Global income-related inequalities in HIV testing.

BACKGROUND Voluntary counseling and testing (VCT) is an important prevention initiative in reducing HIV/AIDS transmission. Despite current global prevention efforts, many low- and middle-income countries continue reporting low VCT levels. Little is known about the association of within- and between-country socioeconomic inequalities and VCT. Based on the 'inverse equity hypothesis,' this study examines the degree to which low socioeconomic groups in developing countries are disadvantaged in VCT. METHODS Using recently released data from the 2002 to 2003 World Health Survey (WHS) for 106 705 individuals in 49 countries, this study used multilevel logistic regression to examine the association of individual- and national-level factors with VCT, and whether national economic development moderated the association between individual income and VCT. Individual income was based on country-specific income quintiles. National economic development was based on national gross domestic product per capita (GDP/c). Effect modification was evaluated with the likelihood ratio test (G(2)). Individuals eligible for the VCT question of the WHS were adults between the ages of 18-49 years; women who had given birth in the last 2 years were excluded from this question. RESULTS VCT was more likely among higher income quintiles and in countries with higher GDP/c. GDP/c moderated the association between individual income and VCT whereby relative income differences in VCT were greater in countries with lower GDP/c (G(2)= 9.21; P= 0.002). Individual socio-demographic characteristics were also associated with the likelihood of a person having VCT. CONCLUSIONS Relative socioeconomic inequalities in VCT coverage appear to decline when higher SES groups reach a certain level of coverage. These findings suggest that changes to international VCT programs may be necessary to moderate the relative VCT differences between high- and low-income individuals in lower GDP/c nations.