The concentration index of a binary outcome revisited

The binary variable is one of the most common types of variables in the analysis of income-related health inequalities. I argue that while the binary variable has some unusual properties, it shares many of the properties of the ratio-scale variable and hence lends itself to both relative and absolute inequality analyses, albeit with some qualifications. I argue that criticisms of the normalization I proposed in an earlier paper, and of the use of the binary variable for inequality analysis, stem from a misrepresentation of the properties of the binary variable, as well as a switch of focus away from relative inequality to absolute inequality. I concede that my normalization is not uncontentious, but, in a way, that has not previously been noted.     

On the interpretation of a concentration index of inequality

This paper aims to add a more intuitive understanding to the concept of a concentration index for measuring relative inequality with an application of health-related measures by income. A new redistribution interpretation and an existing redistribution interpretation of the Gini are presented and applied to the concentration index. Both indicate the share of the total amount of any variable that needs redistributing in a particular way from rich to poor (or vice versa) to achieve a concentration index equal to zero. The characteristics of these redistribution schemes are compared. The paper also draws attention to the relationship between a concentration index, a correlation coefficient with relative income rank and a coefficient of variation of the variable of interest. These relationships are illustrated using data on inequality in dental care utilisation in European countries taken from the European Community Household Panel survey.     

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

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.     

A note on the decomposition of the health concentration index

In recent work, the concentration index has been widely used as a measure of income-related health inequality. The purpose of this note is to illustrate two different methods for decomposing the overall health concentration index using data collected from a Short Form (SF-36) survey of the general Australian population conducted in 1995. For simplicity, we focus on the physical functioning scale of the SF-36. Firstly we examine decomposition 'by component' by separating the concentration index for the physical functioning scale into the ten items on which it is based. The results show that the items contribute differently to the overall inequality measure, i.e. two of the items contributed 13% and 5%, respectively, to the overall measure. Second, to illustrate the 'by subgroup' method we decompose the concentration index by employment status. This involves separating the population into two groups: individuals currently in employment; and individuals not currently employed. We find that the inequality between these groups is about five times greater than the inequality within each group. These methods provide insights into the nature of inequality that can be used to inform policy design to reduce income related health inequalities.     

The association of major depressive episodes with income inequality and the human development index

The aim of this study was to estimate the association between country income distribution and human development with the 12-month occurrence of major depressive episodes across countries. A total of 251,158 people surveyed by the World Health Organization from 2002 to 2003 from 65 countries were included in the study. The survey contained items for identifying major depressive episodes (MDE) in the previous 12 months, attained education (used as an indicator of individual socioeconomic status) and other demographic information. Income inequality was measured with the Gini index, a national-level indicator; the United Nations human development index (HDI) measured overall country development. Country-level and multilevel linear regression models were utilized to study the associations. We found that moderately developed countries had the lowest adjusted prevalence of MDE followed by high and low developed countries. The Gini index was positively associated with major depressive episodes, but only among high HDI countries. After adjusting for age, gender, marital status, education and HDI, the multilevel prevalence ratio indicated a 4% increase in risk of MDE for a person living in a country associated with a 1% increment in income equality. This finding means, for example, that comparing two highly developed countries, one with low income inequality (Gini=0.25) with another with high income inequality (Gini=0.39), one would expect to see an increase in the prevalence of MDE from 4.0% to 6.2%. These findings raise important questions about the role of income inequality on social forces that can lead to depression.     

我国居民与收入相关的健康不平等实证研究

本文利用中国健康与营养调查（CHNS）2006年的调查数据，从定量的角度对我国居民与收入相关的健康不平等进行了分析。本文利用有序Probit模型获得了自评健康数据背后的实际健康得分，在此基础上计算健康集中指数衡量我国居民与收入相关的健康不平等程度。结果表明，我国居民的健康不平等问题较为严重，健康不平等问题在城乡之间和不同经济发展水平地区之间存在着较大的差别。     

Extending decomposition analysis to account for unobserved heterogeneity and persistence in health behavior: Income‐related smoking inequality among Swedish women

This article suggests an enrichment of the standard method for decomposition of the concentration index to account for unobserved heterogeneity and persistence in health behavior. As the underlying regression model in the decomposition, this approach uses a dynamic random‐effect probit that both consider individual heterogeneity, using a Mundlak type of specification, and applies a simple solution to account for smoking persistence. I illustrate the suggested approach using a panel of Swedish women in Statistics Sweden's Survey of Living Conditions for one vital health‐related behavior, smoking. The results highlight the importance of persistence and show that education and living in a single household are the main drivers of income‐related smoking inequality.     

