1,832 research outputs found
Carboxyhaemoglobin concentration, smoking habit, and mortality in 25 years in the Renfrew/Paisley prospective cohort study
Objective: To investigate how carboxyhaemoglobin concentration is related to smoking habit and to assess whether carboxyhaemoglobin concentration is related to mortality.
Design: Prospective cohort study.
Setting: Residents of the towns of Renfrew and Paisley in Scotland.
Participants: The whole Renfrew/Paisley study, conducted between 1972 and 1976, consisted of 7048 men and 8354 women aged 45–64 years. This study was based on 3372 men and 4192 women who were screened after the measurement of carboxyhaemoglobin concentration was introduced about halfway through the study.
Main outcome measures: Deaths from coronary heart disease (CHD), stroke, chronic obstructive pulmonary disease (COPD), lung cancer, and all causes in 25 years after screening.
Results: Carboxyhaemoglobin concentration was related to self reported smoking and for each smoking category was higher in participants who reported inhaling than in those who reported not inhaling. Carboxyhaemoglobin concentration was positively related to all causes of mortality analysed (relative rates associated with a 1 SD (2.93) increase in carboxyhaemoglobin for all causes, CHD, stroke, COPD, and lung cancer were 1.26 (95% confidence interval (CI) 1.19 to 1.34), 1.19 (95% CI 1.13 to 1.26), 1.19 (95% CI 1.13 to 1.26), 1.64 (95% CI 1.47 to 1.84), and 1.69 (95% CI 1.60 to 1.79), respectively). Adjustment for self reported cigarette smoking attenuated the associations but they remained relatively strong.
Conclusions: Self reported smoking data were validated by the objective measure of carboxyhaemoglobin concentration. Since carboxyhaemoglobin concentration remained associated with mortality after adjustment for smoking, carboxyhaemoglobin seems to capture more of the risk associated with smoking tobacco than does self reported tobacco consumption alone. Analysing mortality by self reported cigarette smoking underestimates the strength of association between smoking and mortality
Flow Visualization Tests of a 0.004-scale Space Shuttle Vehicle 2A Model (no. 13-OTS) in the MSFC 14-inch Trisonic Wind Tunnel (IS6A)
Documented are representative photographs of surface flow patterns, created by oil flow and shadowgraph techniques, obtained during wind tunnel tests of an 0.004-scale version of the 2A SSV orbiter. The purpose of this test series was to obtain flow visualization photographs to aid in interpretation of test IS1 aero-noise data. The test was conducted at nominal Mach numbers from 0.6 to 3.48. The orbiter was run in proximity to the external tank and solid rocket boosters at angles of attack from -5 deg to +9 deg at 0 deg angle of sideslip
The spin-half Heisenberg antiferromagnet on two Archimedian lattices: From the bounce lattice to the maple-leaf lattice and beyond
We investigate the ground state of the two-dimensional Heisenberg
antiferromagnet on two Archimedean lattices, namely, the maple-leaf and bounce
lattices as well as a generalized - model interpolating between both
systems by varying from (bounce limit) to (maple-leaf
limit) and beyond. We use the coupled cluster method to high orders of
approximation and also exact diagonalization of finite-sized lattices to
discuss the ground-state magnetic long-range order based on data for the
ground-state energy, the magnetic order parameter, the spin-spin correlation
functions as well as the pitch angle between neighboring spins. Our results
indicate that the "pure" bounce () and maple-leaf () Heisenberg
antiferromagnets are magnetically ordered, however, with a sublattice
magnetization drastically reduced by frustration and quantum fluctuations. We
found that magnetic long-range order is present in a wide parameter range and that the magnetic order parameter varies only
weakly with . At a direct first-order transition to
a quantum orthogonal-dimer singlet ground state without magnetic long-range
order takes place. The orthogonal-dimer state is the exact ground state in this
large- regime, and so our model has similarities to the Shastry-Sutherland
model. Finally, we use the exact diagonalization to investigate the
magnetization curve. We a find a 1/3 magnetization plateau for and another one at 2/3 of saturation emerging only at large .Comment: 9 pages, 10 figure
Health-Related Quality of Life (HRQoL) changes in South Australia: comparison of burden of disease morbidity and survey-based health utility estimates
