Describing the population health burden of depression: health-adjusted life expectancy by depression status in Canada. / Description du fardeau de la dépression sur la santé de la population au Canada : utilisation de l'espérance de vie ajustée en fonction de la santé.

INTRODUCTION: Few studies have evaluated the impact of depression in terms of losses to both premature mortality and health-related quality of life (HRQOL) on the overall population. Health-adjusted life expectancy (HALE) is a summary measure of population health that combines both morbidity and mortality into a single summary statistic that describes the current health status of a population. METHODS: We estimated HALE for the Canadian adult population according to depression status. National Population Health Survey (NPHS) participants 20 years and older (n = 12 373) were followed for mortality outcomes from 1994 to 2009, based on depression status. Depression was defined as having likely experienced a major depressive episode in the previous year as measured by the Composite International Diagnostic Interview Short Form. Life expectancy was estimated by building period abridged life tables by sex and depression status using the relative risks of mortality from the NPHS and mortality data from the Canadian Chronic Disease Surveillance System (2007-2009). The Canadian Community Health Survey (2009/10) provided estimates of depression prevalence and Health Utilities Index as a measure of HRQOL. Using the combined mortality, depression prevalence and HRQOL estimates, HALE was estimated for the adult population according to depression status and by sex. RESULTS: For the population of women with a recent major depressive episode, HALE at 20 years of age was 42.0 years (95% CI: 40.2-43.8) compared to 57.0 years (95% CI: 56.8-57.2) for women without a recent major depressive episode. For the population of Canadian men, HALE at 20 was 39.0 years (95% CI: 36.5-41.5) for those with a recent major depressive episode compared to 53.8 years (95% CI: 53.6-54.0) for those without. For the 15.0-year difference in HALE between women with and without depression, 12.3 years can be attributed to the HRQOL gap and the remaining 2.7 years to the mortality gap. The 14.8 fewer years of HALE observed for men with depression equated to a 13.0-year HRQOL gap and a 1.8-year mortality gap. CONCLUSION: The population of adult men and women with depression in Canada had substantially lower healthy life expectancy than those without depression. Much of this gap is explained by lower levels of HRQOL, but premature mortality also plays a role.

INTRODUCTION: Peu d'études ont évalué, dans l'ensemble d'une population, les conséquences de la dépression en matière de pertes dues à la mortalité prématurée d'une part et à la qualité de vie liée à la santé (QVLS) d'autre part. L'espérance de vie ajustée en fonction de la santé (EVAS) est une mesure synthétique de la santé de la population qui combine la morbidité et la mortalité en une seule statistique succincte décrivant l'état de santé d'une population à un moment donné. MÉTHODOLOGIE: Nous avons estimé la QVLS de la population canadienne adulte en fonction de la présence ou non de dépression. Nous avons effectué un suivi de la mortalité, de 1994 à 2009, des participants à l'Enquête nationale sur la santé de la population (ENSP) (n = 12 373) de 20 ans et plus, là aussi en fonction de la présence ou non de dépression. La dépression a été définie comme l'état d'une personne susceptible d'avoir connu au cours de l'année précédente un épisode dépressif majeur au sens du formulaire abrégé de l'Entrevue composite diagnostique internationale. L'espérance de vie a été estimée en créant des tables abrégées de mortalité selon le sexe et l'état dépressif à l'aide des risques relatifs de mortalité de l'ENSP et des données sur la mortalité du Système canadien de surveillance des maladies chroniques (2007 à 2009). L'Enquête sur la santé dans les collectivités canadiennes (2009-2010) a fourni des estimations de la prévalence de la dépression, et l'indice de l'état de santé Health Utilities Index a permis de mesurer la QVLS. L'EVAS de la population adulte a été mesurée en fonction de la présence ou non de dépression et en fonction du sexe à l'aide des estimations combinées de la mortalité, de la prévalence de la dépression et de la QVLS. RÉSULTATS: Chez les femmes ayant connu récemment un épisode de dépression majeure, l'EVAS à 20 ans était de 42,0 ans (IC à 95 % : 40,2 à 43,8), contre 57,0 ans (IC à 95 % : 56,8 à 57,2) chez les femmes n'ayant pas vécu récemment d'épisode de dépression majeure. Au sein de la population masculine canadienne, l'EVAS à 20 ans était de 39,0 ans (IC à 95 % : 36,5 à 41,5) chez ceux qui avaient connu récemment un épisode de dépression majeure, contre 53,8 ans (IC à 95 % : 53,6 à 54,0) chez ceux n'ayant pas connu récemment d'épisode de dépression majeure. La différence de 15 ans dans l'EVAS des femmes avec et sans épisode récent de dépression majeure peut se décomposer en 12,3 ans attribuables à l'écart de la QVLS et 2,7 ans à l'écart observé en matière de mortalité. Les 14,8 années de moins d'EVAS chez les hommes ayant souffert de dépression correspondent à un écart de la QVLS de 13 ans et à un écart de mortalité de 1,8 an. CONCLUSION: La population canadienne adulte atteinte de dépression au Canada avait une espérance de vie en santé considérablement plus faible que celle ne souffrant pas de dépression, chez les hommes comme chez les femmes. Si la majeure partie de cet écart s'explique par des niveaux moins élevés de la QVLS, la mortalité prématurée joue également un rôle.

