Smoking and health-related quality of life in English general population: Implications for economic evaluations

Copyright @ 2012 Vogl et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Little is known as to how health-related quality of life (HRQoL) when measured by generic instruments such as EQ-5D differ across smokers, ex-smokers and never-smokers in the general population; whether the overall pattern of this difference remain consistent in each domain of HRQoL; and what implications this variation, if any, would have for economic evaluations of tobacco control interventions. Methods: Using the 2006 round of Health Survey for England data (n = 13,241), this paper aims to examine the impact of smoking status on health-related quality of life in English population. Depending upon the nature of the EQ-5D data (i.e. tariff or domains), linear or logistic regression models were fitted to control for biology, clinical conditions, socio-economic background and lifestyle factors that an individual may have regardless of their smoking status. Age- and gender-specific predicted values according to smoking status are offered as the potential 'utility' values to be used in future economic evaluation models. Results: The observed difference of 0.1100 in EQ-5D scores between never-smokers (0.8839) and heavy-smokers (0.7739) reduced to 0.0516 after adjusting for biological, clinical, lifestyle and socioeconomic conditions. Heavy-smokers, when compared with never-smokers, were significantly more likely to report some/severe problems in all five domains - mobility (67%), self-care (70%), usual activity (42%), pain/discomfort (46%) and anxiety/depression (86%) -. 'Utility' values by age and gender for each category of smoking are provided to be used in the future economic evaluations. Conclusion: Smoking is significantly and negatively associated with health-related quality of life in English general population and the magnitude of this association is determined by the number of cigarettes smoked. The varying degree of this association, captured through instruments such as EQ-5D, may need to be fed into the design of future economic evaluations where the intervention being evaluated affects (e.g. tobacco control) or is affected (e.g. treatment for lung cancer) by individual's (or patients') smoking status

Surface critical behavior of bcc binary alloys

The surface critical behavior of bcc binary alloys undergoing a continuous B2-A2 order-disorder transition is investigated in the mean-field (MF) approximation. Our main aim is to provide clear evidence for the fact that surfaces which break the two-sublattice symmetry generically display the critical behavior of the NORMAL transition, whereas symmetry-preserving surfaces exhibit ORDINARY surface critical behavior. To this end we analyze the lattice MF equations for both types of surfaces in terms of nonlinear symplectic maps and derive a Ginzburg-Landau model for the symmetry-breaking (100) surface. The crucial feature of the continuum model is the emergence of an EFFECTIVE ORDERING (``staggered'') SURFACE FIELD, which depends on temperature and the other lattice model parameters, and which explains the appearance of NORMAL critical behavior for symmetry-breaking surfaces.Comment: 16 pages, REVTeX 3.0, 13 EPSF figures, submitted to Phys. Rev.

Surface induced disorder in body-centered cubic alloys

We present Monte Carlo simulations of surface induced disordering in a model of a binary alloy on a bcc lattice which undergoes a first order bulk transition from the ordered DO3 phase to the disordered A2 phase. The data are analyzed in terms of an effective interface Hamiltonian for a system with several order parameters in the framework of the linear renormalization approach due to Brezin, Halperin and Leibler. We show that the model provides a good description of the system in the vicinity of the interface. In particular, we recover the logarithmic divergence of the thickness of the disordered layer as the bulk transition is approached, we calculate the critical behavior of the maxima of the layer susceptibilities, and demonstrate that it is in reasonable agreement with the simulation data. Directly at the (110) surface, the theory predicts that all order parameters vanish continuously at the surface with a nonuniversal, but common critical exponent. However, we find different exponents for the order parameter of the DO3 phase and the order parameter of the B2 phase. Using the effective interface model, we derive the finite size scaling function for the surface order parameter and show that the theory accounts well for the finite size behavior of the DO3 ordering but not for that of B2 ordering. The situation is even more complicated in the neighborhood of the (100) surface, due to the presence of an ordering field which couples to the B2 order.Comment: To appear in Physical Review

Sex Ratio at Birth in India, Its Relation to Birth Order, Sex of Previous Children and Use of Indigenous Medicine

