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Concentration Index (concentration + index)

Distribution by Scientific Domains

Physics and Astronomy	40%

Selected Abstracts

Horizontal equity in utilisation of care and fairness of health financing: a comparison of micro-health insurance and user fees in Rwanda

HEALTH ECONOMICS, Issue 1 2006
Pia Schneider
Abstract This paper uses two methods to compare the impact of health care payments under insurance and user fees. Concentration indices for insured and uninsured groups are computed following the indirect standardisation method to evaluate horizontal inequity in utilisation of basic health care services. The minimum standard approach analyses the extent to which out-of-pocket health spending contributed to increased poverty. The analysis uses cross-sectional household survey data collected in Rwanda in 2000 in the context of the introduction of community-based health insurance. Results indicate that health spending had a small impact on the socio-economic situation of uninsured and insured households; however, this is at the expense of horizontal inequity in utilisation of care for user-fee paying individuals who reported significantly lower visit rates than the insured. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Sometimes more equal than others: how health inequalities depend on the choice of welfare indicator

HEALTH ECONOMICS, Issue 3 2006
Magnus Lindelow
Abstract In recent years, a large body of empirical work has focused on measuring and explaining socio-economic inequalities in health outcomes and health service use. In any effort to address these questions, analysts must confront the issue of how to measure socioeconomic status. In developing countries, socioeconomic status has typically been measured by per capita consumption or an asset index. Currently, there is only limited information on how the choice of welfare indicators affect the analysis of health inequalities and the incidence of public spending. The purpose of this paper is to illustrate the potential sensitivity of the analysis of health related inequalities to how socioeconomic status is measured. Using data from Mozambique, the paper focuses on five key health service indicators, and tests whether measured inequality (concentration index) in health service utilization differs depending on the choice of welfare indicator. The paper shows that, at least in some contexts, the choice of welfare indicator can have a large and significant impact on measured inequality in utilization of health services. In consequence, we can reach very different conclusions about the ,same' issue depending on how we define socioeconomic status. The paper also provides some tentative conclusions about why and in what contexts health inequalities can be sensitive to the choice of living standards measure. The results call for more clarity and care in the analysis of health related inequalities, and for explicit recognition of the potential sensitivity of findings to the choice of welfare measure. The results also point at the need for more careful research on how different dimensions of SES are related, and on the pathways by which the respective different dimensions impact on health related variables. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Measuring income related inequality in health: standardisation and the partial concentration index

HEALTH ECONOMICS, Issue 10 2003
Hugh Gravelle
Abstract The partial concentration index (PCI) is commonly used as a measure of income related inequality in health after removing the effects of standardising variables such as age and gender which affect health, are correlated with income, but not amenable to policy. Both direct and indirect standardisation have been used to remove the effects of standardising variables. The paper shows that with individual level data direct standardisation is possible using the coefficients from a linear regression of health on income and the standardising variables and yields a consistent estimate of the PCI. Indirect standardisation estimates the effects of the standardising variables on health from a health regression which excludes income. The coefficients on the standardising variables include some of the effects of income on health if income is correlated with the standardising variables. Using these coefficients to remove the effects of the standardising variables also removes some of the effect of income on health and leads to an inconsistent estimate of the PCI. Indirect standardisation underestimates the PCI irrespective of the signs of the correlations of standardising variables and income with each other and with health. An adaptation of the PCI when the marginal effect of income on health depends on the standardising variables is also proposed. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Star formation in close pairs selected from the Sloan Digital Sky Survey

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2004
B. Nikolic
ABSTRACT The effect of galaxy interactions on star formation has been investigated using Data Release One of the Sloan Digital Sky Survey (SDSS). Both the imaging and spectroscopy data products have been used to construct a catalogue of nearest companions to a volume-limited (0.03 < z < 0.1) sample of galaxies drawn from the main galaxy sample of SDSS. Of the 13 973 galaxies in the volume-limited sample, we have identified 12 492 systems with companions at projected separations less than 300 kpc. Star formation rates for the volume-limited sample have been calculated from extinction and aperture corrected H, luminosities and, where available, IRAS data. Specific star formation rates were calculated by estimating galaxy masses from z -band luminosities, and r -band concentration indices were used as an indicator of morphological class. The mean specific star formation rate is significantly enhanced for projected separations less than 30 kpc. For late-type galaxies, the correlation extends out to projected separations of 300 kpc and is most pronounced in actively star-forming systems. The specific star formation rate is observed to decrease with increasing recessional velocity difference, but the magnitude of this effect is small compared to that associated with the projected separation. We also observe a tight relationship between the concentration index and pair separation; the mean concentration index is largest for pairs with separations of approximately 75 kpc and declines rapidly for separations smaller than this. This is interpreted as being due to the presence of tidally triggered nuclear starbursts in close pairs. Further, we find no dependence of star formation enhancement on the morphological type or mass of the companion galaxy. [source]

