Cohort trends in age of initiation to heroin use

This paper examines gender differences and trends over time in the age of initiation to heroin use. Data from two large surveys: the Sydney component of the ANAIDUS, conducted in 1989, and the ASHIDU, conducted in 1994, were used to examine this issue. Together, these studies contained information on 1,292 individuals who identified themselves as heroin users. Results indicated that, while there were no significant gender differences in age of initiation to heroin use, there was a significant (p < 0.001) time trend in the mean age at which heroin was first used. Specifically, the mean age of first heroin use among individuals born during the interval 1940-1949 was 20.5 years while among those born during 1970-1979 the mean age of first heroin use was 16.5 years. These findings were confirmed by analyses of the National Household Survey. Further analysis of the ASHIDU data indicated that younger age of initiation to heroin use was associated with polydrug use, overdose and crime after the effects of duration of heroin use had been statistically controlled. These findings suggest that there has been both an increase in the willingness of young people to experiment with heroin and an increased availability of the drug over this time. In combination with evidence that there has been an increase in the amount of heroin being imported into Australia, and an increased demand for treatment for opiate dependence, these data suggest that Australia is experiencing an increase in the use of heroin, particularly among youth.

Perceived social support in a large community sample - Age and sex differences

Background. The positive health and wellbeing effects of social support have been consistently demonstrated in the literature since the late 1970s. However, a better understanding of the effects of age and sex is required. Method. We examined the factor structure and reliability of Kessler's Perceived Social Support (KPSS) measure in a community-based sample that comprised younger and older adult cohorts from the Australian Twin Registry (ATR), totalling 11,389 males and females aged 18-95, of whom 887 were retested 25 months later. Results. Factor analysis consistently identified seven factors: support from spouse, twin, children, parents, relatives, friends and helping support. Internal reliability for the seven dimensions ranged from 0.87 to 0.71 and test-retest reliability ranged from 0.75 to 0.48. Perceived support was only marginally higher in females. Age dependencies were explored. Across the age range, there was a slight decline (more marked in females) in the perceived support from spouse, parent and friend, a slight increase in perceived relative and helping support for males but none for females, a substantial increase in the perceived support from children for males and females and a negligible decline in total KPSS for females against a negligible increase for males. The perceived support from twin remained constant. Females were more likely to have a confidant, although this declined with age whilst increasing with age for males. Conclusions. Total scores for perceived social support conflate heterogeneous patterns on sub-scales that differ markedly by age and sex. Our paper describes these relationships in detail in a very large Australian sample.

Do socioeconomic gradients in women's health widen over time and with age

A population-based study was conducted to investigate changes over time in women's well-being and health service use by socio-cconomic status and whether these varied by age. Data from 12,328 mid-age women (aged 45-50 years in 1996) and 10,430 older women (aged 70-75 years) from the Australian Longitudinal Study on Women's Health were analysed. The main outcome measures were changes in the eight dimensions of the Short Form General Health Survey (SF-36) adjusted for baseline scores, lifestyle and behavioural factors; health care utilisation at Survey 2; and rate of deaths (older cohort only). Cross-sectional analyses showed clear socioeconomic differentials in well-being for both cohorts. Differential changes in health across tertiles of socioeconomic status (SES) were more evident in the mid-age cohort than in the older cohort. For the mid-aged women in the low SES tertile, declines in physical functioning (adjusted mean change of -2.4, standard error (SE) 1.1) and general health perceptions (-1.5, SE 1.1) were larger than the high SES group (physical functioning -0.8 SE 1.1, general health perceptions -0.8 SE 1.2). In the older cohort, changes in SF-36 scores over time were similar for all SES groups but women in the high SES group had lower death rates than women in the low SES group (relative risk: 0.79, 95% confidence interval 0.64-0.98). Findings suggest that SES differentials in physical health seem to widen during women's mid-adult years but narrow in older age. Nevertheless, SES remains an important predictor of health, health service use and mortality in older Australian women. (C) 2003 Elsevier Ltd. All rights reserved.

Modeling the age of tropical moist forest fragments in heavily-cleared lowland landscapes of Colombia

