The proportion of unattended elderly people out of the total number of older individuals in sub-Saharan Africa increased significantly from 23.5% at the earliest surveys (median year 1993) to 26.1% at the most recent surveys (median year 2004; P=0.04). Table 1 shows the demographic characteristics of the sample. Compared with older individuals who lived with prime age adults, unattended elderly people were less likely to be men, to live in urban environments, and to have completed primary school (P<0.001 for all). They were also less likely to have assets at home such as radios (P<0.001), suggesting that living alone is associated with lower socioeconomic status.
| Table 1 Characteristics of the elderly population |
Figure 1 shows the relation between the AIDS mortality rate (AIDS related deaths per 1000 people) and the proportion of elderly people living alone without any prime age adults. Each data point in the figure represents a country-year observation. The scatterplot and accompanying regression line (fit by ordinary least squares using population weighted samples) show a positive correlation between the AIDS mortality rate and the proportion of unattended elderly individuals. Figure 2 shows the association of the AIDS mortality rate with the proportion of missing generation households. This figure suggests an association between the severity of the HIV/AIDS epidemic and the proportion of older people serving as primary caretakers of young children. Further analyses presented in the web extra suggest that this relation is not attributable to the undue influence of outliers.
The results of tests for the strength of the association between the AIDS mortality rate and the living arrangements of elderly individuals are shown in table 2. We present the marginal effects obtained from the probit models and coefficient estimates obtained from the linear regressions (using population weights in all cases). The severity of the HIV/AIDS epidemic was significantly and positively associated with the proportion of older people living unattended. After adjusting for age, sex, place of residence (urban or rural), education, measures of household wealth (that is, whether individuals had electricity, flush toilets, plumbing, dirt floors, bikes, and radios), and country, a one point increase in the AIDS mortality rate was associated with a 1.53% increase in the proportion of older people living alone (95% CI 1.19% to 1.87%; P<0.001) and a 0.42% increase in the proportion of older people living in missing generation households (95% CI 0.31% to 0.58%; P<0.001). The unadjusted analysis yielded similar results to the adjusted analysis.
| Table 2 AIDS mortality rate and changes in support for elderly people in Africa* |
We observed a similar pattern between the HIV/AIDS epidemic and the number of prime age adults living with elderly individuals (table 2). An increase in the annual AIDS mortality rate of one extra death per 1000 people was associated with 0.13 fewer prime age adults per elderly individual in households with at least one prime age adult. After adjustment, the number of prime age adults per elderly household fell by 0.07 for each one point increase in AIDS mortality rate (95% CI −0.09 to −0.06 P<0.001).
Finally, we used our parametric estimates to assess the population impact of the HIV/AIDS epidemic on the living arrangements of elderly individuals in each of the countries examined. Table 3 shows estimates of the number of unattended elderly people linked to AIDS mortality in 2006. The calculations in table 3 assume that the same parametric relation between unattended elderly people and AIDS mortality within our study sample holds for each country in 2006. The results of the “leave one out” analysis presented in the web extra suggest that this assumption is reasonable because the parametric relation is stable across countries and time.
| Table 3 Number of unattended elderly people associated with AIDS mortality in 2006 by country* |
Our estimates suggest that in the 22 African countries included in our study, an additional 582

200-917

000 elderly people were living unattended because of deaths from AIDS in 2006 (using the 95% upper and lower confidence bounds for each country). Using similar methods, we estimated that the HIV/AIDS epidemic was responsible for an additional 141

000-323

100 older individuals living in missing generation households in the 22 study countries in 2006. Notably, only 70% of the population in sub-Saharan Africa lives in these countries, suggesting that the overall numbers for the entire continent are even larger.