Fundamental efficiency bound for coherent energy transfer in nanophotonics

We derive a unified quantum theory of coherent and incoherent energy transfer between two atoms (donor and acceptor) valid in arbitrary Markovian nanophotonic environments. Our theory predicts a fundamental bound $\eta_{max} = \frac{\gamma_a}{\gamma_d + \gamma_a}$ for energy transfer efficiency arising from the spontaneous emission rates $\gamma_{d}$ and $\gamma_a$ of the donor and acceptor. We propose the control of the acceptor spontaneous emission rate as a new design principle for enhancing energy transfer efficiency. We predict an experiment using mirrors to enhance the efficiency bound by exploiting the dipole orientations of the donor and acceptor. Of fundamental interest, we show that while quantum coherence implies the ultimate efficiency bound has been reached, reaching the ultimate efficiency does not require quantum coherence. Our work paves the way towards nanophotonic analogues of efficiency enhancing environments known in quantum biological systems.Comment: 5 pages, 4 figure

Visualising linked health data to explore health events around preventable hospitalisations in NSW Australia

Objective: To explore patterns of health service use in the lead-up to, and following, admission for a ‘preventable’ hospitalisation. Setting: 266 950 participants in the 45 and Up Study, New South Wales (NSW) Australia Methods: Linked data on hospital admissions, general practitioner (GP) visits and other health events were used to create visual representations of health service use. For each participant, health events were plotted against time, with different events juxtaposed using different markers and panels of data. Various visualisations were explored by patient characteristics, and compared with a cohort of non-admitted participants matched on sociodemographic and health characteristics. Health events were displayed over calendar year and in the 90 days surrounding first preventable hospitalisation. Results: The visualisations revealed patterns of clustering of GP consultations in the lead-up to, and following, preventable hospitalisation, with 14% of patients having a consultation on the day of admission and 27% in the prior week. There was a clustering of deaths and other hospitalisations following discharge, particularly for patients with a long length of stay, suggesting patients may have been in a state of health deterioration. Specialist consultations were primarily clustered during the period of hospitalisation. Rates of all health events were higher in patients admitted for a preventable hospitalisation than the matched non-admitted cohort. Conclusions: We did not find evidence of limited use of primary care services in the lead-up to a preventable hospitalisation, rather people with preventable hospitalisations tended to have high levels of engagement with multiple elements of the healthcare system. As such, preventable hospitalisations might be better used as a tool for identifying sicker patients for managed care programmes. Visualising longitudinal health data was found to be a powerful strategy for uncovering patterns of health service use, and such visualisations have potential to be more widely adopted in health services research

Using weighted hospital service area networks to explore variation in preventable hospitalization

Objective: To demonstrate the use of multiple-membership multilevel models, which analytically structure patients in a weighted network of hospitals, for exploring between-hospital variation in preventable hospitalizations. Data Sources: Cohort of 267,014 people aged over 45 in NSW, Australia. Study Design: Patterns of patient flow were used to create weighted hospital service area networks (weighted-HSANs) to 79 large public hospitals of admission. Multiple-membership multilevel models on rates of preventable hospitalization, modeling participants structured within weighted-HSANs, were contrasted with models clustering on 72 hospital service areas (HSAs) that assigned participants to a discrete geographic region. Data Collection/Extraction Methods: Linked survey and hospital admission data. Principal Findings: Between-hospital variation in rates of preventable hospitalization was more than two times greater when modeled using weighted-HSANs rather than HSAs. Use of weighted-HSANs permitted identification of small hospitals with particularly high rates of admission and influenced performance ranking of hospitals, particularly those with a broadly distributed patient base. There was no significant association with hospital bed occupancy. Conclusion: Multiple-membership multilevel models can analytically capture information lost on patient attribution when creating discrete health care catchments. Weighted-HSANs have broad potential application in health services research and can be used across methods for creating patient catchments

Mental health literacy: a cross-cultural approach to knowledge and beliefs about depression, schizophrenia and generalized anxiety disorder

