Liquid-liquid equilibria of binary mixtures of a lipidic ionic liquid with hydrocarbons.

Although structurally diverse, many ionic liquids (ILs) are polar in nature due to the strong coulombic forces inherent in ionic compounds. However, the overall polarity of the IL can be tuned by incorporating significant nonpolar content into one or more of the constituent ions. In this work, the binary liquid-liquid equilibria of one such IL, 1-methyl-3-(Z-octadec-9-enyl)imidazolium bistriflimide, with several hydrocarbons (n-hexane, n-octane, n-decane, cyclohexane, methylcyclohexane, 1-octene) is measured over the temperature range 0-70 °C at ambient pressure using a combination of cloud point and gravimetric techniques. The phase behavior of the systems are similar in that they exhibit two phases: one that is 60-90 mole% hydrocarbon and a second phase that is nearly pure hydrocarbon. Each phase exhibits a weak dependence of composition on temperature (steep curve) above ∼10 °C, likely due to swelling and restructuring of the nonpolar nano-domains of the IL being limited by energetically unfavorable restructuring in the polar nano-domains. The solubility of the n-alkanes decreases with increasing size (molar volume), a trend that continues for the cyclic alkanes, for which upper critical solution temperatures are observed below 70 °C. 1-Octene is found to be more soluble than n-octane, attributable to a combination of its lower molar volume and slightly higher polarity. The COSMO-RS model is used to predict the T-x'-x'' diagrams and gives good qualitative agreement of the observed trends. This work presents the highest known solubility of n-alkanes in an IL to date and tuning the structure of the ionic liquid to maximize the size/shape trends observed may provide the basis for enhanced separations of nonpolar species.

A decade of research using the CASP scale: key findings and future directions.

Since the publication of A Measure of Quality of Life in Early Old Age: The Theory, Development and Properties of a Needs Satisfaction Model (CASP-19) just over 10 years ago, the scale has gone on to be used in a wide variety of studies in over 20 countries across the world and the original paper has become the most highly cited paper for Aging and Mental Health. Therefore it was felt that it was a good time to look back and reflect on the developments in the use of the scale as well as to look forward to what new research is being done and could be done with the measure. To this end we are extremely grateful for the editors for allowing us to bring together a collection of papers that represent cutting edge research using the CASP scale. These papers cover a wide variety of issues, from working conditions to religiosity, from a range of countries, covering Western and Eastern Europe as well as Africa. Each makes an important individual contribution to our understanding of the factors that influence quality of life in later life as well as pointing to the limitations of the measure and future work that can be done in this area.

Fuel poverty and the health of older people: the role of local climate.

BACKGROUND: Fuel poverty is a risk factor for ill-health, particularly among older people. We hypothesized that both the risk of fuel poverty and the strength of its detrimental effects on health would be increased in areas of colder and wetter climate. METHODS: Individual data on respiratory health, hypertension, depressive symptoms and self-rated health were derived from the 2008/09 wave of the English Longitudinal Study of Ageing. Climate data for 89 English counties and unitary authorities were obtained from the UK Met Office. Multilevel regression models (n = 7160) were used to test (i) the association between local climate and fuel poverty risk, and (ii) the association between local climate and the effect of fuel poverty on health (adjusted for age, gender, height, smoking status and household income). RESULTS: Individual risk of fuel poverty varied across counties. However, this variation was not explained by differences in climate. Fuel poverty was significantly related to worse health for two of the outcomes (respiratory health and depressive symptoms). However, there was no significant effect of climate on fuel poverty's association with these outcomes. CONCLUSIONS: Although there is regional variation in England in both the risk of fuel poverty and its effects on health, this variation is not explained by differences in rainfall and winter temperatures.

The claim for patient choice and equity.