Model for competition from self during passive immunization, with application to broadly neutralizing antibodies for HIV

We propose a mathematical model to interpret observations concerning the behavior of broadly neutralizing antibodies for chronic HIV in vivo. The model enables us to identify a threshold antibody level that must be achieved to decrease the viral load effectively. Although this threshold has not been reached in existing passive immunization studies, it is within range of humoral immune responses, suggesting that therapeutic vaccines are feasible. In an appendix, we develop a model of passive immunization against influenza, and acute infection.     

Agreement with inequality axioms and perceptions of inequality among environmental justice and risk assessment professionals

Quantitative measures of inequality are commonly used when evaluating income inequality and have gained increasing importance in evaluating distributions of environmental and other health risks. However, there have been few attempts to determine whether the theoretical underpinnings of these measures are supported empirically, especially among individuals who may be end users of the information, and whether considerations differ for health risks and income. In this study, we administered surveys to 160 environmental justice and risk assessment professionals to identify adherence to standard inequality axioms for questions framed around both health and income. To better understand beliefs and relative priorities placed on inequality, we also assessed preferences for utilitarian, egalitarian or prioritarian methods of resource distribution, and willingness to trade efficiency for equality. A majority of respondents did not support key axioms that underlie common inequality indicators, believing that uniform proportional increases in income or health would increase inequality and rejecting the Pigou-Dalton transfer principle (which states that inequality should decrease when transfers are made from a better-off to a worse-off person) under certain circumstances. Environmental justice professionals had significantly stronger egalitarianism preferences than risk assessment professionals (p = 0.02), while respondents expressed greater utilitarian tendencies when questions were framed as health rather than income inequality (p = 0.08). Our findings indicate that concepts of inequality may not be aligned with commonly utilised quantitative indicators and that different stakeholders may perceive inequality differently, emphasizing the need for explicit communication about the interpretation of quantitative inequality measures in health risk assessment.     

The uptake of childhood immunization and financial incentives to general practitioners

Among the target-linked services introduced by the 1990 general practitioners' contract, childhood immunization in Scotland is the best suited for GPs to achieve the high target, given a centralized call and recall system and public confidence in the service. Yet over 25% of the practices in the area of the Greater Glasgow Health Board did not qualify for the high target payments in the last quarter of the 1991/92 financial year. Examining indicators of the socioeconomic characteristics of the patient population, practice profiles and the effect of financial incentives, we discuss the reasons for cross-practice variation in the uptake of this service and estimate the probability of practices which missed the high target achieving it in the future.     

Socio-economic inequality in preterm birth: a comparative study of the Nordic countries from 1981 to 2000

During the 1980s and 1990s, there were large social and structural changes within the Nordic countries. Here we examine time changes in risks of preterm birth by maternal educational attainment in Denmark, Finland, Norway and Sweden. Information on gestational age and maternal socio-economic position was obtained from the NorCHASE database, which includes comparable population-based register data of births from Denmark, Finland, Sweden and Norway from 1981 to 2000. The risks of very preterm birth (<32 gestational weeks) and moderately preterm birth (32–36 gestational weeks) were calculated by maternal educational attainment and analysed in 5-year intervals from 1981 to 2000.
Compared with mothers with >12 years of education, mothers with <10 years of education had similarly increased risks of very, and to a lesser extent moderately, preterm birth in all four countries. The educational gradient increased slightly over time in very preterm births in Denmark, while there was a slight narrowing of the gap in Sweden. In moderately preterm births, the educational inequality gap was constant over the study period in Denmark, Norway and Sweden, but narrowed in Finland. The educational gradient in preterm birth remained broadly stable from 1981 to 2000 in all four countries. Consequently, the socio-economic inequalities in preterm birth were not strongly influenced by structural changes during the period.     

四川省科学城辖区流动儿童预防接种状况调查分析

目的了解科学城辖区流动儿童分布及预防接种状况。方法采取横断面调查方法,对辖区2岁~14岁在托或就学流动儿童的免疫状况进行调查,对调查结果进行描述和分析。结果流动儿童1295人,户籍所在地主要是本市及各区县,建证率、五苗全程免疫覆盖率分别为88.26%、82.01%,五苗中乙肝疫苗(HepB)接种完成率最低,为82.93%,口服脊髓灰质炎疫苗(OPV)、白百破联合疫苗(DPT)、麻疹(MV)加强(复种)免疫率分别为81.06%、84.79%、86.25%,百白破疫苗(DT)接种率为64.08%。户籍不同地区儿童的建证率、四苗全程覆盖率有显著差异(χ2=9.32、20.85,P(0.05)。结论提高流动儿童预防接种率需多部门合作,通过入托、入学查验预防接种证以确保所有儿童完成全程接种。全国各地应尽快实现城乡儿童预防接种信息管理系统建设,实现接种信息共享,以消除由于接种证丢失造成的假性免疫空白。     

Delivery to the lower respiratory tract is required for effective immunization with Newcastle disease virus-vectored vaccines intended for humans