Increasingly, large areas of native tropical forests are being transformed into a mosaic of human dominated land uses with scattered mature remnants and secondary forests. In general, at the end of the land clearing process, the landscape will have two forest components: a stable component of surviving mature forests, and a dynamic component of secondary forests of different ages. As the proportion of mature forests continues to decline, secondary forests play an increasing role in the conservation and restoration of biodiversity. This paper aims to predict and explain spatial and temporal patterns in the age of remnant mature and secondary forests in lowland Colombian landscapes. We analyse the age distributions of forest fragments, using detailed temporal land cover data derived from aerial photographs. Ordinal logistic regression analysis was applied to model the spatial dynamics of mature and secondary forest patches. In particular, the effect of soil fertility, accessibility and auto-correlated neighbourhood terms on forest age and time of isolation of remnant patches was assessed. In heavily transformed landscapes, forests account for approximately 8% of the total landscape area, of which three quarters are comprised of secondary forests. Secondary forest growth adjacent to mature forest patches increases mean patch size and core area, and therefore plays an important ecological role in maintaining landscape structure. The regression models show that forest age is positively associated with the amount of neighbouring forest, and negatively associated with the amount of neighbouring secondary vegetation, so the older the forest is the less secondary vegetation there is adjacent to it. Accessibility and soil fertility also have a negative but variable influence on the age of forest remnants. The probability of future clearing if current conditions hold is higher for regenerated than mature forests. The challenge of biodiversity conservation and restoration in dynamic and spatially heterogeneous landscape mosaics composed of mature and secondary forests is discussed. (c) 2004 Elsevier B.V. All rights reserved.

Is pulse palpation helpful in detecting atrial fibrillation? A systematic review

Background Atrial fibrillation in the elderly is common and potentially life threatening. The classical sign of atrial fibrillation is an irregularly irregular pulse. Objective The objective of this research was to determine the accuracy of pulse palpation to detect atrial fibrillation. Methods We searched Medline, EMBASE, and the reference lists of review articles for studies that compared pulse palpation with the electrocardiogram (ECG) diagnosis of atrial fibrillation. Two reviewers independently assessed the search results to determine the eligibility of studies, extracted data, and assessed the quality of the studies. Results We identified 3 studies (2385 patients) that compared pulse palpation with ECG. The estimated sensitivity of pulse palpation ranged from 91% to 100%, while specificity ranged from 70% to 77%. Pooled sensitivity was 94% (95% confidence interval [CI], 84%-97%) and pooled specificity was 72% (95% CI 69%-75%). The pooled positive likelihood ratio was 3.39, while the pooled negative likelihood ratio was 0.10. Conclusions Pulse palpation has a high sensitivity but relatively low specificity for atrial fibrillation. It is therefore useful for ruling out atrial fibrillation. It may also be a useful screen to apply opportunistically for previously undetected atrial fibrillation. Assuming a prevalence of 3% for undetected atrial fibrillation in patients older than 65 years, and given the test's sensitivity and specificity, opportunistic pulse palpation in this age group would detect an irregular pulse in 30% of screened patients, requiring further testing with ECG. Among screened patients, 0.2% would have atrial fibrillation undetected with pulse palpation.

Modifying insect population age structure to control vector-borne disease

Age is a critical determinant of the ability of most arthropod vectors to transmit a range of human pathogens. This is due to the fact that most pathogens require a period of extrinsic incubation in the arthropod host before pathogen transmission can occur. This developmental period for the pathogen often comprises a significant proportion of the expected lifespan of the vector. As such, only a small proportion of the population that is oldest contributes to pathogen transmission. Given this, strategies that target vector age would be expected to obtain the most significant reductions in the capacity of a vector population to transmit disease. The recent identification of biological agents that shorten vector lifespan, such as Wolbachia, entomopathogenic fungi and densoviruses, offer new tools for the control of vector-borne diseases. Evaluation of the efficacy of these strategies under field conditions will be possible due to recent advances in insect age-grading techniques. Implementation of all of these strategies will require extensive field evaluation and consideration of the selective pressures that reductions in vector longevity may induce on both vector and pathogen.

Changes in cigarette smoking among adults in 35 populations in the mid-1980s

Objective-To examine changes in the prevalence of cigarette smoking in 35 study populations of the World Health Organisation's MONICA Project. Design-Data from two independent, community-based surveys conducted, on average, five years apart. Setting-Geographically defined populations in 21 countries mainly in eastern and western Europe. Subjects-Randomly selected men and women aged 25-64 years. Numbers of participants in each study population ranged from 586 to 2817 in each survey. Main outcome measures-Changes in proportions of current smokers, ex-smokers, and never-smokers by age and sex using data collected by standardised methods. Results-Among men, smoking prevalence decreased in most populations, by three to four percentage points over five years. In Beijing, however, it increased in all age groups-overall by 11 percentage points. Among women there were increases in smoking in about half the populations. The increases were mainly in the age group 35-54 years and often in those populations where smoking prevalence among women has been relatively low. Conclusions-Smoking initiation by middle-aged women in parts of southern and eastern Europe and among men of all ages in Beijing is a matter of concern. The various public health measures that have helped to reduce smoking among men in developed countries should be vigorously extended to these other groups now at growing risk of smoking-related disease.