Recently, commentators close to and within the UK government have claimed that patient choice can increase equity in the context of the National Health Service. This article critically examines the basis for this claim through analysis of recent speeches and publications authored by secretaries of state for health and their policy advisers. It is concluded that this claim has not developed prospectively from an analysis of the causes of healthcare inequity, or even with a consistent normative definition of equity. The limited justification that is "framed in causal explanations" of inequity has suffered from an apparent disregard of the available evidence.

The development of life course epidemiology.

The present paper reviews the development of life course epidemiology since its origins during the 1990s from biological programming, birth cohort research and the study of health inequalities. Methods of studying the life course are examined, including birth cohort studies, linked register datasets and epidemiological archaeology. Three models of life course epidemiology are described: critical periods, accumulation, and pathways. Their conceptual and empirical differentiation can be difficult, but it is argued that accumulation is the underlying social process driving life course trajectories, while the critical period and pathway models are distinguished by their concern with specific types of aetiological process. Among the advantages of the accumulation model are predictive power, aetiological insights, contributions to health inequality debates and social policy implications. It is emphasised that the life course approach is not opposed to, or an alternative to, a concern with cross-sectional and current effects; major social disruption can have a large and immediate impact on health. Other limitations of the life course approach include a spectrum of impact (life course effects can be strong in relation to physiology, but often are weaker in relation to behaviour and psychological reactions to everyday life) and, more speculatively, the possibility that life course effects are diluted in the older age groups where morbidity and mortality are highest. Three issues for the future of life course epidemiology are identified. Many life course data are collected retrospectively. We need to know which items of information are recalled with what degree of accuracy over how many decades; and what methods of collecting these retrospective data maximise accuracy and duration. Second, the two partners in life course research need to take more seriously each other's disciplines. Social scientists need to be more critical of such measures as self-assessed health, which lacks an aetiology and hence biological plausibility. Natural scientists need to be more critical of such concepts as socio-economic status, which lacks social plausibility because it fails to distinguish between social location and social prestige. Finally, European comparative studies can play an important part in the future development of life course epidemiology if they build on the emerging infrastructure of European comparative research.

Person, place or time? The effect of individual circumstances, area and changes over time on mortality in men, 1995-2001.

This article uses the ONS Longitudinal Study to explore, for a cohort of adult males who were aged 26 or over in 1971, the relative influence on mortality in 1995-2001 of their place of residence and individual socioeconomic circumstances, at three censuses over a 20-year period. Factors examined in this analysis include social class, neighbourhoo deprivation (at ward level), unemployment, residence in the South East region in 1971 or 1981 housing tenure, and change in social class and housing tenure between 1971 and 1991. The variation in mortality attributable to the local authority district of residence in 1991 was also investigated.

How accurately are height, weight and leg length reported by the elderly, and how closely are they related to measurements recorded in childhood?

BACKGROUND: This paper examines (1) the accuracy of self-reported height, leg length and weight in a group of subjects aged 56-78; (2) whether recent measurement of height and weight influences the accuracy of self-reporting and (3) associations between childhood and adult height, leg length and BMI measured in old age. METHODS: All 3182 surviving members of the Boyd Orr cohort were sent postal questionnaires in 1997-1998 and a sub-sample (294) was also clinically examined. RESULTS: Self-reported height was overestimated and body mass index (BMI), based on reported height and weight, underestimated. The mean difference between self-report and measured values were for height: 2.1 cm in males and 1.7 cm in females; for BMI the difference was -1.3 kg/m(2) in males and -1.2 kg/m(2) in females. Shorter individuals and older subjects tended to over-report their height more than others. The overweight under-reported their weight to a greater extent. Recent measurement appeared to decrease over-reporting of height but not weight. Correlations between self-report and measured height and BMI were generally over 0.90, but weaker for leg length (r = 0.70 in males and 0.71 in females). Adult height and leg length were quite closely related to their relative values in childhood (correlation coefficients ranged from 0.66 to 0.84), but associations between adult and childhood BMI were weak (r = 0.19 in males and 0.21 in females). CONCLUSIONS: Self-reported measures of height and weight may be used in studies of the elderly although systematic reporting errors may bias effect estimates. As overweight individuals tend to under-report and the short and underweight tend to over-report, studies investigating associations of disease with height and weight using self-reported measures will underestimate effects. The weak associations between childhood and adult BMI indicate that associations between childhood adiposity and adult cardiovascular disease found in this cohort may reflect the specific effect of childhood overweight, rather than its persistence into adulthood. This suggests that avoidance of adiposity may be as important in childhood as in adulthood.