Epidemiological characteristics of the carriers with coexistence of HBsAg and anti-HBs based on a community cohort study.

The coexistence of HBsAg and anti-HBs is an atypical serological pattern in HBV infection. There is no epidemiological characteristics of this serological pattern in the community and there is controversy over the molecular mechanisms underlying this pattern. We investigated the epidemiological characteristics of the carriers with HBsAg and anti-HBs in a longitudinal community cohort study. The prevalence of this atypical serological pattern was 2.93% (122/4169) in HBsAg-positive populations. The prevalence progressively increased with age from 40 to 70 years old. The rate of HBeAg positive and detectable HBV DNA were both significantly higher in carriers with this pattern than in carriers who were HBsAg positive but anti-HBs negative (26/122 verse 598/4047, P = 0.046; 86/122 verse 275/529,P < 0.001). After 1 year of follow-up, 85.19% of the carriers still had coexistence HBsAg and anti-HBs, 14.81% of the carriers lost their anti-HBs. Viral sequencing showed that carriers with coexistence of HBsAg and anti-HBs had higher numbers of residue changes within the S gene than carriers who were HBsAg positive but anti-HBs negative (2.42 verse 1.33 changes per 100 residues, P < 0.05). Hence, the coexistence of HBsAg and anti-HBs is a unique serological pattern which may be associated with an increased risk of adverse clinical outcome and may be related to HBsAg immune variants which have genotypic heterogeneity.

Status Report--Retracing the history of the early development of national chronic disease surveillance in Canada and the major role of the Laboratory Centre for Disease Control (LCDC) from 1972 to 2000.

TITRE: Rapport d'étape - Historique des débuts de la surveillance nationale des maladies chroniques au Canada et rôle majeur du Laboratoire de lutte contre la maladie (LLCM) de 1972 à 2000. INTRODUCTION: La surveillance de la santé consiste en l'utilisation systématique et continue de données sur la santé recueillies régulièrement en vue d'orienter les mesures de santé publique en temps opportun. Ce document décrit la création et l'essor des systèmes nationaux de surveillance au Canada et les répercussions de ces systèmes sur la prévention des maladies chroniques et des blessures. En 2008, les auteurs ont commencé à retracer l'historique des débuts de la surveillance nationale des maladies chroniques au Canada, en commençant à 1960, et ils ont poursuivi leur examen jusqu'en 2000. Une publication de 1967 a retracé l'historique de la création du Laboratoire d'hygiène de 1921 à 1967. Notre étude fait suite à cette publication et décrit l'historique de l'établissement de la surveillance nationale des maladies chroniques au Canada, à la fois avant et après la création du Laboratoire de lutte contre la maladie (LCDC).

On the nature of magnetic state in the spinel Co2SnO4.

