It depends on the question you are trying to answer. If you are considering the question in the context of health, it will depend on whether you are you looking pure health inequality or socioeconomic health inequality.

Equity is considered as a social issue. Normally, we used Lorenz curve as well as Gini-coefficient for evaluating the socio-economic status. The equity is comprehensive term, when we attempt to evaluate it, first of all we should define its dimensions. Often. SES is considered as education, occupation and income. But equity concerns to the distribution of resources as well. Hence, looking to the distribution of resources among people, to some extent we can quantify and evaluate it. Evaluation of the equity in term of income, Lorenz curve and Gini cofficient may best ....    mostly we we concentration curve in clinical research.

You can use Gini to look at the distribution of health but you would be measuring pure health inequality and not socioeconomic health inequality. The difference between the Lorenz curve and the concentration curve resides in what you are using as a ranking variable. In the Lorenz Curve you will rank people according to their health whereas when you use the Concentration Curve you will rank people according to their socioeconomic status...

I tend to agree with Yazbeck in this matter.Yes you can use the lorenz curve, but that will be measuring purely health inequality and not SE inequality. Thus, if you are concerned about the distribution of the health variable according to the ranking of a certain socio-economic variable say income or assets, then you are better of with the concentration index.

 If you need to evaluate the inequity in the distribution of any health condition the best option is the concentration index. 

Thank you all of the contributors.

The Lorenz curve and the Gini-coefficient are used to evaluate equity in the distribution of health or income in a population. If you are interested in evaluating equity in the distribution of health outcomes between groups of patients, other approaches can be more consistent. Firstly, you must define what definition of equity are you going to use. Second, you must indicate the equity question you are going to study.

Dear all commentators,

Thank you for taking interest in the topic. I am interested to evaluate the out of pocket payment of neonatal health care against capacity to pay of the households. From the discussion, May I conclude that the Lorenz curve and index be graphed and calculated ?

Adhikari,

If I understand your recent question, then it seems to me that OOP for neonatal health is the outcome and the (socio-economic) determinant is "capacity to pay of households". In this case, as has been correctly highlighted above, I would suggest that you use the concentration index/curve approach because you have an outcome and social ranking mechanism (the capacity yo pay). You may want to remember the relationship between the concentration index/curve theory with the socio-determinants of health theories.

http://www.worldbank.org/en/topic/health/publication/analyzing-health-equity-using-household-survey-data

Dear All

Thank you for your concerns. My interest is to measure health from SE lenses, I agree to all claiming this (concentration index), but can it be rendered with the help of simple software; other than R computing; such as excel, or epi, or spss, or such?

In health economics ,Lorenz Curve shows the proportion of the income distribution allocated for the poorest households but Concentration Curve assess the degree of income related inequality in the distribution of health variable.