Objective: Sex-ratio at birth in families with previous girls is worse than those with a boy. Our aim was to prospectively study in a large maternal and child unit sex-ratio against previous birth sex and use of traditional medicines for sex selection. Main Outcome Measures: Sex-ratio among mothers in families with a previous girl and in those with a previous boy, prevalence of indigenous medicine use and sex-ratio in those using medicines for sex selection. Results: Overall there were 806 girls to 1000 boys. The sex-ratio was 720:1000 if there was one previous girl and 178:1000 if there were two previous girls. In second children of families with a previous boy 1017 girls were born per 1000 boys. Sexratio in those with one previous girl, who were taking traditional medicines for sex selection, was 928:1000. Conclusion: Evidence from the second children clearly shows the sex-ratio is being manipulated by human interventions. More mothers with previous girls tend to use traditional medicines for sex selection, in their subsequent pregnancies. Those taking such medication do not seem to be helped according to expectations. They seem to rely on this method and so are less likely use more definitive methods like sex selective abortions. This is the first such prospective investigation of sex ratio in second children looked at against the sex of previous children. More studies are needed to confirm the findings

Experience-based VAS values for EQ-5D-3L health states in a national general population health survey in China

Purpose: To investigate the feasibility of deriving experience-based visual analogue scale (VAS) values for EQ-5D-3L health states using national general population health survey data in China. Methods: The EQ-5D-3L was included in the National Health Services Survey (n = 120,709, aged 15–103 years) to measure health-related quality of life. The respondents reported their current health status on a VAS and completed the EQ-5D-3L questionnaire, enabling modelling of the association between the experience-based VAS values and self-reported problems on EQ-5D dimensions and severity levels. Results: VAS values were generally negatively associated with problems reported on the EQ-5D dimensions, and the anxiety/depression dimension had the greatest impact on VAS values. A previously obtained value for dead allowed the values for all 243 EQ-5D-3L health states to be transformed to the 0–1 scale (0 = dead, 1 = full health). Conclusions: This study presents the feasibility of deriving an experience-based VAS values for EQ-5D-3L health states in China. The analysis of these VAS data raises more fundamental issues concerning the universal nature of the classification system and the extent to which Chinese respondents utilise the same concepts of health as defined by this classification system

Experience-based utility and own health state valuation for a health state classification system: why do it and how to do it

In the estimation of population value sets for health state classification systems such as the EQ-5D, there is increasing interest in asking respondents to value their own health state, sometimes referred to as "experienced-based utility values" or more correctly ownrather than hypothetical health states. Own health state values differ to hypothetical health state values, and this may be attributed to many reasons. This paper critically examines: whose values matter; why there is a difference between own and hypothetical values; how to measure own health state values; and why to use own health state values. Finally, the paper also examines other ways that own health state values can be taken into account, such as including the use of informed general population preferences that may better take into account experience-based values

Uncertainty in energy yield estimation based on C-Si module roundrobin results.

Results of the European FP7 Sophia project roundrobin of c-Si module power measurements at STC and low irradiance and temperature coefficients were used to calculate annual energy yield at four sites. The deviation in the estimates solely due to the different measurement results is reported, neglecting the uncertainty in the meteorological data and losses unrelated to the performed measurements. While minimising the deviation in Pmax measurements remains the key challenge, the low irradiance and temperature coefficient contributions are shown to be significant. Propagating the measurement deviation in c-Si module measurements would suggest that expanded uncertainty in energy yield due to module characterization alone can be as high as ±3-4%

Results of the Sophia module intercomparison part-1: stc, low irradiance conditions and temperature coefficients measurements of C-Si technologies

The results of a measurement intercomparison between eleven European laboratories measuring PV energy relevant parameters are reported. The purpose of the round-robin was to assess the uncertainty analyses of the participating laboratories on c-Si modules and to establish a baseline for the following thin-film round-robin. Alongside the STC measurements, low irradiance conditions (200W/m2) and temperature coefficients measurements were performed. The largest measurement deviation from the median at STC was for HIT modules from -3.6% to +2.7% in PMAX, but in agreement with the stated uncertainties of the participants. This was not the case for low irradiance conditions and temperature coefficients measurements with some partners underestimating their uncertainties. Larger deviations from the median from -5% to +3% in PMAX at low irradiance conditions and -6.6% to +18.3% for the PMAX temperature coefficient were observed. The main sources of uncertainties contributing to the spread in measurements were the RC calibration, mismatch factor and capacitive effects at STC and low irradiance conditions as well as the additional light inhomogeneity for the latter. The uncertainty in the junction temperature and the temperature deviation across the module were the major contributors for temperature coefficients measurements