined by grade, sex, and socio-economic level, and within restricted analyses of various injury types (recreational, sports, home, school injuries). The gradients were especially pronounced for severe injury types and among those reporting multiple injuries. The analyses suggest that multiple risk behaviours may play an important role in the social etiology of youth injury, but these same analyses provide little evidence for a socio-economic risk gradient. The findings in turn have implications for preventive interventions.