Reducing the toll of opioid overdose deaths in Australia

Opioid overdose mortality among young adults in Australia has increased consistently over the past several decades. Among Australian adults aged 15-44 years, the number of these deaths has increased from six in 1964 to 600 in 1997. The rate (per million adults in this age group) increased 55-fold, from 1.3 in 1964 to 71.5 in 1997, The proportion of all deaths in adults in this age group caused by opioid overdose increased from 0.1% in 1964 to 7.3% in 1997, The magnitude of the increase makes it unlikely to be an artefact of changes in diagnosis, especially as similar increases have also been observed in other countries. These trends are also consistent,vith historical information which indicates that illicit heroin use first came to police attention in Sydney and Melbourne in the late 1960s, There is an urgent need to implement and evaluate a variety of measures to reduce the unacceptable toll of opioid overdose deaths among young Australians. These include: peer education about the risks of polydrug use and overdose after resuming opioid use after periods of abstinence, and attracting more dependent users into opioid maintenance treatment. Measures are also needed to improve responses to overdose by encouraging witnesses to call ambulances, training drug users in CPR, and trialling distribution of the opiate antagonist naloxone to users at high risk of overdose.

Predictors of death and vascular events in the elderly - The Perth Community Stroke Study

Background and Purpose-The goal of the present study was to identify risk factors for vascular disease in the elderly. Methods-We conducted a prospective study of control subjects from a population-based study of stroke in Perth, Western Australia, that was completed in 1989 to 1990 and used record linkage and a survey of survivors to identify deaths and nonfatal vascular events. Data validated through reference to medical records were analyzed with the use of Cox proportional hazards models. Results-Follow-up for the 931 subjects was 88% complete. By June 24, 1994, 198 (24%) of the subjects had died (96 from vascular disease), and there had been 45 nonfatal strokes or myocardial infarctions. The hazard ratio for diabetes exceeded 2.0 for all end points, whereas the consumption of meat >4 times weekly was associated with a reduction in risk of less than or equal to 30%. In most models, female sex and consumption of alcohol were associated with reduced risks, whereas previous myocardial infarction was linked to an increase in risk. Conclusions-There are only limited associations between lifestyle and major vascular illness in old age. Effective health promotion activities in early and middle life may be the key to a longer and healthier old age.

Initial results of ultrasound screening for aneurysm of the abdominal aorta in Western Australia: relevance for endoluminal treatment of aneurysm disease

Background. Increased life expectancy in men during the last thirty years is largely due to the decrease in mortality from cardiovascular disease in the age group 29-69 yr. This change has resulted in a change in the disease profile of the population with conditions such as aneurysm of the abdominal aorta (AAA) becoming more prevalent. The advent of endoluminal treatment for AAA has encouraged prophylactic intervention and fuelled the argument to screen for the disease. The feasibility of inserting an endoluminal graft is dependent on the morphology and growth characteristics of the aneurysm. This study used data from a randomized controlled trial of ultrasound screening for AAA in men aged 65-83 yr in Western Australia for the purpose of determining the norms of the living anatomy in the pressurized infrarenal aorta. Aims. To examine (1) the diameters of the infra-renal aorta in aneurysmal and non-aneurysmal cases, (2) the implications for treatment modalities, with particular reference to endoluminal grafting, which is most dependent on normal and aneurysmal morphology, and (3) any evidence to support the notion that northern Europeans are predisposed to aneurysmal disease. Methods. Using ultrasound, a randomized control trial was established in Western Australia to assess the value of a screening program in males aged 65-83 yr, The infra-renal aorta was defined as aneurysmal if the maximum diameter was 30 mm or more. Aortic diameter was modelled both as a continuous tin mm) and as a binary outcome variable, for those men who had an infra-renal diameter of 30 mm or more. ANOVA and linear regression were used for modelling aortic diameter as a continuum, while chi-square analysis and logistic regression were used in comparing men with and without the diagnosis of AAA. Findings. By December 1998, of 19.583 men had been invited to undergo ultrasound screening for AAA, 12.203 accepted the invitation (corrected response fraction 70.8%). The prevalence of AAA increased with age from 4.8% at 65 yr to 10.8% at 80 yr (chi (2) = 77.9, df = 3, P<0.001). The median (IQR) diameter for the non-aneurysmal group was 21.4 mm (3.3 mm) and there was an increase (<chi>(2) = 76.0, df = 1, P<0.001) in the diameter of the infra-renal aorta with age. Since 27 mm is the 95th centile for the non-aneurysmal infra-renal aorta, a diameter of 30 mm or more is justified as defining an aneurysm. The risk of AAA was higher in men of Australian (OR = 1.0) and northern European origin (OR = 1.0, 95%CL: 0.9. 1.2) compared with those of Mediterranean origin (OR = 0.5, 99%CL: 0.4, 0.7). Conclusion. Although screening has not yet been shown to reduce mortality from AAA. these population-based data assist the understanding of aneurysmal disease and the further development and use of endoluminal grafts for this condition. (C) 2001 Published by Elsevier Science Ltd on behalf of The International Society for Cardiovascular Surgery.