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Socioeconomic gradients in self-rated health: a developing country case study of Enugu State, Nigeria

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Abstract

The use of self-rated health (SRH) as an indicator of health has generally been limited to the study of socioeconomic inequalities in industrialized societies. We evaluate the potential usefulness of this indicator in a developing country context using a data set generated from Enugu State, Nigeria, which includes information on SRH and health status index (HSI). We also evaluate the difference in the estimated socioeconomic inequality in health using two specifications of the concentration index: the standard specification and Erreygers (J Health Econ, 28:504–515, 2009a) specification. The results show that self rated health is a potentially useful indicator of health state for populations in developing countries. Our tentative results indicates that the Erreygers (J Health Econ 28:521–524, 2009b) specification of the concentration index detects larger levels of inequality than the standard specification, and thus raises questions for researchers who use results obtained from the instrument for policy advice. The simulation results also show that the level of social aversion to socio-economic differences among people would generally increase the perceived level of health inequality in a population.

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Notes

  1. See, for example, van Doorslaer and Gerdtham (2003), Crossley and Kennedy (2002), Huisman et al. (2007), Silventoinen and Lahelma (2002), Kunst et al. (2005), Singh-Manoux et al. (2006), Mackenbach et al. (2002), Power et al. (1996), Wannamethhee and Shaper (1991), van Dooslaer and Jones (2003a, b), van Dooslaer and Koolman (2004), among others.

  2. Gilbert and Soskolne (2003) which studied inequality in SRH in Soweto, South Africa, is the only exception known to us.

  3. We tried as much as possible to overcome this defect in the study by introducing an ethically flexible parameter of inequality aversion. This allows for the policy-maker’s level of aversion to inequality in the distribution.

  4. Lorenz curve plots the cumulative proportion of the variable of interest on the y-axis and the cumulative proportion of the population ranked from the least advantaged to the most advantaged on the x-axis.

  5. The Gini index likewise the concentration index when applied to health, have the attraction that they can be decomposed by factors. This property makes it possible for the use of linear regression decomposition technique to decompose these indices into the contributions of different explanatory variables.

  6. In Atkinson-type utilitarian social welfare function what is important is not the rank of the individual in the distribution but the aggregate utility.

  7. This is consistent with the general population census figures (National Population Commission 2000) which shows that Enugu state has greater female population that males.

  8. While this optimism is generally acknowledged in the literature in developing countries, it is not clear that the same phenomenon occurs in developed countries. If it does, it would seem to suggest that SRH may have systematic errors in estimating health inequalities generally which would cast doubt on its validity as instrument for measuring health inequalities. However, if this phenomenon is peculiar to developing country populations with huge social inequalities, it may limit the scope of comparison between inequalities in SRH in developed and developing country populations.

  9. This behaviour is partly explained in terms of the high opportunity cost of ill-health to poor people as they cannot ‘afford’ to be ill particularly at certain seasons of the year or because they have poorer access to health services (Ataguba and McIntyre 2009).

  10. We are grateful to an anonymous reviewer who pointed this problem out to us.

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Acknowledgments

The authors would like to thank the editor in chief and two anonymous reviewers for very helpful comments, suggestions and technical inputs that helped greatly to improve the quality of our paper. In fact, we owe much gratitude to the first reviewer for his/her very detailed comments, suggestions and guidance. We are equally grateful to Jean-Yves Duclos for his technical inputs into the PEP research work from which this paper is derived.

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Authors and Affiliations

  1. Health/Environmental Economics Units, Department of Economics, University of Nigeria, Nsukka, Enugu State, Nigeria

    H. Eme Ichoku & William M. Fonta

  2. Health Economics Unit, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa

    H. Eme Ichoku & Michael Thiede

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  1. H. Eme Ichoku
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  2. William M. Fonta
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Correspondence to William M. Fonta.

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Eme Ichoku, H., Fonta, W.M. & Thiede, M. Socioeconomic gradients in self-rated health: a developing country case study of Enugu State, Nigeria. Econ Change Restruct 44, 179–202 (2011). https://doi.org/10.1007/s10644-010-9098-0

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