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

An In Vitro Analysis of a One-Way Arterial Check Valve

The utilization of a centrifugal pump during extracorporeal circulation may result in retrograde blood flow through the circuit. The non-occlusive characteristics of a centrifugal pump could create a condition where regurgitant flow is possible when the pressure in the cannulated vessel exceeded the pressure in the extracorporeal circuit. The reversal of flow, from patient to pump, could entrain air from multiple points including cannulation sites, suture holes, or open vessels or chambers. The following study was conducted to evaluate the ability of an arterial check valve (ACV) to prevent retrograde flow. An in vitro circuit was designed to evaluate the flow dynamics of an ACV under a variety of test conditions including the following: flow rates between 0 and 7.5 L/min, and at temperatures of 37°, 25° and 15°C. The design characteristics of the ACV permitted easy priming, aided by gentle turbulence at the junction of the valve attachment to the casing. There was no difference in pressure drop across the ACV at any flow when compared to an identical circuit without the valve. The pressure drop across the ACV never exceeded 5 mmHg, at any temperature, when flow was less than 2 L/min. Retrograde leak volume was determined by creating "back" pressures on the valve, ranging from 25 to 500 mmHg. One ACV malfunctioned at a back pressure of 250 mmHg, and the data for that valve was omitted for comparative purposes. On the remaining valves, leak volume did not exceed 1.2 ml, and was a result of the compliance of the leaflet structures causing a slight volume displacement due to valve motion in a retrograde fashion. The results of this study show that the ACV permitted unimpeded, unidirectional flow at all operating conditions considered clinically relevant, and may be efficacious in alleviating the chance of retrograde circuit flow

Physical Activity, Weight, and Waist Circumference in Midlife Women

During midlife years, women are at risk of increasing body weight and waist circumference. We evaluated changes in weight and waist circumference from enrollment to 2 years later and examined the influence of physical activity level on those changes among 232 women aged between 40-50. Weight increased significantly for the entire sample. Those who increased their physical activity from enrollment to 2 years later had the smallest increase in weight and had a slight decrease in waist circumference. To maintain ideal weight and waist circumference, midlife women should be encouraged to increase physical activity before and during the menopausal transition