By 2040, 46% of adults with diagnosed human immunodeficiency virus (HIV) in 24 US states are projected to be aged 65 years or older, double the proportion in 2025, according to a modeling study. The median age is expected to rise from 51 to 61 years, with substantial differences in aging patterns across states.

Researchers used the Johns Hopkins Epidemiologic and Economic Model, a dynamic, compartmental model of HIV transmission, to project changes in the population with diagnosed HIV in the modeled states, which together account for approximately 86% of people with diagnosed HIV nationwide. The model generated 1,000 simulations of demographic changes from 2025 through 2040, assuming that recent trends in HIV transmission and public health programming would continue. Outcomes included changes in median age, the number and proportion of people aged 55 years or older and 65 years or older, and differences by HIV acquisition risk group, race, and ethnicity.

Alongside the 10-year increase in median age, the proportion of people with diagnosed HIV aged 65 years or older was projected to rise from 23% to 46%. The number in this age group would increase from approximately 214,000 to 459,000. By comparison, the median age of the general adult population across the modeled states was expected to remain near 44 years.

The model also estimated an increase in the total population with diagnosed HIV, from 917,115 in 2025 to approximately 1 million in 2040. The proportion aged 55 years or older would rise from 45% to 55%.

Substantial geographic differences emerged. Larger, more urban states with higher baseline median ages were projected to experience greater aging. In California, the median age of people with diagnosed HIV was projected to increase from 53 years in 2025 to 67 years in 2040. New York would also reach a median age of 67 years, followed by Maryland at 65 years and Florida at 64 years.

Conversely, states with smaller, more rural HIV epidemics were projected to experience less aging or declines in median age. In Arkansas, the median age would decrease from 45 to 39 years, while in Oklahoma it would fall from 46 to 39 years. The researchers cautioned that projections for states with smaller HIV epidemics were less precise.

Among men who have sex with men and have diagnosed HIV, the median age was projected to increase from 48 to 57 years, compared with an increase from 54 to 61 years among other people with diagnosed HIV. Among Hispanic people with diagnosed HIV, the corresponding increase was from 48 to 61 years, compared with 48 to 54 years among non-Hispanic Black people and 56 to 65 years among people in the combined non-Black, non-Hispanic category.

In a secondary analysis, the ratio of new HIV diagnoses to diagnosed HIV prevalence showed the strongest correlation with projected changes in median age across states, with a Spearman correlation coefficient of −0.70. States with higher ratios generally experienced smaller increases in median age. The extent of aging was also associated with baseline median age, HIV prevalence, and the age distribution of newly diagnosed people.

The study had several limitations. Changes in transmission patterns or survival through 2040 could alter the findings. The model also assumed uniform transmission mixing within states and estimated individual ages from 5 broad age categories, introducing uncertainty not fully captured by the reported credible intervals.

Federal and state HIV programs may need to prepare for increasing demand for integrated HIV and primary care, management of cardiovascular and metabolic comorbidities, and services addressing cognitive, mental, and social health needs. However, the projected differences across states indicate that planning may need to reflect local demographic patterns rather than a uniform national approach.

"These projections can inform planning for managing and preventing age-related comorbidities to optimize the health of people aging with HIV," wrote lead study author Andrew Zalesak, MS, of the Johns Hopkins University School of Medicine, and colleagues.

The authors reported no conflicts of interest. The study was funded by the National Institutes of Health.

Source:JAMA Network Open