Horizontal inequity in access to healthcare services and educational level in Spain

Abstract

The aim of this study is to measure horizontal equity in the use of healthcare services in Spain, proposing two methodological innovations. First by defending it as equality of access for equal need, irrespective of educational level, unlike the prevailing methodological approach to horizontal equity which relates it to income. Second, by estimating it by means of the slope index of the inequality of characteristics, analagous to the inequity index proposed by Kakwani, Wagstaff and van Doorslaer (1997; HIWV) but presenting some methodological advantages, the greater robustness of the data available on educational level than of those on income, and the possibility of isolating the net effect of the educational level on the use of healthcare by controlling for other variables. The methodology is designed in three parts: (1) estimation of the relationship between the educational level and the use of healthcare services by means of a model of the likelihood of demand for healthcare services, commonly used in the literature; (2) estimation of the relationship between educational level and health by approximating a production function of individuals' health according to their personal characteristics and other factors conditioning health; and (3) estimation of the slope index of inequality as a measure of horizontal inequity, using educational level instead of income as the criterion for ranking individuals. The data base used was a sample of 55,598 observations from the Survey of disabilities, handicaps and state of health of 1999, carried out in Spain. No significant statistical association was found between educational level and use of healthcare services. On the other hand, the relationship between educational level and health, with the three proxy variables used (perception of health, days of limitation and number of chronic illnesses) shows a positive correlation, i.e. an increase in educational level is associated with a greater probability of enjoying better health. Horizontal inequity, measured by the proposed slope index of inequality, gives a range of statistically significant values between 13.91% and 9.40%, depending on cases, i.e. the significant inverse relationship between state of health and educational level is not reflected proportionally in healthcare use, implying that, with greater need, the access of individuals with a lower educational level to public healthcare services is the same as for the rest. These results suggest that the educational level may be a variable to consider when characterizing the healthcare needs of a population in a defined geographical area, at least from the normative characterization of horizontal equity proposed.