Background: Global research shows a clear transition in health outcomes over the past two decades where improved survival was accompanied by lower health related quality of life (HRQoL) as measured by morbidity and disability. These trends suggest the need to better understand changes in population HRQoL. This paper compares two perspectives on population HRQoL change using burden of disease morbidity estimates from administrative data and self-reports from random and representative population surveys. Methods: South Australian administrative data including inpatient hospital activity, cancer and communicable disease registrations were used within a Burden of Disease study framework to quantify morbidity as Prevalent Years of Life lived with Disease and injury related illness (PYLD) for 1999 to 2008. Self-reported HRQoL was measured using the Assessment of Quality of Life (AQoL) in face to face interviews with at least 3000 respondents in each of South Australia ’ s Health Omnibus Surveys (HOS) in 1998, 2004 and 2008. Results: Age specific PYLD rates for those aged 75 or more increased by 5.1%. HRQoL dis-utility in this age group also increased significantly and beyond the minimally important difference threshold. Underlying increased dis-utility were greater difficulties in independent living (particularly requiring help with household tasks) and psychological well-being (as influenced by pain, discomfort and difficulty sleeping). Conclusions: Consistent with increased quantity of life being accompanied by reduced HRQoL, the analysis indicates older people in South Australia experienced increased morbidity in the decade to 2008. The results warrant routine monitoring of health dis-utility at a population level and improvement to the supply and scope of administrative data.David Banham, Graeme Hawthorne, Robert Goldney, and Julie Ratcliff
The open future, bivalence and assertion
It is highly intuitive that the future is open and the past is closed—whereas it is unsettled whether there will be a fourth world war, it is settled that there was a first. Recently, it has become increasingly popular to claim that the intuitive openness of the future implies that contingent statements about the future, such as ‘there will be a sea battle tomorrow,’ are non-bivalent (neither true nor false). In this paper, we argue that the non-bivalence of future contingents is at odds with our pre-theoretic intuitions about the openness of the future. These are revealed by our pragmatic judgments concerning the correctness and incorrectness of assertions of future contingents. We argue that the pragmatic data together with a plausible account of assertion shows that in many cases we take future contingents to be true (or to be false), though we take the future to be open in relevant respects. It follows that appeals to intuition to support the non-bivalence of future contingents is untenable. Intuition favours bivalence
Modal Ω-Logic: Automata, Neo-Logicism, and Set-Theoretic Realism
This essay examines the philosophical significance of -logic in Zermelo-Fraenkel set theory with choice (ZFC). The duality between coalgebra and algebra permits Boolean-valued algebraic models of ZFC to be interpreted as coalgebras. The modal profile of -logical validity can then be countenanced within a coalgebraic logic, and -logical validity can be defined via deterministic automata. I argue that the philosophical significance of the foregoing is two-fold. First, because the epistemic and modal profiles of -logical validity correspond to those of second-order logical consequence, -logical validity is genuinely logical, and thus vindicates a neo-logicist conception of mathematical truth in the set-theoretic multiverse. Second, the foregoing provides a modal-computational account of the interpretation of mathematical vocabulary, adducing in favor of a realist conception of the cumulative hierarchy of sets
Health-related Quality of Life among hospitalized older people awaiting residential aged care
BACKGROUND: Health related quality of life (HRQoL) in very late life is not well understood. The aim of the present study was to assess HRQoL and health outcomes at four months follow-up in a group of older people awaiting transfer to residential aged care. METHODS: Secondary analysis of data from a randomized controlled trial conducted in three public hospitals in Adelaide. A total of 320 patients in hospital beds awaiting a residential aged care bed participated. Outcome measurements included HRQoL (Assessment of Quality of Life; AQoL), functional level (Modified Barthel Index), hospital readmission rates, survival, and place of residence at four months follow-up. RESULTS: In this frail group the median AQoL was poor at baseline (median 0.02; 95%CI -0.01 - 0.04) and at follow-up (0.05; 95%CI 0.03 - 0.06). On leaving hospital, more than one third of participants who were moving for the first time into nursing home care rated themselves in a state worse than death (AQoL < or = 0.0). Poor HRQoL at discharge from hospital (AQoL < or = 0.0) was a significant predictor of mortality (HR 1.7; 95%CI 1.2 - 2.7), but not hospital readmission nor place of residence at four months follow-up. Improved function was a predictor of improved HRQoL among the surviving cohort. CONCLUSION: People making the transition to residential aged care from hospital have very poor HRQoL, but small gains in function seem to be related to improvement. While functional gains are unlikely to change discharge destination in this frail group, they can contribute to improvements in HRQoL. These gains may be of great significance for individuals nearing the end of life and should be taken into account in resource allocation.Lynne C. Giles, Graeme Hawthorne and Maria Crott