The "inverse housing law" and respiratory health.

STUDY OBJECTIVE: To investigate whether there is a mismatch within Britain between climate severity and housing quality ("inverse housing law") and whether this mismatch is associated with respiratory health. DESIGN, SETTING AND PARTICIPANTS: Cross sectional observational study. Britain (Scotland, Wales and England). The 3023 male and 3694 female Health and Lifestyle Survey participants with valid data available on all relevant items. MAIN RESULTS: Geographical mapping shows a mismatch between climate severity and housing quality. Individual level analysis shows that lung function is associated with climate and housing, and their interaction, independently of cigarette smoking status. The physical quality of the housing seems to be most important to respiratory health in areas with harsh climate. CONCLUSIONS: Interpretation must be cautious because cross sectional data have been used to investigate processes that are longitudinal and, possibly, selective. Nevertheless, there does seem to be an "inverse housing law", such that some of the worst quality housing is found in areas with severe climate; and, on the balance of probabilities, this inverse housing law affects respiratory health.

Levels of mortality, education, and social conditions in the 107 local education authority areas of England.

STUDY OBJECTIVE: To investigate the relationships between education, social conditions, and mortality. DESIGN: An ecological study relating several measures of mortality to local rates of educational attainment at age 15/16 years and scores on the Department of the Environment's index of local conditions. SETTING: England and its 107 local education authority areas in 1991. MAIN RESULTS: Educational attainment was closely associated with all cause, coronary, and infant mortality and strongly associated with the index of local conditions. This social index was also closely associated with all the measures of mortality. In multiple regression, the social index was the stronger correlate of all cause mortality but for coronary and infant mortality, educational attainment remained highly statistically significant. CONCLUSIONS: Area levels of both educational attainment and deprivation-affluence are strong correlates of local mortality rates in England. In these analyses educational attainment may be indexing the general cultural level of a community. Preliminary investigation with these ecological data suggests that deprivation-affluence has the stronger association but a surer assessment of their relative importance will require individual level information.

Educational attainment, deprivation-affluence and self reported health in Britain: a cross sectional study.

STUDY OBJECTIVE: The level of material deprivation or affluence is strongly and independently correlated with all cause mortality at an area level, but educational attainment, after controlling for deprivation-affluence, remains strongly associated with coronary and infant mortality. This study investigated whether these relations hold at an individual level with self reported morbidity. DESIGN: Analysis of the cross sectional associations of self reported longstanding illness and "not good" or "fairly good" self assessed health with individual educational attainment in seven levels, adjusting for deprivation measures (economic status of head of household, car ownership, housing tenure, overcrowding). SETTING: The 1993 General Household Survey, a random sample of households in Great Britain. PARTICIPANTS: 11,634 subjects aged 22 to 69. MAIN RESULTS: After adjusting for household deprivation, lower educational attainment was significantly associated with longstanding illness in men (odds ratio 1.05 per education category, 95% CI 1.02 to 1.08), but not in women (odds ratio 1.01, 95% CI 0.98 to 1.04). The associations with "not good" or "fairly good" self assessed health were stronger and significant in both men and women (men 1.13, 95% CI 1.10 to 1.17; women 1.10, 95% CI 1.07 to 1.14). The findings were little changed by allowing for people in poor health becoming economically inactive. CONCLUSIONS: The associations of self reported health with deprivation-affluence are stronger than with educational attainment. However, educational attainment is associated with self assessed health in adulthood, independently of deprivation-affluence. Longstanding illness may be associated with educational attainment in men only. Educational attainment may be a marker for childhood socioeconomic circumstances, its association with health may result from occupational characteristics, or education may influence the propensity to follow health education advice.

