51 resultados para Level 3 evidence


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We investigate the role of foreign currency derivatives (FCD) in alleviating foreign exchange rate exposure of Australian firms. While there is some evidence that the use of FCD reduces the level of ex-post short-term exposure, such an effect is absent with regard to the degree of foreign operations. Our results support the view that FCDs are used to hedge existing exchange rate exposures and that Australian firms, generally, are extensively exposed to currency fluctuations in the long run. While monthly exposure appears to be a function of a firm's size and financial hedging, exchange rate exposure of shorter horizons (1 and 3 months) appears to be negatively related to a firm's price earnings ratio (proxying growth opportunities)—thereby supporting the ‘underinvestment’ hypothesis. Further, the exposure of longer horizons (12 and 24 months) is positively related to a firm's liquidity, supporting the view that liquidity is a substitute for hedging.

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Background: Men who were part of an Australian petroleum industry cohort had previously been found to have an excess of lympho-hematopoietic cancer. Occupational benzene exposure is a possible cause of this excess.

Methods: We conducted a case-control study of lympho-hematopoietic cancer nested within the existing cohort study to examine the role of benzene exposure. Cases identified between 1981 and 1999 (N = 79) were age-matched to 5 control subjects from the cohort. We estimated each subject's benzene exposure using occupational histories, local site-specific information, and an algorithm using Australian petroleum industry monitoring data.

Results: Matched analyses showed that the risk of leukemia was increased at cumulative exposures above 2 ppm-years and with intensity of exposure of highest exposed job over 0.8 ppm. Risk increased with higher exposures; for the 13 case-sets with greater than 8 ppm-years cumulative exposure, the odds ratio was 11.3 (95% confidence interval = 2.85-45.1). The risk of leukemia was not associated with start date or duration of employment. The association with type of workplace was explained by cumulative exposure. There is limited evidence that short-term high exposures carry more risk than the same amount of exposure spread over a longer period. The risks for acute nonlymphocytic leukemia and chronic lymphocytic leukemia were raised for the highest exposed workers. No association was found between non-Hodgkin lymphoma or multiple myeloma and benzene exposure, nor between tobacco or alcohol consumption and any of the cancers.

Conclusions: We found an excess risk of leukemia associated with cumulative benzene exposures and benzene exposure intensities that were considerably lower than reported in previous studies. No evidence was found of a threshold cumulative exposure below which there was no risk.


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Aims & rationale/Objectives : Hypercholesterolaemia accounts for 11.6% of total deaths and 6.2% of the disability burden for the Australian population.1 This paper reports population lipid profiles for three rural Australian populations, and assesses evidence-treatment gaps against the most recent (2005-2007) Australian guidelines.

Methods :
Three population surveys were undertaken in the Greater Green Triangle. 3,320 adults aged 25-74 yrs were randomly selected using age/gender stratified electoral roll samples and of these 1563 subjects participated in the survey. Anthropometric, clinical and self-administered questionnaire data relating to chronic disease risk were collected in accordance with the WHO MONICA protocol.2 A detailed investigation of dyslipidaemia was included.

Principal findings : All required data was available for 1255 participants. Age-standardised mean total cholesterol (TC), triglycerides, LDL cholesterol and HDL cholesterol concentrations were 5.36 mmol/l, 1.42 mmol/l, 3.23 mmol/l and 1.48 mmol/l, respectively. Amongst those taking lipid-lowering medication, just 11% categorised as secondary prevention/diabetes, and 39% as primary prevention, achieved all lipid targets. In the 20% of untreated participants at high risk of a primary cardiovascular event, 26% were aware of their hypercholesterolaemia and just 2% achieved all lipid targets (2.8% achieved TC?5.5 mmol, 8.5% achieved LDL<3.5 mmol/l). 11.2% of the overall population used lipid-lowering medication (95% was statin monotherapy).

Implications : Most adults do not achieve their target lipid profile. This paper identifies the subpopulations and lipid components which need to be targeted for future interventions. It also identifies substantial evidence-treatment gaps which should be addressed to help improve lipid profiles at a population level.