Specific gravity as an alternative to creatinine for estimating urine concentration in captive and wild chimpanzee (Pan troglodytes) Samples

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009
Stephanie F. Anestis
Abstract The measurement of hormones in urine has become a widely used technique in primatology. Because urine concentration varies according to fluid intake, concentration must be measured in each sample collected, and hormone values are always expressed per unit of concentration. Traditionally, creatinine has been used as a concentration index, but some studies in humans have shown that creatinine varies among populations and even within and between individuals within a population, and that it begins to degrade after just one freeze,thaw cycle. In addition, creatinine measurement is relatively time-consuming and expensive and creates hazardous waste. In this study, we tested the hypothesis that specific gravity, or the ratio of the density of a sample to that of water, is highly correlated with creatinine measurement in urine samples collected from captive chimpanzees at the New Iberia Research Center in Louisiana and wild chimpanzees at the Ngogo study site in the Kibale National Park, Uganda. We found that specific gravity and creatinine were highly correlated in both captive (N=124) and wild (N=13) chimpanzee samples, and that specific gravity measurement was robust to actual and simulated transport conditions and repeated freeze,thaw cycles. We recommend that researchers consider specific gravity measurement as a preferable alternative to creatinine measurement in their studies of primate endocrinology. Am. J. Primatol. 71:130,135, 2009. © 2008 Wiley-Liss, Inc. [source]

Comparisons of the environmental dependence of galaxy properties between blue late-types and red late-types

ASTRONOMISCHE NACHRICHTEN, Issue 7 2010
X.F. Deng
Abstract Using the volume-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6), we investigate the difference of the environmental dependence of galaxy properties between blue late-types and red late-types, and find that the galaxy luminosity and concentration index are almost independent of the local density in the two samples. We also note a strong correlation between g , r color and the environment in the red late-type sample, while this correlation is very weak in the blue late-type sample (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Explaining the differences in income-related health inequalities across European countries

HEALTH ECONOMICS, Issue 7 2004
Eddy van Doorslaer
Abstract This paper provides new evidence on the sources of differences in the degree of income-related inequalities in self-assessed health in 13 European Union member states. It goes beyond earlier work by measuring health using an interval regression approach to compute concentration indices and by decomposing inequality into its determining factors. New and more comparable data were used, taken from the 1996 wave of the European Community Household Panel. Significant inequalities in health (utility) favouring the higher income groups emerge in all countries, but are particularly high in Portugal and , to a lesser extent , in the UK and in Denmark. By contrast, relatively low health inequality is observed in the Netherlands and Germany, and also in Italy, Belgium, Spain Austria and Ireland. There is a positive correlation with income inequality per se but the relationship is weaker than in previous research. Health inequality is not merely a reflection of income inequality. A decomposition analysis shows that the (partial) income elasticities of the explanatory variables are generally more important than their unequal distribution by income in explaining the cross-country differences in income-related health inequality. Especially the relative health and income position of non-working Europeans like the retired and disabled explains a great deal of ,excess inequality'. We also find a substantial contribution of regional health disparities to socio-economic inequalities, primarily in the Southern European countries. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Measuring inequality in self-reported health,discussion of a recently suggested approach using Finnish data

HEALTH ECONOMICS, Issue 7 2004
Jorgen Lauridsen
Health surveys often include a general question on self-assessed health (SAH), usually measured on an ordinal scale with three to five response categories, from ,very poor' or ,poor' to ,very good' or ,excellent'. This paper assesses the scaling of responses on the SAH question. It compares alternative procedures designed to impose cardinality on the ordinal responses. These include OLS, ordered probit and interval regression approaches. The cardinal measures of health are used to compute and decompose concentration indices for income-related inequality in health. Results are provided using Finnish data on 15D and the SAH questions. Further evidence emerges for the internal validity of a method used in a pioneering study by van Doorslaer and Jones which was based on Canadian data on the McMaster Health Utility Index Mark III (HUI) and SAH. The study validates the conclusions drawn by van Doorslaer and Jones. It confirms that the interval regression approach is superior to OLS and ordered probit regression in assessing health inequality. However, regarding the choice of scaling instrument, it is concluded that the scaling of SAH categories and, consequently, the measured degree of inequality, are sensitive to characteristics of the chosen scaling instrument. Copyright © 2003 John Wiley & Sons, Ltd. [source]