When does cardiovascular risk start? Past and present socioeconomic circumstances and risk factors in adulthood.

STUDY OBJECTIVES: To compare associations of childhood and adult socioeconomic position with cardiovascular risk factors measured in adulthood. To estimate the effects of adult socioeconomic position after adjustment for childhood circumstances. DESIGN: Cross sectional survey, using the relative index of inequality method to compare socioeconomic differences at different life stages. SETTING: The Whitehall II longitudinal study of men and women employed in London offices of the Civil Service at study baseline in 1985-88. PARTICIPANTS: 4774 men and 2206 women born in the period 1930-53 who were administered questions on early socioeconomic circumstances. MAIN RESULTS: Adult occupational position (employment grade) was inversely associated (high status-low risk) with current smoking and leisure time physical inactivity, with waist/height, and with metabolic risk factors HDL cholesterol, triglycerides, post-load glucose and fibrinogen. Associations of these variables with childhood socioeconomic position (father's Registrar General Social Class) were weaker or absent, with the exception of smoking in women. Childhood social position was associated with adult weight in both sexes and with current smoking, waist/height, HDL cholesterol and fibrinogen in women. Height, a measure of health capital or constitution, was weakly linked with father's social class and more strongly linked with own employment grade. The combination of childhood disadvantage (low father's class) together with a low status clerical occupation in men was particularly associated with higher body mass index as an adult (interaction test p < 0.001). Adjustment for earlier socioeconomic position--using father's class and own education level simultaneously--did not weaken the effects of adult socioeconomic position, except in the case of smoking in women, when the grade effect was reduced by 59 per cent. CONCLUSIONS: Cardiovascular risk factors in adulthood were in general more strongly related to adult than to childhood socioeconomic position. Among women but not men there was a strong but unexplained link between father's class and adult smoking habit. In both sexes degree of obesity was associated with both childhood and adulthood social position. These findings suggest that the socially patterned accumulation of health capital and cardiovascular risk begins in childhood and continues, according to socioeconomic position, during adulthood.

Education and occupational social class: which is the more important indicator of mortality risk?

STUDY OBJECTIVES: In the UK, studies of socioeconomic differentials in mortality have generally relied upon occupational social class as the index of socioeconomic position, while in the US, measures based upon education have been widely used. These two measures have different characteristics; for example, social class can change throughout adult life, while education is unlikely to alter after early adulthood. Therefore different interpretations can be given to the mortality differentials that are seen. The objective of this analysis is to demonstrate the profile of mortality differentials, and the factors underlying these differentials, which are associated with the two socioeconomic measures. DESIGN: Prospective observational study. SETTING: 27 work places in the west of Scotland. PARTICIPANTS: 5749 men aged 35-64 who completed questionnaires and were examined between 1970 and 1973. FINDINGS: At baseline, similar gradients between socioeconomic position and blood pressure, height, lung function, and smoking behaviour were seen, regardless of whether the education or social class measure was used. Manual social class and early termination of full time education were associated with higher blood pressure, shorter height, poorer lung function, and a higher prevalence of smoking. Within education strata, the graded association between smoking and social class remains strong, whereas within social class groups the relation between education and smoking is attenuated. Over 21 years of follow up, 1639 of the men died. Mortality from all causes and from three broad cause of death groups (cardiovascular disease, malignant disease, and other causes) showed similar associations with social class and education. For all cause of death groups, men in manual social classes and men who terminated full time education at an early age had higher death rates. Cardiovascular disease was the cause of death group most strongly associated with education, while the non-cardiovascular non-cancer category was the cause of death group most strongly associated with adulthood social class. The graded association between social class and all cause mortality remains strong and significant within education strata, whereas within social class strata the relation between education and mortality is less clear. CONCLUSIONS: As a single indicator of socioeconomic position occupational social class in adulthood is a better discriminator of socioeconomic differentials in mortality and smoking behaviour than is education. This argues against interpretations that see cultural--rather than material--resources as being the key determinants of socioeconomic differentials in health. The stronger association of education with death from cardiovascular causes than with other causes of death may reflect the function of education as an index of socioeconomic circumstances in early life, which appear to have a particular influence on the risk of cardiovascular disease.