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Background : Dietary ω-3 fatty acid deficiency can lead to hypertension in later life; however, hypertension is affected by numerous other dietary factors. We examined the effect of altering the dietary protein level on blood pressure in animals deficient or sufficient in ω-3 fatty acids.

Methods : Female rats were placed on one of four experimental diets 1 week prior to mating. Diets were either deficient (10% safflower oil; DEF) or sufficient (7% safflower oil, 3% flaxseed oil; SUF) in ω-3 fatty acids and contained 20 or 30% casein (DEF20, SUF20, DEF30, SUF30). Offspring were maintained on the maternal diet for the duration of the experiment. At 12, 18, 24, and 30 weeks, blood pressure was assessed by tail cuff plethysmography.

Results : At both 12 and 18 weeks of age, no differences in blood pressure were observed based on diet, however, by 24 weeks hypertension was evident in DEF30 animals; there were no blood pressure differences between the other groups. This hypertension in DEF30 group was increased at 30 weeks, with systolic, diastolic, and mean arterial pressure all elevated.

Conclusions : These results indicate that the hypertension previously attributed to ω-3 fatty acid deficiency is dependent on additional dietary factors, including protein content. Furthermore, this study is the first to plot the establishment of ω-3 fatty acid deficiency hypertension over time.

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Background: There are few validated measures of organizational context and none that we located are parsimonious and address modifiable characteristics of context. The Alberta Context Tool (ACT) was developed to meet this need. The instrument assesses 8 dimensions of context, which comprise 10 concepts. The purpose of this paper is to report evidence to further the validity argument for ACT. The specific objectives of this paper are to: (1) examine the extent to which the 10 ACT concepts discriminate between patient care units and (2) identify variables that significantly contribute to between-unit variation for each of the 10 concepts.

Methods: 859 professional nurses (844 valid responses) working in medical, surgical and critical care units of 8 Canadian pediatric hospitals completed the ACT. A random intercept, fixed effects hierarchical linear modeling (HLM) strategy was used to quantify and explain variance in the 10 ACT concepts to establish the ACT’s ability to discriminate between units. We ran 40 models (a series of 4 models for each of the 10 concepts) in which we systematically assessed the unique contribution (i.e., error variance reduction) of different variables to between-unit variation. First, we constructed a null model in which we quantified the variance overall, in each of the concepts. Then we controlled for the contribution of individual level variables (Model 1). In Model 2, we assessed the contribution of practice specialty (medical, surgical, critical care) to variation since it was central to construction of the sampling frame for the study. Finally, we assessed the contribution of additional unit level variables (Model 3).

Results: The null model (unadjusted baseline HLM model) established that there was significant variation between units in each of the 10 ACT concepts (i.e., discrimination between units). When we controlled for individual characteristics, significant variation in the 10 concepts remained. Assessment of the contribution of specialty to between-unit variation enabled us to explain more variance (1.19% to 16.73%) in 6 of the 10 ACT concepts. Finally, when we assessed the unique contribution of the unit level variables available to us, we were able to explain additional variance (15.91% to 73.25%) in 7 of the 10 ACT concepts.

Conclusion: The findings reported here represent the third published argument for validity of the ACT and adds to the evidence supporting its use to discriminate patient care units by all 10 contextual factors. We found evidence of relationships between a variety of individual and unit-level variables that explained much of this between-unit variation for each of the 10 ACT concepts. Future research will include examination of the relationships between the ACT’s contextual factors and research utilization by nurses and ultimately the relationships between context, research utilization, and outcomes for patients.