In the spinel Co2SnO4, coexistence of ferrimagnetic ordering below T(N) ≃ 41 K followed by a spin glass state below T(SG) ≃ 39 K was proposed recently based on the temperature dependence of magnetization M(T) data. Here new measurements of the temperature dependence of the specific heat C(P)(T), ac-susceptibilities χ'(T) and χ″(T) measured at frequencies between 0.51 and 1.2 kHz, and the hysteresis loop parameters (coercivity H(C)(T) and remanence M(R)(T)) in two differently prepared samples of Co2SnO4 are reported. The presence of the Co(2+) and Sn(4+) states is confirmed by x-ray photoelectron spectroscopy (XPS) yielding the structure: Co2SnO4 = [Co(2+)][Co(2+)Sn(4+)]O4. The data of C(P) versus T shows only an inflection near 39 K characteristic of spin-glass ordering. The analysis of the frequency dependence of ac-magnetic susceptibility data near 39 K using the Vogel-Fulcher law and the power-law of the critical slowing-down suggests the presence of spin clusters in the system which is close to a spin-glass state. With a decrease in temperature below 39 K, the temperature dependence of the coercivity H(C) and remanence M(R) for the zero-field cooled samples show both H(C) and M(R) reaching their peak magnitudes near 25 K, then decreasing with decreasing T and becoming negligible below 15 K. The plot of C(P)/T versus T also yields a weak inflection near 15 K. This temperature dependence of H(C) and remanence M(R) is likely associated with the different magnitudes of the magnetic moments of Co(2+) ions on the 'A' and 'B' sites and their different temperature dependence.

Sub-nanosecond time-resolved near-field scanning magneto-optical microscope.

We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of <100 nm. In order to demonstrate the spatiotemporal magnetic imaging capability of this microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 µm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.

Poly(N-isopropyl acrylamide) brush topography: dependence on grafting conditions and temperature.

The topography of poly (N-isopropyl acrylamide) brushes end-grafted from initiator-terminated monolayers was imaged by atomic force microscopy, as a function of the area per chain and of solvent quality. Measurements were done in air and in water, below and above the lower critical solution temperature. At low grafting densities and molecular weights, area-averaged ellipsometry measurements did not detect changes in the volume of water-swollen, end-grafted polymer films above the lower critical solution temperature. However, atomic force microscopy images revealed surface features that suggest the formation of lateral aggregates or "octopus micelles". At high grafting densities and molecular weights, the films collapsed uniformly, as detected by both AFM imaging and ellipsometry. These findings reconcile in part prior results suggesting that some poly(N-isopropyl acrylamide) chains do not collapse in poor solvent, and they also reveal more complex collapse behavior above the lower critical solution temperature than is commonly assumed. This behavior would influence the ability to tune the functional properties of poly(N-isopropyl acrylamide) coatings.

The Association between Obesity and Cancer Risk: A Meta-Analysis of Observational Studies from 1985 to 2011.

Background. Cancer and cardiovascular diseases are the leading causes of mortality and morbidity worldwide. The purpose of this meta-analysis is to synthesize the evidence evaluating the association between obesity and 13 cancers shown previously to be significantly associated with obesity. Methods. Relevant papers from a previously conducted review were included in this paper. In addition, database searches of Medline and Embase identified studies published from the date of the search conducted for the previous review (January, 2007) until May, 2011. The reference lists of relevant studies and systematic reviews were screened to identify additional studies. Relevance assessment, quality assessment, and data extraction for each study were conducted by two reviewers independently. Meta-analysis was performed for men and women separately using DerSimonian and Laird's random effects model. Results. A total of 98 studies conducted in 18 countries from 1985 to 2011 were included. Data extraction was completed on the 57 studies judged to be of strong and moderate methodological quality. Results illustrated that obese men were at higher risk for developing colon (Risk Ratio (RR), 1.57), renal (1.57), gallbladder (1.47), pancreatic (1.36), and malignant melanoma cancers (1.26). Obese women were at higher risk for esophageal adenocarcinoma (2.04), endometrial (1.85), gallbladder (1.82), renal (1.72), pancreatic (1.34), leukemia (1.32), postmenopausal breast (1.25), and colon cancers (1.19). Conclusions. The results of this meta-analysis illustrate a significant, positive, and, for some cancers, strong association between obesity and cancer incidence. Given that approximately 23% of Canadians are obese, a significant proportion of cancer in Canada could be avoided if obesity was eliminated or significantly reduced.

Surveillance of trend and distribution of stroke mortality by subtype, age, gender, and geographic areas in Tianjin, China, 1999-2006.