Collecting retrospective data: development of a reliable method and a pilot study of its use.

The present paper argues that a need will remain for data which have been collected retrospectively. Recent developments in oral history and sociology are described to suggest a method of collecting retrospective data which may minimize recall bias. Pilot work is reported on the adaptation of the method for a study of chronic respiratory disease. The results of the pilot study proved promising. The technical properties of the measures appeared adequate. The results of the substantive analysis were consistent with existing knowledge and went beyond existing knowledge to suggest new areas of research. Ways of further validating the method are identified and its wider application discussed.

Pharmaceutical service delivery by community pharmacies in areas of contrasting medical provision.

The clinical content of community pharmacists' work was studied in a well-doctored and a poorly-doctored area. A total of 315 interactions between clients and pharmacy staff were observed. Some level of clinical work was recorded in approximately one-third of these interaction, with this proportion being significantly higher in the poorly-doctored area. Alternative interpretations of these findings are examined.

Collecting retrospective data: accuracy of recall after 50 years judged against historical records.

Recent interest in a lifecourse perspective on health inequalities will rekindle concerns about the accuracy of retrospective data. The present paper demonstrates that recalled information on some types of social circumstances can be obtained with a useful degree of accuracy using an interview technique which helps to minimize recall bias. Lifegrid information about social circumstances during their youth and childhood was collected from 57 subjects in early old age and compared with archive material of the same subjects' social circumstances recorded 50 years previously. A comparison of interview with archive data revealed that a substantial majority of subjects had recalled simple socio-demographic information after a period of 50 years with a useful degree of accuracy. Within lifecourse research, it is concluded, carefully collected retrospective data offer a valuable complement to birth cohort studies, provided that such usage is sensitive to the types of items of information which can, and can not, be recalled accurately.

Social mobility and 21 year mortality in a cohort of Scottish men.

The objective of this prospective cohort study was to determine the contribution of changes in social class within and between generations to mortality risk and to socioeconomic differentials in mortality. In 27 workplaces in the west of Scotland. 5567 men aged 35-64 years when screened, provided information on their father's occupation, their own first occupation and their occupation at screening. Mortality risk, from broad causes of death by intergenerational and intragenerational social mobility groups, was measured after 21 years. For all or some of the 3 routes of mobility (childhood to screening, labour market entry to screening and childhood to labour market entry), increasing values were seen across the 4 groups (stable non manual, upwardly mobile, downwardly mobile and stable manual) for diastolic blood pressure, body mass index, current smoking, early school leaving, angina, bronchitis, severe chest pain, and proportion living in deprived areas. Decreasing values were seen for serum cholesterol, height, FEV1, exercise, never and ex-smokers, wine drinkers and car users. For mobility between childhood and screening and between childhood and labour market entry, mortality risk was highest for the stable manual group and lowest for the stable non manual group for all cause, cardiovascular disease and other causes of death. The upwardly and downwardly mobile groups had intermediate risks. For cancer mortality, the stable manual group had the highest risk with the other groups having lower and similar risks. For mobility between labour market entry and screening, the highest risk was for the downwardly mobile group for all cause and cardiovascular mortality. For cancer mortality, the risk was higher for men in manual social classes at all occasions. Adjustment for risk factors attenuated but could not completely explain the differentials in mortality risk. Overall, major differences in mortality risk were seen between the stable non manual and the stable manual groups, to which social mobility does not contribute. With the exception of the small intragenerationally downwardly mobile group there was little evidence that social mobility itself was associated with mortality outcomes different from those expected on the basis of lifetime socioeconomic experience. This is consistent with the suggestion that the main influence of socioeconomic position on mortality risk is an accumulative one, acting across the lifecourse.

