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Biomedical subjects

Keith B G Dear

Publications and source records attributed to Keith B G Dear.

10 recordsLinked to original sources
PubMed2006

A comparison of methods for calculating population exposure estimates of daily weather for health research.

BACKGROUND: To explain the possible effects of exposure to weather conditions on population health outcomes, weather data need to be calculated at a level in space and time that is appropriate for the health data. There are various ways of estimating exposure values from raw data collected at weather stations but the rationale for using one technique rather than another; the significance of the difference in the values obtained; and the effect these have on a research question are factors often not explicitly considered. In this study we compare different techniques for allocating weather data observations to small geographical areas and different options for weighting averages of these observations when calculating estimates of daily precipitation and temperature for Australian Postal Areas. Options that weight observations based on distance from population centroids and population size are more computationally intensive but give estimates that conceptually are more closely related to the experience of the population. RESULTS: Options based on values derived from sites internal to postal areas, or from nearest neighbour sites--that is, using proximity polygons around weather stations intersected with postal areas--tended to include fewer stations' observations in their estimates, and missing values were common. Options based on observations from stations within 50 kilometres radius of centroids and weighting of data by distance from centroids gave more complete estimates. Using the geographic centroid of the postal area gave estimates that differed slightly from the population weighted centroids and the population weighted average of sub-unit estimates. CONCLUSION: To calculate daily weather exposure values for analysis of health outcome data for small areas, the use of data from weather stations internal to the area only, or from neighbouring weather stations (allocated by the use of proximity polygons), is too limited. The most appropriate method conceptually is the use of weather data from sites within 50 kilometres radius of the area weighted to population centres, but a simpler acceptable option is to weight to the geographic centroid.

Health Status↗
PubMed2005

Within-occasion intraindividual variability and preclinical diagnostic status: is intraindividual variability an indicator of mild cognitive impairment?

Intraindividual variability in cognitive test performance has the potential to be a good marker of preclinical Alzheimer's disease status (S. C. Li & U. Lindenberger, 1999). Using cross-sectional community data from 2,317 individuals aged 60-64 years, the authors of this study found that variability was greater in individuals who met criteria for mild cognitive impairment or aging-associated cognitive decline but not for age-associated memory impairment. Higher variability was associated with lower education and a non-English-speaking background. In contrast to previous findings, variability in this study did not contribute uniquely to meeting criteria for mild cognitive impairment. The reasons for the differences may reside in the authors' method of estimating mean independent variability, the use of an occasion-specific measure, or the relatively younger age of the participants. Follow-up of the cohort in 4 years will yield data on the prospective validity of variability as a risk factor for impairment.

Adult↗
PubMed2005

Non-linear relationships between cognitive function and alcohol consumption in young, middle-aged and older adults: the PATH Through Life Project.

AIMS: To investigate associations, including non-linear relationships, between cognitive function and alcohol consumption, testing for moderating effects of age and gender and for differences across outcome measures. Design Cross-sectional general population samples of three age cohorts. Setting Canberra and Queanbeyan, Australia. PARTICIPANTS: The total sample of 7485 consisted of 2404 men and women aged 20-24 years, 2530 aged 40-44 years, and 2551 aged 60-64 years, selected from the electoral rolls. Measurements Self-report data using hand-held computers provided weekly alcohol consumption from the Alcohol Use Disorders Identification Test (AUDIT) frequency, quantity and binge-drinking items, and socio-demographic factors. Spot-the-Word, digits backwards, the Symbol-Digit Modalities Test (SDMT), immediate recall and reaction-time tests were conducted by trained interviewers. FINDINGS: Findings varied across dependent variables, but there was a general tendency for light drinkers (up to 20/10 g alcohol per day in men/women, respectively) to perform better than abstainers, occasional drinkers or those drinking at hazardous/harmful levels (>40/20 g per day in men/women). Poorer performance of hazardous/harmful drinkers was seen only in men, whereas that of abstainers was evident in both sexes but was stronger in women. After adjustment for education and race, male hazardous/harmful drinkers no longer performed significantly less well than light drinkers, whereas male and female abstainers and occasional drinkers still did so. CONCLUSIONS: Abstainers have poorer cognitive function than light drinkers and further investigation is needed to determine what factors contribute to this.

