Chapter 6: Interpreting the Tables and Graphs
The table also shows the average prevalence in the whole population, which amounts to 3.29, 11.36, and 6.03 percent for limitations in hearing, seeing, and walking, respectively. The concentration index for hearing is moderately negative ( 0.0583), which reflects the decrease in health conditions with income. In contrast, the concentration index for seeing impairment is clearly positive (0.1096) as a result of the increase in prevalence with income. Finally, the concentration index for walking (0.0147) is close to 0, which indicates near independence between this health condition and income. When aversion to inequality is increased, the weight of the first quintiles is increased relative to the richest quintiles. Since the first quintiles have a higher prevalence of hearing impairment, the corresponding extended concentration index gets farther into the negatives. The opposite is true for seeing impairment, and the extended concentration index for walking impairment is barely affected by change in inequality aversion. Finally, the achievement index amounts to 0.0348, 0.1012, and 0.0594 for hearing, seeing, and walking impairment, respectively, when applying the standard concentration index weighting. These have to be compared with the nonweighted averages for the whole population. For instance, since the concentration index is positive in the case of seeing impairment, the relatively higher prevalence of the richest is underweighted, and, as a result, the achievement index (0.1012) indicates better health compared with average health (0.1136). When aversion to inequality is increased (that is, the last two lines of the table), the greater weight assigned to the first quintiles makes average health deteriorate slightly in the case of hearing (that is, higher average prevalence of hearing impairment). In contrast, as richer individuals suffer more from seeing impairment, higher aversion to inequality makes the achievement index improve for this condition (that is, lower average prevalence of seeing impairment).
Concentration of Health Utilization Concepts Graphs G1 and G2 present the concentration curve for each health outcome and for utilization of each health service analyzed, respectively. The curves represent the cumulative share of either health outcomes or utilization
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