Relation between coronary risk and coronary mortality in women of the Renfrew and Paisley survey: comparison with men
Most epidemiological and intervention studies in patients with coronary artery disease have focused on men, the assumption being that such data can be extrapolated to women. However, there is little evidence to support this belief. We have completed a fifteen-year follow-up of 15 399 adults, including 8262 women, who lived in Renfrew and Paisley and were aged 45-64 years when screened between 1972 and 1976. We identified 490 deaths from coronary heart disease (CHD) in women and 878 in men. Women were more likely to have high cholesterol, to be obese, and to come from lower social classes than men, but they smoked less and had similar blood pressures. The relative risk--top to bottom quintile (95% Cl)--of cholesterol for coronary death after adjustment for all other risk markers was slightly greater in women (1[middle dot]77 [1[middle dot]45, 2[middle dot]16]) than in men (1[middle dot]56 [1[middle dot]32, 1[middle dot]85]), but absolute and attributable risk were lower. Thus, women in the top quintile for cholesterol had lower coronary mortality (6[middle dot]1 deaths per thousand patient years) than men in the bottom quintile (6[middle dot]8 deaths per thousand patient years). Moreover, it was estimated that there would have been only 103 (21 %) fewer CH D deaths in women, yet 211 (24%) fewer in men, if mortality had been the same for women and men in the lowest quintiles of cholesterol. Trends showing similar relative risks in these women, but lower absolute and attributable risks than in men, were present for smoking, diastolic blood pressure, and social class. There was no relation between obesity and coronary death after adjustment for other risks. Our results suggest that some other factors protect women against CHD. The potential for women to reduce their risk of CH D by changes in lifestyle may be less than for men.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30146/1/0000523.pd
Can we derive an 'exchange rate' between descriptive and preference-based outcome measures for stroke? Results from the transfer to utility (TTU) technique
<p>Abstract</p> <p>Background</p> <p>Stroke-specific outcome measures and descriptive measures of health-related quality of life (HRQoL) are unsuitable for informing decision-makers of the broader consequences of increasing or decreasing funding for stroke interventions. The quality-adjusted life year (QALY) provides a common metric for comparing interventions over multiple dimensions of HRQoL and mortality differentials. There are, however, many circumstances when – because of timing, lack of foresight or cost considerations – only stroke-specific or descriptive measures of health status are available and some indirect means of obtaining QALY-weights becomes necessary. In such circumstances, the use of regression-based transformations or mappings can circumvent the failure to elicit QALY-weights by allowing predicted weights to proxy for observed weights. This regression-based approach has been dubbed 'Transfer to Utility' (TTU) regression. The purpose of the present study is to demonstrate the feasibility and value of TTU regression in stroke by deriving transformations or mappings from stroke-specific and generic but descriptive measures of health status to a generic preference-based measure of HRQoL in a sample of Australians with a diagnosis of acute stroke. Findings will quantify the additional error associated with the use of condition-specific to generic transformations in stroke.</p> <p>Methods</p> <p>We used TTU regression to derive empirical transformations from three commonly used descriptive measures of health status for stroke (NIHSS, Barthel and SF-36) to a preference-based measure (AQoL) suitable for attaching QALY-weights to stroke disease states; based on 2570 observations drawn from a sample of 859 patients with stroke.</p> <p>Results</p> <p>Transformations from the SF-36 to the AQoL explained up to 71.5% of variation in observed AQoL scores. Differences between mean predicted and mean observed AQoL scores from the 'severity-specific' item- and subscale-based SF-36 algorithms and from the 'moderate to severe' index- and item-based Barthel algorithm were neither clinically nor statistically significant when 'low severity' SF-36 transformations were used to predict AQoL scores for patients in the NIHSS = 0 and NIHSS = 1–5 subgroups and when 'moderate to severe severity' transformations were used to predict AQoL scores for patients in the NIHSS ≥ 6 subgroup. In contrast, the difference between mean predicted and mean observed AQoL scores from the NIHSS algorithms and from the 'low severity' Barthel algorithms reached levels that could mask minimally important differences on the AQoL scale.</p> <p>Conclusion</p> <p>While our NIHSS to AQoL transformations proved unsuitable for most applications, our findings demonstrate that stroke-relevant outcome measures such as the SF-36 and Barthel Index can be adequately transformed to preference-based measures for the purposes of economic evaluation.</p
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