Adult↗
PubMed2004

Prevalence of mild cognitive impairment in 60- to 64-year-old community-dwelling individuals: The Personality and Total Health through Life 60+ Study.

This epidemiological study aimed at determining the prevalence of mild cognitive impairment (MCI) in 60- to 64-year-old individuals using different diagnostic criteria. Community dwelling individuals (n = 2,551) in the age range of 60-64 years were recruited randomly through the electoral roll. They were screened using the MMSE and a short cognitive battery, and those who screened positive underwent detailed medical and cognitive assessments. Extant MCI-related diagnoses were established by consensus. Predictive regression models on the sub-sample were used to determine population prevalence for the diagnoses. Of the 224 subjects who screened positive for MCI, 112 underwent a detailed assessment and 74% met the criteria for at least one recognised diagnosis of mild cognitive deficit (MCI and related diagnoses). By predictive regression modelling, the prevalence of any MCI diagnosis was 13.7% (95% CI 9.1-30.2) in the population of 60- to 64-year-olds. The estimated prevalence rates for specific diagnoses were: MCI 3.7%, ageing-associated cognitive decline 3.1%, Clinical Dementia Rating score (0.5) 2.8%, age-associated memory impairment 1%, other cognitive disorders 0.9%, and mild neurocognitive disorder 0.6%. Agreement on 'caseness' between various proposed diagnoses was at best fair and generally poor. Memory and other cognitive problems not meeting the threshold for dementia are relatively common in 60- to 64-year-old individuals living in the community. The prevalence rate varies up to six-fold according to the diagnostic criteria applied, with limited overlap between diagnoses. There is an urgent need for standardization of the criteria.

Activities of Daily Living↗
PubMed2004

Mental health first aid training of the public in a rural area: a cluster randomized trial [ISRCTN53887541].

BACKGROUND: A Mental Health First Aid course has been developed which trains members of the public in how to give initial help in mental health crisis situations and to support people developing mental health problems. This course has previously been evaluated in a randomized controlled trial in a workplace setting and found to produce a number of positive effects. However, this was an efficacy trial under relatively ideal conditions. Here we report the results of an effectiveness trial in which the course is given under more typical conditions. METHODS: The course was taught to members of the public in a large rural area in Australia by staff of an area health service. The 16 Local Government Areas that made up the area were grouped into pairs matched for size, geography and socio-economic level. One of each Local Government Area pair was randomised to receive immediate training while one served as a wait-list control. There were 753 participants in the trial: 416 in the 8 trained areas and 337 in the 8 control areas. Outcomes measured before the course started and 4 months after it ended were knowledge of mental disorders, confidence in providing help, actual help provided, and social distance towards people with mental disorders. The data were analysed taking account of the clustered design and using an intention-to-treat approach. RESULTS: Training was found to produce significantly greater recognition of the disorders, increased agreement with health professionals about which interventions are likely to be helpful, decreased social distance, increased confidence in providing help to others, and an increase in help actually provided. There was no change in the number of people with mental health problems that trainees had contact with nor in the percentage advising someone to seek professional help. CONCLUSIONS: Mental Health First Aid training produces positive changes in knowledge, attitudes and behaviour when the course is given to members of the public by instructors from the local health service.

Adolescent↗
PubMed2004

Suicide and mental health in rural, remote and metropolitan areas in Australia.

OBJECTIVES: To compare the prevalence of mental health disorders and the use of professional help by area of residence, age and sex; and to determine whether the differences parallel differences in suicide rates. DESIGN: Retrospective cross-sectional analysis of Australian national mortality data (1997-2000) and the National Survey of Mental Health and Wellbeing (1997), using broad area-of-residence classifications based on the Rural, Remote and Metropolitan Area (RRMA) index. MAIN OUTCOME MEASURES: (a) Suicide rates; (b) prevalence of depression, anxiety and substance-use disorders; and (c) use of health professionals for mental health problems - by age, sex and area of residence. RESULTS: Higher suicide rates were evident for men, particularly young men in rural (40.4 per 100 000; z, 3.2) and remote (51.7 per 100 000; z, 7.2) populations compared with metropolitan (31.8 per 100 000) populations. Although the proportion of young men reporting mental health disorders did not differ significantly between rural (23.5%; z, -0.5) and remote (18.8%; z, -1.6) areas compared with metropolitan (25.6%) areas, young men with a mental health disorder from non-metropolitan areas were significantly less likely than those from metropolitan areas to seek professional help for a mental health disorder (11.4% v 25.2%; z, -2.2). CONCLUSIONS: There is a need to investigate why young men in non-metropolitan areas, the population with the greatest suicide risk, do and do not engage with mental health services.