Newcastle disease virus (NDV), an avian virus, is being evaluated for the development of vectored human vaccines against emerging pathogens. Previous studies of NDV-vectored vaccines in a mouse model suggested their potency after delivery by injection or by the intranasal route. We compared the efficacy of various routes of delivery of NDV-vectored vaccines in a non-human primate model. While delivery of an NDV-vectored vaccine by the combined intranasal/intratracheal route elicited protective immune responses, delivery by the subcutaneous route or the intranasal route alone elicited limited or no protective immune responses, suggesting the necessity for vaccine delivery to the lower respiratory tract. Furthermore, direct comparison of a vaccine based on an NDV mesogenic strain (NDV-BC) with a similarly designed NDV vector based on a modified lentogenic strain carrying a polybasic F cleavage site (NDV-VF) suggested that the two NDV strains were similar in immunogenicity and were equally protective.     

Economic globalization,inequality and body mass index: a cross-national analysis of 127 countries

This article investigates to what extent the worldwide increase in body mass index (BMI) has been affected by economic globalization and inequality. We used time-series and longitudinal cross-national analysis of 127 countries from 1980 to 2008. Data on mean adult BMI were obtained from the Global Burden of Metabolic Risk Factors of Chronic Diseases Collaborating Group. Globalization was measured using the Swiss Economic Institute (KOF) index of economic globalization. Economic inequality between countries was measured with the mean difference in gross domestic product per capita purchasing power parity in international dollars. Economic inequality within countries was measured using the Gini index from the Standardized World Income Inequality Database. Other covariates including poverty, population size, urban population, openness to trade and foreign direct investment were taken from the World Development Indicators (WDI) database. Time-series regression analyses showed that the global increase in BMI is positively associated with both the index of economic globalization and inequality between countries, after adjustment for covariates. Longitudinal panel data analyses showed that the association between economic globalization and BMI is robust after controlling for all covariates and using different estimators. The association between economic inequality within countries and BMI, however, was significant only among high-income nations. More research is needed to study the pathways between economic globalization and BMI. These findings, however, contribute to explaining how contemporary globalization can be reformed to promote better health and control the global obesity epidemic.     

社会医疗保险缓解了未成年人健康不平等吗

  目的  了解0～3岁儿童照顾模式与健康不平等的关系,为促进儿童健康发展提供参考依据。  方法   收集中国家庭追踪调查（CFPS）2018年全国数据,从中抽取1 837名0～3岁儿童,采用集中指数与分解的方法测量儿童健康不平等状况及相关贡献因素,重点分析照顾模式对儿童健康不平等的贡献。  结果  全国0～3岁儿童健康不平等指数为0.039,表明我国存在与社会经济地位相关的儿童健康不平等,来自高收入家庭的儿童普遍健康状况更好。儿童健康集中指数分解结果显示,隔代抚养与混合抚养对0～3岁儿童健康不平等的贡献率分别为4.99 %和8.04 %,一定程度造成了不平等。儿童的家庭规模（53.98 %）、年均家庭收入（38.81 %）和父亲的健康状况（23.63 %）是对儿童健康不平等贡献最大的3个要素。医疗保险和母乳喂养时长对儿童健康不平等的贡献率分别为 – 6.36 %和 – 7.56 %,有助于缩小儿童健康不平等。  结论  儿童照顾模式及相关家庭因素均对0～3岁儿童的健康有重要影响,并会造成儿童健康的不平等,应注意规避相关危险因素。     

Cost analysis of supplemental immunization activities to deliver measles immunization to children in Anambra state,south-east Nigeria

BackgroundMeasles immunization is critical for reducing the societal burden of the disease, especially among children. However, the costs of the measles supplemental immunization activities, which are the main vaccine deployment strategy, are usually high and financing such immunization activities is a serious challenge in Nigeria. In Nigeria, little or no information exists on the costs of measles supplemental immunization activity for planning and sustenance of immunization programmes. This study aimed to determine the cost per child immunized and cost structure of a follow-up supplemental immunization activity (SIA) for measles immunization to children.MethodData on costs and outputs of SIA were collected from six Local Government area (LGAs) immunization offices in Anambra state, southeast Nigeria. The ingredient approach was used for costing, based on the providers’ perspective. The sample results were extrapolated to state estimates using volume weighted mean method. The major indicator considered was cost per child immunized. Two-way sensitivity analysis was used to test the robustness of the results.ResultThe cost per child immunized through SIA was $1.37 and the cost per child for operational cost only was $0.81. The total cost of the SIA for the sample was $345,069.35 and the operational cost was $204,969.46. The cost of personnel (43.99%) and vaccine (36.22%) contributed the highest percentage to the total cost of SIA. The cost of personnel and transportation took the first (74.6%) and second (7.10%) highest percentages of the operational cost for the sample. The estimated total and operational costs of measles SIA for the state were $1,279,127.84 and $759,795.52 respectively.ConclusionThe cost per child immunized with measles containing vaccine through SIA is relatively high in Nigeria. There is a need to review the activities with SIA, so as to ensure that resources are efficiently allocated and used for different activities of the programme.     