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Aims To assess the association between access to off-premises alcohol outlets and harmful alcohol consumption.
Design, setting and participants Multi-level study of 2334 adults aged 18–75 years from 49 census collector districts (the smallest spatial unit in Australia at the time of survey) in metropolitan Melbourne.
Measurements Alcohol outlet density was defined as the number of outlets within a 1-km road network of respondents’ homes and proximity was the shortest road network distance to the closest outlet from their home. Using multi-level logistic regression we estimated the association between outlet density and proximity and four measures of harmful alcohol consumption: drinking at levels associated with short-term harm at least weekly and monthly; drinking at levels associated with long-term harm and frequency of consumption.
Findings Density of alcohol outlets was associated with increased risk of drinking alcohol at levels associated with harm. The strongest association was for short-term harm at least weekly [odds ratio (OR) 1.10, 95% confidence interval (CI) 1.04–1.16]. When density was fitted as a categorical variable, the highest risk of drinking at levels associated with short-term harm was when there were eight or more outlets (short-term harm weekly: OR 2.36, 95% CI 1.22–4.54 and short-term harm monthly: OR 1.80, 95% CI 1.07–3.04). We found no evidence to support an association between proximity and harmful alcohol consumption.
Conclusions The number of off-premises alcohol outlets in a locality is associated with the level of harmful alcohol consumption in that area. Reducing the number of off-premises alcohol outlets could reduce levels of harmful alcohol consumption.

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Background
Previous studies have provided mixed evidence with regards to associations between food store access and dietary outcomes. This study examines the most commonly applied measures of locational access to assess whether associations between supermarket access and fruit and vegetable consumption are affected by the choice of access measure and scale.

Method
Supermarket location data from Glasgow, UK (n = 119), and fruit and vegetable intake data from the 'Health and Well-Being' Survey (n = 1041) were used to compare various measures of locational access. These exposure variables included proximity estimates (with different points-of-origin used to vary levels of aggregation) and density measures using three approaches (Euclidean and road network buffers and Kernel density estimation) at distances ranging from 0.4 km to 5 km. Further analysis was conducted to assess the impact of using smaller buffer sizes for individuals who did not own a car. Associations between these multiple access measures and fruit and vegetable consumption were estimated using linear regression models.

Results
Levels of spatial aggregation did not impact on the proximity estimates. Counts of supermarkets within Euclidean buffers were associated with fruit and vegetable consumption at 1 km, 2 km and 3 km, and for our road network buffers at 2 km, 3 km, and 4 km. Kernel density estimates provided the strongest associations and were significant at a distance of 2 km, 3 km, 4 km and 5 km. Presence of a supermarket within 0.4 km of road network distance from where people lived was positively associated with fruit consumption amongst those without a car (coef. 0.657; s.e. 0.247; p0.008).

Conclusions
The associations between locational access to supermarkets and individual-level dietary behaviour are sensitive to the method by which the food environment variable is captured. Care needs to be taken to ensure robust and conceptually appropriate measures of access are used and these should be grounded in a clear a priori reasoning.

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This study provides evidence on the principal determinants of pregnancy and abortion in India using a large country-wide district-level data set (DLHS 2007). The paper provides an economic framework for the analysis of pregnancy and abortion. The study distinguishes between induced and spontaneous abortion and compares the effects of their determinants.

The results show that there are wide differences between induced and spontaneous abortions in terms of the sign and magnitude of the estimated effects of several of their determinants, most notably wealth, the woman’s age and her desire for children. The study makes a methodological contribution by proposing a trivariate probit estimation framework that recognizes the joint dependence of pregnancy and induced and spontaneous abortion, and provides evidence in support of this joint dependence.

The study reports an inverted U-shaped effect of a woman’s age on her pregnancy and both forms of abortion. The turning point in each case is quite robust to the estimation framework. A significant effect of contextual variables, at the village level, constructed from the individual responses, on a woman’s pregnancy is found. The effects are weaker in the case of induced abortion, and insignificant in the case of spontaneous abortion. The results are shown to be fairly robust. This paper extends the literature on the relation between son preference and fertility by examining the link between mother’s son preference and desire for more children with abortion rates.