Adult↗
PubMed2003

Changing GPs' antibiotic prescribing: a randomised controlled trial.

A randomised controlled trial involving 54 general practitioners (GPs) was conducted in Canberra, Australian Capital Territory from September 1997 to November 1999. In the first year of the study, 24 GPs, who constituted the active arm of the intervention group, were involved in the consideration of evidence and the development and implementation of a set of clinical guidelines for the treatment of acute respiratory infections. These guidelines were then endorsed in a meeting together with specialist colleagues. In the second year of the study the group of GPs who had been acting as controls, received a moderate intervention consisting of a brief educational event and distribution of the locally developed guidelines. We obtained data from January 1997 to December 1999 from the Health Insurance Commission on prescribing rates for 40 of the doctors in the study. The rate of prescribing was calculated as the number of antibiotic prescriptions per 100 Medicare services. The average yearly prescribing decreased significantly in the intensive intervention group and increased in the moderate intervention group, (p=0.026). A mixed effects longitudinal time series model was fitted to the data to account for seasonal variation of antibiotic prescribing and trends over time. The intensive intervention group significantly reduced their antibiotic prescribing over time compared to the moderate intervention group, (p<0.001). This study has shown that an intensive intervention in which general practitioners were actively engaged in development and consideration of the evidence base for the guidelines resulted in a significant fall in general antibiotic prescribing.

Adult↗
PubMed2002

Research priorities in mental health, Part 2: an evaluationof the current research effort against stakeholders' priorities.

OBJECTIVE: To examine the current distribution of mental health research in Australia and compare this with the priorities of various stakeholder groups. METHOD: A content analysis was carried out on a year's worth of published articles and a year's worth of competitive research grants. A questionnaire for stakeholders was developed in which respondents were asked to rate priorities for research using the same categories. Questionnaires were sent to mental health researchers,members of panels that evaluate mental health research grant applications,general practitioners, psychiatrists, clinical psychologists, mental health nurses, mental health consumer and carer advocates, and members of the National Mental Health Working Group. RESULTS: Different groups of stakeholders tended to have differing perspectives on research priorities, with some major differences between committees that evaluate research grants and consumer and carer groups. Different stakeholder groups also tended to obtain their information about research from different sources. However, there were also a number of areas of agreement. When different research topics are considered,the following tended to be under-researched: affective disorders,suicide, primary care and community settings, prevention and promotion,evaluation of services, Aboriginal and Torres Strait Islander peoples,and socially and economically disadvantaged people. CONCLUSIONS: It is of concern that committees that evaluate research are guided by different values from consumers and carers in setting priorities. Nevertheless, there is consensus across stakeholder groups that a number of areas should be a high priority.

Analysis of Variance↗
PubMedDate not supplied

Projections of future numbers of dementia cases in Australia with and without prevention.

OBJECTIVE: To produce projections of the number of dementia cases in Australia from 2000 to 2050. These projections examine the effects of an ageing population on number of dementia cases and also the potential impact of preventive strategies that delay age of dementia onset. METHOD: Data from several meta-analyses of dementia prevalence and incidence were combined with age-specific population projections to arrive at estimates of future numbers of cases. A statistical model of dementia incidence was developed and used to estimate the effects of delaying onset by up to 5 years. RESULTS: Without prevention, prevalence of dementia is estimated to increase from 172 000 in 2000 to 588 000 in 2050. Over the same period, the incidence of dementia is estimated to increase from 43 000 to 143 000 new cases a year. Delaying onset by 5 years would decrease prevalence in 2050 by 44%. Even a 6-month delay would reduce prevalence by 6%. CONCLUSIONS: Ageing of the population will lead to a rapid increase in number of dementia cases and an increasing burden for the working-age population. However, even modest prevention efforts could lessen the impact.

Age Factors↗