BACKGROUND: The purpose of this study was to analyze the epidemiological trend and distribution of stroke mortality in the city of Tianjin, China, in order to provide evidence for the prevention and control of stroke. METHODS: The study was based on 102 718 cases of stroke mortality in Tianjin between 1999 and 2006. The cause of death was coded according to the International Classification of Diseases into stroke subtypes. Standardized mortality rates were calculated for stroke and its subtypes, adjusted for age and gender using the year 2000 world standard population. The age, gender, and geographic distribution of stroke and subtype mortality were analyzed. chi2-tests were used to determine the statistical significance of differences in mortality trends. RESULTS: The stroke mortality rate in Tianjin declined from 133.52/100 000/year in 1999 to 102.52/100 000/year in 2006. The stroke mortality rate for males was higher than that for females. Stroke mortality rates increased with increasing age. The subtypes of stroke have changed considerably in Tianjin. Hemorrhagic was major in 1999-2001, while cerebral infarction attained the first rank and accounted for more than 50% of stroke mortality in 2002-2006. The most pronounced finding was that the proportion of ischemic stroke was 66.65% in the urban population and over 20% higher than that in the rural area. Stroke in the suburban area was mainly hemorrhagic stroke, up to 62.67%. CONCLUSIONS: There are significant differences in the distribution of stroke mortality by subtype, age, gender, and geographic areas in Tianjin, China. Various subtypes of stroke are associated with different risk factors and therefore require different public health prevention and control measures. This study provides pertinent information for formulation of measures for the prevention and control of stroke.

Grading of evidence of the effectiveness of health promotion interventions.

AIMS: Grading of evidence of the effectiveness of health promotion interventions remains a priority to the practise of evidence-based health promotion. Several authors propose grading the strength of evidence based on a hierarchy: convincing, probable, possible and insufficient; or strong, moderate, limited and no evidence. Although these grading hierarchies provide simple and straightforward rankings, the terms that describe the categories in the hierarchies, however, do not explain, in an explicit manner, in what way the strength of the evidence in one category is more, or less, superior than that in another. METHODS: To enhance the explanatory power of the hierarchy, we propose that evidence be classified into three grades, each with a short explanatory note on the basis of three criteria: the degree of association between the intervention under study and the outcome factors, the consistency of the findings from different studies, and whether there is a known cause-effect mechanism for the intervention under study and the outcome factors. CONCLUSION: For more in-depth grading, a three-grade expanded hierarchy is also recommended. Examples are given to illustrate our proposed grading schemes.

Finding the real case-fatality rate of H5N1 avian influenza.

BACKGROUND: Accurate estimation of the case-fatality (CF) rate, or the proportion of cases that die, is central to pandemic planning. While estimates of CF rates for past influenza pandemics have ranged from about 0.1% (1957 and 1968 pandemics) to 2.5% (1918 pandemic), the official World Health Organization estimate for the current outbreak of H5N1 avian influenza to date is around 60%. METHODS AND RESULTS: The official estimate of the H5N1 CF rate has been described by some as an over-estimate, with little relevance to the rate that would be encountered under pandemic conditions. The reasons for such opinions are typically: (i) numerous undetected asymptomatic/mild cases, (ii) under-reporting of cases by some countries for economic or other reasons, and (iii) an expected decrease in virulence if and when the virus becomes widely transmitted in humans. Neither current data nor current literature, however, adequately supports these scenarios. While the real H5N1 CF rate could be lower than the current estimate of 60%, it is unlikely that it will be at the 0.1-0.4% level currently embraced by many pandemic plans. We suggest that, based on surveillance and seroprevalence studies conducted in several countries, the real H5N1 CF rate should be closer to 14-33%. CONCLUSIONS: Clearly, if such a CF rate were to be sustained in a pandemic, H5N1 would present a truly dreadful scenario. A concerted and dedicated effort by the international community to avert a pandemic through combating avian influenza in animals and humans in affected countries needs to be a global priority.

Enhancing global capacity in the surveillance, prevention, and control of chronic diseases: seven themes to consider and build upon.