Income-related inequality in the distribution of obesity among Europeans

Aim  The current study concentrates on the issue of income related inequality in obesity for the case of European Union, an association, which has not been thoroughly examined in the literature. Subjects and methods  Ten European countries for a period of 4 consecutive years (1998–2001) are under consideration, with the information deriving from the “European Community Household Panel” (ECHP) dataset. In order to elaborate on the above association, the concentration index was selected as a means for measuring quantitatively the degree of inequality. Furthermore, an alternative method was introduced, known as the “indirect standardization method,” so as to examine if the observed level of inequality was over-reported. Results  Treating the European Union as a whole, income inequality in obesity appears to be a burden for the less affluent. Investigation of each country separately reveals that inequality is of most importance for the female population, and especially for the middle-aged one, while no clear association was found for the males. Furthermore, negligence to adjust the models for the education level and the employment status could lead to an over-estimation of the inequality in obesity. Conclusion  Our primary results attest to the existing literature, showing that a BMI with a value greater than 30 is most likely to be an encumbrance for those of low socioeconomic profiles. However, the extent of inequality in the European Union is found to be low. Effective preventive policies should address the low socioeconomic status female population in Europe, and special attention should be given to the middle-aged.     

河北省2010—2018年含麻成分疫苗补充免疫疑似预防接种异常反应监测分析

目的 了解河北省2010—2018年含麻成分疫苗(measles-containing vaccine, MCV)补充免疫活动中疑似预防接种异常反应(adverse events following immunization, AEFI)特征,为及时妥善处置补充免疫活动中发生的不良反应提供科学依据。 方法 通过全国AEFI信息管理系统和各市专项上报的MCV补充免疫接种数据,对河北省2010—2018年MCV补充免疫活动中AEFI监测数据进行描述流行病学分析。 结果 河北省2010—2018年MCV补充免疫共报告AEFI个案2 590例,总报告发生率为64.40/10万剂;男性略多于女性,年龄主要集中在0～6岁的儿童。不良反应报告发生率为63.10/10万剂,其中,一般反应为54.03/10万剂、异常反应为9.08/10万剂。62.19%的异常反应临床诊断为过敏反应导致的皮疹。严重异常反应报告发生率为3.18/10万剂。不良反应主要发生在接种后1 d内。 结论 河北省2010—2018年MCV补充免疫的AEFI病例以一般反应为主。异常反应以过敏导致的皮疹类为主,严重异常反应报告发生率未见明显升高。     

Associations of economic and gender inequality with global obesity prevalence: understanding the female excess

Obesity is widely assumed to be associated with economic affluence; it has therefore been assumed to become more common with economic development. However, obesity has also been associated with poverty. These contrary findings highlight the need for an examination of the contribution of social and economic factors to the global distribution of obesity. Males and females may be differently exposed to social and economic inequality, however few studies have considered possible gender differences in the association between socio-economic indices and obesity prevalence. We analysed between-country associations between obesity prevalence and three social or economic indices: per capita gross domestic product (GDP), the Gini index of national wealth inequality, and the gender inequality index (GII). We considered the genders separately, the gender average, and also the gender difference (female excess) in obesity prevalence. Across 68 countries listing sample size, there were 3 obese women for every 2 obese men. Within populations, obesity prevalence in males and females was strongly correlated (r = 0.74), however, only 17% of the female excess prevalence was accounted for by the gender-average prevalence. In both genders, there was a positive association between obesity prevalence and GDP that attenuated at higher GDP levels, with this association weaker in females than males. Adjusting for GDP, both the Gini index and GII were associated with excess female obesity. These analyses highlight significant gender differences in the global distribution of obesity, and a gender difference in the association of obesity prevalence with socio-economic factors. The magnitude of female excess obesity is not constant across populations, and is greater in countries characterised by gender inequality and lower GDP. These findings indicate that improving women’s status may be a key area for addressing the global obesity epidemic over the long term, with potential benefits for the women themselves and for their offspring.     

国外预防接种服务及对我国农村地区的启示

预防接种被认为是经济、有效、方便的提高易感人群免疫水平及预防传染性疾病的公共卫生干预措施.目前,我国预防接种工作,尤其是农村地区的免疫接种率有所下降,有些传染病有死灰复燃的趋势.该文通过对几个国家预防接种服务特点和经验的介绍,试图总结出我国农村地区预防接种服务存在的问题,并借鉴其他国家的经验提出相关政策建议.