Thirteen countries with complete information on prices, foreign assistance, and antiretroviral coverage from 2003 to 2008 were studied: Cameroon, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Nigeria, Rwanda, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe. These countries represent about 60% of Africa’s population and 84% of Africa’s estimated number of people living with HIV/AIDS.
In 2003 the mean annual price of first line antiretroviral therapy in the study countries was $1177 (SD $508) per capita and the average coverage of antiretroviral treatment was 5.7% (SD 4.6%). By 2008 the mean annual price of first line antiretroviral therapy had decreased to $96.1, with substantially less variability (SD $18.1). During the same period, antiretroviral coverage increased to 51.2% on average (SD 23.6%). National public health expenditures per capita increased from $23.7 in 2003 to $40.9 in 2008 (P=0.42), although those expenditures were less different when expressed as a percentage of gross domestic product (3.1% in 2003 and 3.4% in 2008, P=0.75). Table 1 shows the descriptive variables of the study countries.
Table 1 Descriptive variables of the 13 study countries, 2003-8
The unadjusted model relating price and foreign assistance to coverage shows a strong association of coverage with both variables. From 2003 to 2008, every $10 decrease in the price of first line antiretroviral therapy was associated with a 0.19% increase in coverage (95% confidence interval 0.14% to 0.25%, P<0.001). Figure 1 shows the association of annual price of first line antiretroviral therapy per capita in 2008 US dollars and antiretroviral coverage. Two important observations are notable: firstly, price reductions were associated with greater increases in antiretroviral coverage at lower prices and, secondly, the annual prices decreased only modestly and converged to a narrow range of prices between 2007 and 2008. The adjusted model includes a non-linear (squared) relation, with price and adjustments for HIV prevalence, per capita national public health expenditures, urban status, per capita gross domestic product, government effectiveness, country fixed effects, and year fixed effects. Using this model, price reductions had a changing association with antiretroviral coverage at different prices. At an annual price of $500, every $10 decrease in the price of antiretroviral therapy was associated with a 0.04% increase in coverage (95% confidence interval 0.02% to 0.06%, P=0.01), and at an annual price of $100, a $10 decrease was associated with a 0.16% increase in coverage (0.11% to 0.20%, P=0.01).
Fig 1Relation between price of first line antiretroviral therapy and coverage. Points represent country and year estimate of price of therapy in 2008 US dollars and antiretroviral coverage during that year. Markers are differentiated by year (more ...)
Foreign assistance for HIV was also closely associated with antiretroviral coverage. Each additional $1 per capita in foreign assistance was associated with a 1.4% increase in antiretroviral coverage (1.1% to 1.6%, P<0.001) in the unadjusted model and 1.0% (0.7% to 1.2%, P<0.001) in the adjusted model. Several adjusters were associated with increased coverage: per capita national public health expenditures, government effectiveness score, and HIV prevalence (non-significant trend). Figure 2 shows the association between foreign assistance and coverage, and table 2 shows the associations for the fully adjusted model.
Fig 2Relation between foreign assistance and coverage. Foreign assistance is in 2008 US dollars distributed for HIV by three major international donors (President’s Emergency Plan for AIDS Relief, Global Fund, and World Bank) per capita (more ...)
Table 2 Impact of price reductions, foreign assistance, and development and governance indicators on coverage of HIV treatment using antiretroviral drugs in 13 African countries
The foreign assistance required for universal coverage was estimated using the adjusted model by holding the values for all covariates other than assistance, fixed at their 2008 levels. Using this approach, at an annual price of $100 for first line antiretroviral therapy and current national public health expenditures, foreign assistance for HIV would have to be about $64 per capita to reach universal coverage. Among the study countries, only one (Namibia) approaches that level of expenditures. The total assistance required to reach universal coverage in the 13 study countries is estimated at $14.8bn. At an annual price of $100 for first line antiretroviral therapy and foreign assistance for HIV per capita at the 2008 mean ($13.8), the national public health expenditures associated with universal coverage are $109 per capita, nearly three times current levels. Figure 3 shows the calculated relation between foreign assistance and national public health expenditures associated with universal coverage at different price points. Price reductions alone without further increase in public health expenditures or foreign assistance for HIV were associated with a maximum coverage of 55.8% at an annual price of $1.
Fig 3Resource requirements for universal coverage. Combination of foreign assistance for HIV per capita and national public health expenditures estimated to be sufficient for universal coverage at difference price points of first line antiretroviral (more ...)
The portion of the increase in coverage explained by prices and assistance was estimated with a thought experiment: if everything remained at 2003 levels except for prices, what would the predicted coverage be in 2008? This was repeated for assistance, and the portion of the predicted increase in coverage with each was calculated. Using this approach prices were estimated to be associated with 20.4% of the predicted increase in coverage and foreign assistance with 29.1% of the increase.
Finally, the mortality benefits of price reductions and foreign assistance were calculated. Antiretroviral therapy in sub-Saharan Africa was estimated to prolong life by 4.0-12.1 years, and 4.8 million people were in need of antiretroviral therapy in the 13 study countries in 2006.26 36 37
Using the unadjusted model (to avoid non-linear relations), a $10 decline in the price of antiretroviral drugs was associated with 36
352 years of life saved. Using a similar calculation, each additional $1 per capita in foreign assistance for HIV ($480m for the total study population) was associated with 268
120 years of life saved, or $590-$1784 per year of life saved.