Many families worldwide have at least one member with a behavioral or mental disorder, and yet the majority of the public fails to correctly recognize symptoms of mental illness. Previous research has found that Mental Health Literacy (MHL)—the knowledge and positive beliefs about mental disorders—tends to be higher in European and North American cultures, compared to Asian and African cultures. Nonetheless quantitative research examining the variables that explain this cultural difference remains limited. The purpose of our study was fourfold: (a) to validate measures of MHL cross-culturally, (b) to examine the MHL model quantitatively, (c) to investigate cultural differences in the MHL model, and (d) to examine collectivism as a predictor of MHL. We validated measures of MHL in European American and Indian samples. The results lend strong quantitative support to the MHL model. Recognition of symptoms of mental illness was a central variable: greater recognition predicted greater endorsement of social causes of mental illness and endorsement of professional help-seeking as well as lesser endorsement of lay help-seeking. The MHL model also showed an overwhelming cultural difference; namely, lay help-seeking beliefs played a central role in the Indian sample, and a negligible role in the European American sample. Further, collectivism was positively associated with causal beliefs of mental illness in the European American sample, and with lay help-seeking beliefs in the Indian sample. These findings demonstrate the importance of understanding cultural differences in beliefs about mental illness, particularly in relation to help-seeking beliefs

Assessing preventable hospitalisation indicators (APHID): protocol for a data-linkage study using cohort study and administrative data

Introduction Potentially preventable hospitalisation (PPH) has been adopted widely by international health systems as an indicator of the accessibility and overall effectiveness of primary care. The Assessing Preventable Hospitalisation InDicators (APHID) study will validate PPH as a measure of health system performance in Australia and Scotland. APHID will be the first large-scale study internationally to explore longitudinal relationships between primary care and PPH using detailed person-level information about health risk factors, health status and health service use. Methods and analysis APHID will create a new longitudinal data resource by linking together data from a large-scale cohort study (the 45 and Up Study) and prospective administrative data relating to use of general practitioner (GP) services, dispensing of pharmaceuticals, emergency department presentations, hospital admissions and deaths. We will use these linked person-level data to explore relationships between frequency, volume, nature and costs of primary care services, hospital admissions for PPH diagnoses, and health outcomes, and factors that confound and mediate these relationships. Using multilevel modelling techniques, we will quantify the contributions of person-level, geographic-level and service-level factors to variation in PPH rates, including socioeconomic status, country of birth, geographic remoteness, physical and mental health status, availability of GP and other services, and hospital characteristics. Ethics and dissemination Participants have consented to use of their questionnaire data and to data linkage. Ethical approval has been obtained for the study. Dissemination mechanisms include engagement of policy stakeholders through a reference group and policy forum, and production of summary reports for policy audiences in parallel with the scientific papers from the study.</p

Mental health first aid training for the public: evaluation of effects on knowledge, attitudes and helping behavior

BACKGROUND: Many members of the public have poor mental health literacy. A Mental Health First Aid training course was developed in order to improve this. This paper describes the training course and reports an evaluation study looking at changes in knowledge, stigmatizing attitudes and help provided to others. METHODS: Data are reported on the first 210 participants in public courses. Evaluation questionnaires were given at the beginning of courses, at the end and at 6 months follow-up. Data were analyzed using an intention-to-treat approach. RESULTS: The course improved participants' ability to recognize a mental disorder in a vignette, changed beliefs about treatment to be more like those of health professionals, decreased social distance from people with mental disorders, increased confidence in providing help to someone with a mental disorder, and increased the amount of help provided to others. CONCLUSIONS: Mental Health First Aid training appears to be an effective method of improving mental health literacy which can be widely applied

Predictors of refusal to participate: a longitudinal health survey of the elderly in Australia

BACKGROUND: The loss of participants in longitudinal studies due to non-contact, refusal or death can introduce bias into the results of such studies. The study described here examines reasons for refusal over three waves of a survey of persons aged ≥ 70 years. METHODS: In a longitudinal study involving three waves, participants were compared to those who refused to participate but allowed an informant to be interviewed and to those who refused any participation. RESULTS: At Wave 1 both groups of Wave 2 non-participants had reported lower occupational status and fewer years of education, had achieved lower verbal IQ scores and cognitive performance scores and experienced some distress from the interview. Those with an informant interview only were in poorer physical health than those who participated and those who refused. Depression and anxiety symptoms were not associated with non-participation. Multivariate analyses found that verbal IQ and cognitive impairment predicted refusal. Results were very similar for refusers at both Waves 2 and 3. CONCLUSIONS: Longitudinal studies of the elderly may over estimate cognitive performance because of the greater refusal rate of those with poorer performance. However, there is no evidence of bias with respect to anxiety or depression