BACKGROUND: Chronic diseases are now a major health problem in developing countries as well as in the developed world. Although chronic diseases cannot be communicated from person to person, their risk factors (for example, smoking, inactivity, dietary habits) are readily transferred around the world. With increasing human progress and technological advance, the pandemic of chronic diseases will become an even bigger threat to global health. METHODS: Based on our experiences and publications as well as review of the literature, we contribute ideas and working examples that might help enhance global capacity in the surveillance of chronic diseases and their prevention and control. Innovative ideas and solutions were actively sought. RESULTS: Ideas and working examples to help enhance global capacity were grouped under seven themes, concisely summarised by the acronym "SCIENCE": Strategy, Collaboration, Information, Education, Novelty, Communication and Evaluation. CONCLUSION: Building a basis for action using the seven themes articulated, especially by incorporating innovative ideas, we presented here, can help enhance global capacity in chronic disease surveillance, prevention and control. Informed initiatives can help achieve the new World Health Organization global goal of reducing chronic disease death rates by 2% annually, generate new ideas for effective interventions and ultimately bring global chronic diseases under greater control.

Influenza-related deaths and hospitalizations in Hong Kong: a subtropical area.

BACKGROUND: While influenza vaccination has been widely used in developed countries to reduce mortality and morbidity in high-risk populations, the lack of regional data on the health burden of influenza and the uncertainty of the applicability of data from temperate areas have been major impediments to establishing an evidence-based policy on the wider use of influenza vaccine in tropical and subtropical regions of the world. OBJECTIVES: The aim of this study was to estimate the annual excess deaths and hospitalizations related to influenza in the Hong Kong Special Administrative Region (HKSAR) for the years 1999 and 2000. STUDY DESIGN AND METHODS: Correlation and regression models were used to estimate the excess deaths and hospitalizations related to influenza in the general population of HKSAR for the years 1999 and 2000, using routinely collected mortality and hospitalization data, and virological laboratory data collected by the HKSAR Influenza Surveillance System. RESULTS: The annual mean excess numbers of deaths related to influenza in Hong Kong were estimated to be 613 for pneumonia and influenza, and 2302 for respiratory and circulatory diseases. The mean excess numbers of hospitalizations attributable to influenza were 4051 for pneumonia and influenza, and 15,873 for respiratory and circulatory diseases. The crude influenza-related mortality and hospitalization rates in Hong Kong, a subtropical area, exceeded those documented in temperate regions. CONCLUSIONS: The finding of significant mortality and morbidity related to influenza in a subtropical area is in accordance with the results of previous studies in tropical and subtropical regions. This simple methodology can be used for the development of influenza immunization policy in many developing countries in tropical and subtropical regions. The enormous potential of influenza vaccination in saving lives and reducing suffering warrants serious consideration of the expanded use of influenza vaccine in tropical and subtropical regions.

Nonequilibrium domain pattern formation in mesoscopic magnetic thin film elements assisted by thermally excited spin fluctuations.

The dynamic behavior in the evolving pattern of thermally assisted, nonequilibrium domains in magnetic thin-film elements undergoing ultrafast 180 degrees magnetization reversal was studied. Magnetization reversal enters a fully dynamic regime when the external field conditions are changed much faster than the sample is able to respond. The dynamic pathway develops a complexity not seen in quasistatic reversal but still retains a high level of order with well-developed dynamic domain patterns formed in response to subnanosecond transitions of the external applied magnetic field.

Radiation-spin interaction, Gilbert damping, and spin torque.

Magnetization relaxation processes, which are represented by the Gilbert damping term and the spin torque term in the Landau-Lifshitz-Gilbert (LLG) equation, are described by the radiation-spin interaction (RSI), where the radiation field is produced by magnetization precessional motion itself. It is shown that the LLG equation including the Gilbert damping term and the spin torque term is derived from the spin Hamiltonian containing the RSI. The derivation of the LLG equation is given in a self-consistent method. It is also shown that, according to RSI, the magnitude of the magnetization vector deviates from the magnetization saturation with the order of O(alpha(2)), where alpha is the Gilbert damping parameter.

The correlation of the complex dielectric constant and blood glucose at low frequency.

A new needle-type sample cell was designed and produced to investigate the correlation between blood glucose and electrical parameters using an impedance analyzer. The characteristics of the measurement cells were optimized to give high sensitivity. High sensitivity complex dielectric constant measurements were obtained by calibration with several known fluids. It was observed that the values of the real (epsilon') and the imaginary (epsilon") dielectric constant increase with decreasing glucose contents in the water/glucose system, and that the value of epsilon' in hamster tail changes according to the variation in blood glucose. It is likely that there is a correlation between blood glucose and the value of epsilon', the electrical parameter.