Life expectancy of HIV-positive people from age 50 rose by more than 10 years from 1996-1999 to 2006-2014, according to results of a nationwide study in Denmark. But even in a subgroup of 50-and-older HIV patients without AIDS or comorbidities, mortality significantly exceeded the rate in a similarly healthy HIV-negative comparison group.
The proportion of HIV-positive people 50 or older is rising across the world. Older people with HIV face greater threats to their health than younger people because of a higher risk of late HIV diagnosis, slower CD4+-cell gains with antiretroviral therapy (ART) and age-related comorbidities. Danish researchers conducted this nationwide study to compare all-cause mortality in people 50 and older with and without HIV infection.
The analysis involved adults in the Danish HIV Cohort Study, which includes everyone diagnosed with HIV in Denmark and treated for free at one of eight HIV centers. All HIV-positive study participants had reached age 50 between January 1996 and May 2014 and survived at least one year after HIV diagnosis. For each HIV-positive person, the researchers selected six general-population controls matched by age and sex.
From the HIV group, the investigators identified a cohort of "well-treated" individuals who had taken ART for at least one year, had a viral load below 500 copies/mL, had a CD4+ count ≥ 350 cells/mm3 and had no AIDS illnesses or non-HIV comorbidities one year after starting ART. Six age- and gender-matched general-population controls for this "well-treated" HIV group had no comorbidity at study inclusion. For both the HIV group and controls, comorbidity meant a Charlson comorbidity index ≥ 1, HCV infection, alcohol or drug abuse, or injection drug use.
The researchers used Kaplan-Meier analysis to calculate survival in three periods: 1996-1999, 2000-2005 and 2006-2014. They used Cox proportional hazards analysis to estimate mortality rate ratios for HIV-positive participants compared with general-population controls.
The main analysis involved 2440 HIV-positive people, 530 (21.7%) of whom died, and 14,588 population controls, 1388 (9.5%) of whom died. Most HIV-positive people and general-population controls were men (84%) and white (89%). A larger proportion of HIV-positive people than controls had a Charlson comorbidity index ≥ 1 (14% versus 6%). At HIV diagnosis, median age stood at 43 years and median CD4+ count at 252 cells/mm3.
Estimated median survival in the HIV group rose from 11.8 years in 1996-1999 to 17.8 years in 2000-2005 and to 22.5 years in 2006-2014. Median survival in general population controls was 30.2 years across all three periods. Mortality rate ratio comparing HIV-positive people with controls was highest among 50- to 55-year-olds (3.8) and declined in each older age group. But in the oldest age group, 75- to 80-year-olds, people with HIV still had a significantly higher death rate than population controls (mortality rate ratio 1.6, 95% confidence interval [CI] 1.0 to 2.6). Mortality did not differ substantially between HIV-positive people diagnosed before or after age 50.
The "well-treated" subset included 517 people with HIV and 3192 age- and gender-matched general-population controls. Estimated median survival from age 50 was 25.6 years in the HIV group (to age 75.6) versus 34.2 years in controls (to age 84.2). Those numbers meant people with HIV but without AIDS or comorbidities had a 70% higher death rate than general-population controls without comorbidities (mortality rate ratio 1.7, 95% CI 1.2 to 2.3).
The researchers concluded that "survival after age 50 has improved markedly in the HIV-population within the [combination ART] era, but is still substantially lower than in the background population," even in "well-treated" HIV-positive people without AIDS or comorbidities.