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Research significance: Job insecurity, the subjective individual anticipation of involuntary job loss, negatively affects employees’ health and their engagement. Although the relationship between job insecurity and health has been extensively studied, job insecurity as an ‘exposure’ has received far less attention, with little known about the upstream determinants of job insecurity in particular. This research sought to identify the relationship between self-rated job insecurity and area-level unemployment using a longitudinal, nationally representative study of Australian households. Methods: Mixed-effect multi-level regression models were used to assess the relationship between area-based unemployment rates and self-reported job insecurity using data from a longitudinal, nationally representative survey running since 2001. Interaction terms were included to test the hypotheses that the relationship between area-level unemployment and job insecurity differed between occupational skill-level groups and by employment arrangement. Marginal effects were computed to visually depict differences in job insecurity across areas with different levels of unemployment. Results: Results indicated that areas with the lowest unemployment rates had significantly lower job insecurity (predicted value 2.74; 95% confidence interval (CI) 2.71–2.78, P < 0.001) than areas with higher unemployment (predicted value 2.81; 95% CI 2.79–2.84, P < 0.001). There was a stronger relationship between area-level unemployment and job insecurity among precariously and fixed-term employed workers than permanent workers. Conclusion: These findings demonstrate the independent influences of prevailing economic conditions, individual- and job-level factors on job insecurity. Persons working on a casual basis or on a fixed-term contract in areas with higher levels of unemployment are more susceptible to feelings of job insecurity than those working permanently.

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It is well established that the broad-band muscarinic antagonist, atropine is effective at inhibiting the progression of myopia and does so by preventing the elongation of the vitreous chamber of the eye. However, uncertainty remains as to whether this effect occurs through a receptoral mechanism and, if so, which muscarinic receptor subtype mediates this effect. Previous work, in avian and mammalian models of myopia, implicates the M1 and M4 receptors as potential targets. The current study used physiologically relevant concentrations of highly selective muscarinic antagonists (MT-3 and MT-7) to further characterise the role of the M4 receptor in the control of myopia in the chick model of refractive development.

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Regular exercise and adequate nutrition, particularly dietary calcium, vitamin D, and protein, are prescribed as strategies to optimize peak bone mass and maintain bone and muscle health throughout life. Although the mechanism of action of exercise and nutrition on bone and muscle health are different-exercise has a site-specific modifying effect, whereas nutrition has a permissive generalized effect-there is evidence that combining calcium (or calcium rich dairy foods) or dietary protein with exercise can have a synergetic effect on bone mass and muscle health, respectively. However, many questions still remain as to whether there is a threshold level for these nutrients to optimize the exercise-induced gains. Further studies are also needed to investigate whether other dietary factors, such as vitamin D, soy isoflavones or omega-3 fatty acids, or a multinutrient supplement, can enhance the effects of exercise on bone and muscle health.

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Aims and objectives: To argue that if all nurses were to adopt the primary survey approach (assessment of airway, breathing, circulation and disability) as the first element of patient assessment, they would be more focused on active detection of clinical deterioration rather than passive collection of patient data. Background: Nurses are the professional group that carry the highest level of responsibility for patient assessment, accurate data collection and interpretation. The timely recognition of, and response to deteriorating patients, is dependent on the measurement and interpretation of pertinent physiological data by nurses. Design: Discursive paper. Methods: Traditionally taught and commonly used approaches to patient assessment such as 'vital signs' and 'body systems' are not evidence-based nor framed in patient safety. The primary survey approach as the first element in patient assessment has three major advantages: (1) data are collected according to clinical importance; (2) data are collected using the same framework as most organisation's rapid response system activation criteria; and (3) the primary survey acts as a patient safety checklist, thereby decreasing the risk of failure to recognise, and therefore respond to, deteriorating patients. Conclusion: The vital signs and body systems approaches to patient assessment have significant limitations in identifying clinical deterioration. The primary survey approach provides nurses with a consistent, evidence-based and sequenced approach to patient assessment in every clinical setting. Relevance to clinical practice: All nurses should use a primary survey approach as the first element of patient assessment in every patient encounter as a patient safety strategy. © 2014 John Wiley & Sons Ltd.