Highly active antiretroviral therapy and socioeconomic inequalities in AIDS mortality in Spain.

In a recent paper, Borrell et al. document the change in AIDS mortality following the introduction of highly active antiretroviral therapy (HAART) in Spain. Because access to HAART is free under Spain’s National Health Service, the authors hypothesized that the introduction of HAART would narrow existing socioeconomic (SES) inequalities in AIDS mortality. They compare the ratio of age-adjusted mortality rates among lower and higher socioeconomic groups over time and, based on the increases in the ratio over time among men and women, conclude that ‘SES group related inequalities in AIDS mortality did not narrow after the introduction of HAART’ (p. 607). However, judgments about the magnitude of health inequalities often depend on the scale upon which they are measured, especially over time. And it is obvious from their Figures 1 and 2 that if one uses the arithmetic difference in mortality rates, rather than the ratio, SES inequalities have indeed narrowed, and by a large amount. Moreover, the spectacular decline in mortality among low-educated individuals living in deprived neighbourhoods suggests that these individuals have, in fact, benefited most from the introduction of HAART. This is consistent with other evidence suggesting that sicker populations (i.e. those most in need of treatment) derive greater benefits from HAART. To be fair, Borrell et al. do not completely ignore absolute changes, noting that ‘it has to be mentioned that absolute differences are higher in 1995 than in the other years, mainly due to the higher rates’ (pp. 603–604). But it is unclear why they do not consider absolute SES mortality differences as inequalities, and they do not provide any justification for why we should privilege the relative over the absolute perspective. Given that most countries now have some public health policy focus on reducing health inequalities, it remains important to measure and monitor health inequality trends, especially in response to medical innovations such as HAART. Thus, the analysis by Borrell et al. is most welcome and we would generally agree with their conclusion that current SES inequalities in AIDS mortality in Spain are likely to be driven by some combination of lower access and adherence to treatment (including HAART), cormorbid conditions, and material factors. Thus an absolute perspective on inequalities may not, in this case, result in substantially different strategies for further reducing inequalities in AIDS mortality in Spain. But taking an absolute perspective does suggest that HAART has been extremely important in narrowing socioeconomic differences in AIDS mortality in Spain.