Domestic labour, paid employment and women's health: analysis of life course data.

The relationship between the amount of domestic labour performed by a woman during her lifetime and a variety of self-reported and objective measures of her health in early old age was examined in the female members (n = 155) of a data set containing considerable life course information, including full household, residential and occupational histories. Domestic labour, on its own, proved a weak predictor of health. The relationship strengthened when domestic labour was combined with the hazards of the formal paid employment which the woman had performed. This suggests that it is the combination of domestic labour plus paid employment which influences women's health. The robustness of this conclusion is indicated by its agreement with other studies which reached the same conclusion through an analysis of data with markedly different characteristics.

Life course influences on quality of life in early old age.

A growing literature demonstrates life course influences on health in early old age. The present paper is the first to examine whether similar processes also influence quality of life in early old age. The question is theorised in terms of structured dependency and third age, and the life course pathways by which people arrive at these destinations in later life. The issues are investigated in a unique data set that contains health and life course information on some 300 individuals mostly aged 65-75 years, enhanced in 2000 by postal survey data on quality of life. Several types of life course effect are identified at conventional levels of statistical significance. Long-term influences on quality of life, however, are less marked than those on health. Quality of life in early old age appears to be influenced primarily by current contextual factors such as material circumstances and serious health problems, with the influence of the life course limited mostly to its shaping of an individual's circumstances in later life. The implication for policy is that disadvantage during childhood and adulthood does not preclude good quality of life in early old age.

Social patterning of medical mortality in youth and early adulthood.

It has been suggested that socio-economic gradients in health reduce or disappear during youth, to be re-created during early adulthood through a process of health-related social mobility. The present analysis tests this hypothesis in relation to 'medical mortality', using a data set which is free of numerator-denominator bias. The sample consists of the appropriate age groups in the OPCS Longitudinal Study; 62,647 males and 59,644 females aged 0-14 at the 1971 census. 'Medical mortality' during 1971-1985, calculated as standardised mortality ratios, is analysed by parental social class, housing tenure and car access in 1971. 'Medical mortality' during 1981-1985 is analysed by own social class in 1981. The results suggest that 'medical mortality' is inversely related to social advantage at ages of death 0-9 years, that this gradient flattens or disappears at ages 10-14 and that it re-emerges at ages 15-29. Within the present analysis this apparent re-emergence could not have been due to health-related social mobility. It is concluded that the apparent absence of socio-economic gradients in 'medical mortality' during youth may be an artefact of the high levels of health enjoyed by this age group and its consequent low levels of non-accidental death.

Life course accumulation of disadvantage: childhood health and hazard exposure during adulthood.

The present paper examines the association between physical and social disadvantage during childhood and lifetime exposure to health-damaging environments. Study members were participants of Boyd Orr's clinical, social and dietary survey conducted between 1937 and 1939 and were aged between 5 and 14 years at clinical examination. Study participants were traced and between 1997 and 1998 a random sample of 294 were interviewed. The lifegrid interview method was used to collect full occupational, residential and household histories, from which accumulated lifetime exposures to a range of environmental hazards were estimated. Age-adjusted height during childhood was found to be inversely related to subsequent exposure to all hazards combined (males p = 0.002; females p = 0.001). This relationship was found in males with manual fathers (p = 0.044) and females with non-manual fathers (p = 0.035). Chronic disease during childhood was also associated with greater subsequent hazard exposure in males with manual fathers (p = 0.008). Among females with non-manual fathers, in contrast, chronic disease during childhood was associated with reduced subsequent hazard exposure (p = 0.05). These findings suggest that exposure to health-damaging environments during adulthood may accumulate on top of health disadvantage during childhood and that this process of life course accumulation of disadvantage may vary by gender and childhood social class.