Age differences in mental health literacy

BACKGROUND: The community's knowledge and beliefs about mental health problems, their risk factors, treatments and sources of help may vary as a function of age. METHODS: Data were taken from an epidemiological survey conducted during 2003–2004 with a national clustered sample of Australian adults aged 18 years and over. Following the presentation of a vignette describing depression (n = 1001) or schizophrenia (n = 997), respondents were asked a series of questions relating to their knowledge and recognition of the disorder, beliefs about the helpfulness of treating professionals and medical, psychological and lifestyle treatments, and likely causes. RESULTS: Participant age was coded into five categories and cross-tabulated with mental health literacy variables. Comparisons between age groups revealed that although older adults (70+ years) were poorer than younger age groups at correctly recognising depression and schizophrenia, young adults (18–24 years) were more likely to misidentify schizophrenia as depression. Differences were also observed between younger and older age groups in terms of beliefs about the helpfulness of certain treating professionals and medical and lifestyle treatments for depression and schizophrenia, and older respondents were more likely to believe that schizophrenia could be caused by character weakness. CONCLUSION: Differences in mental health literacy across the adult lifespan suggest that more specific, age appropriate messages about mental health are required for younger and older age groups. The tendency for young adults to 'over-identify' depression signals the need for awareness campaigns to focus on differentiation between mental disorders

Home and community care services: a major opportunity for preventive health care

BACKGROUND In Australia, the Home and Community Care (HACC) program provides services in the community to frail elderly living at home and their carers. Surprisingly little is known about the health of people who use these services. In this study we sought to describe health-related factors associated with use of HACC services, and to identify potential opportunities for targeting preventive services to those at high risk. METHODS We obtained questionnaire data from the 45 and Up Study for 103,041 men and women aged 45 years and over, sampled from the general population of New South Wales, Australia in 2006-2007, and linked this with administrative data about HACC service use. We compared the characteristics of HACC clients and non-clients according to a range of variables from the 45 and Up Study questionnaire, and estimated crude and adjusted relative risks for HACC use with generalized linear models. RESULTS 4,978 (4.8%) participants used HACC services in the year prior to completing the questionnaire. Increasing age, female sex, lower pre-tax household income, not having a partner, not being in paid work, Indigenous background and living in a regional or remote location were strongly associated with HACC use. Overseas-born people and those speaking languages other than English at home were significantly less likely to use HACC services. People who were underweight, obese, sedentary, who reported falling in the past year, who were current smokers, or who ate little fruit or vegetables were significantly more likely to use HACC services. HACC service use increased with decreasing levels of physical functioning, higher levels of psychological distress, and poorer self-ratings of health, eyesight and memory. HACC clients were more likely to report chronic health conditions, in particular diabetes, stroke, Parkinson's disease, anxiety and depression, cancer, heart attack or angina, blood clotting problems, asthma and osteoarthritis. CONCLUSIONS HACC clients have high rates of modifiable lifestyle risk factors and health conditions that are amenable to primary and secondary prevention, presenting the potential for implementing preventive health care programs in the HACC service setting.This study was supported by a HACC grant from the NSW Department of Ageing, Disability and Home Care

Cross-cultural generalizability of suicide first aid actions: an analysis of agreement across expert consensus studies from a range of countries and cultures

Background A number of Delphi expert consensus studies have been carried out with different countries and cultural groups to develop guidelines on how a member of the public should provide assistance to a person who is suicidal. The present study aimed to determine whether cross-culturally generalizable suicide first aid actions are possible by comparing agreement across these Delphi studies. Methods Data on endorsement rates for items were compared across six Delphi studies. These studies involved panels of professionals and consumer advocates from English-speaking countries, professionals from Sri Lanka, professionals from Japan, professionals from India, professionals from the Philippines, and professionals and consumer advocates in refugee and immigrant mental health. Correlations were calculated between item endorsement rates across panels. Results There were 18 items that were highly endorsed across all eight of the Delphi panels and an additional 15 items highly endorsed across the panels from the three lower middle-income countries (India, Philippines and Sri Lanka). Correlations across panels in item endorsement rates were all 0.60 or above, but were higher between panels from countries that are socioeconomically similar. Conclusions There is broad agreement across the diverse expert panels about what are appropriate suicide first aid actions for members of the public, indicating that cross-cultural generalizability is possible. However, there is also some cultural specificity, indicating the need for local tailoring