Substantial improvement in life expectancy of older HIV-positive patients in modern treatment era, report Danes

The prognosis of older HIV-positive patients has improved substantially during the era of combination antiretroviral therapy (cART), according to Danish research published in the online edition of the Journal of Acquired Immune Deficiency Syndromes. Investigators analysed mortality rates among HIV-positive patients aged 50 years and over between 1996 and 2014. The median survival time improved from 12 years between 1996-99 (total life expectancy of 62 years) to 23 years between 2006-14 (total life expectancy of 73 years). But, the projected life expectancy for HIV-positive patients was significantly poorer for older HIV-positive patients compared to age- and gender-matched individuals in the general Danish population, even when analysis was restricted to those without AIDS or co-morbidities who were doing well on cART.

“Mortality among HIV-infected individuals > 50 years decreased markedly during the period 1996-2014,” comment the authors, “but estimated median survival time from age 50 years still remained substantially lower than in the background population.”

Thanks to cART the life expectancy of many patients with HIV in richer countries is now approaching normal, and between a third and a half of HIV-positive individuals in these countries are now aged 50 years and above. Diseases of ageing are an increasingly important cause of serious illness and death among patients with HIV, and there is evidence to suggest that these diseases develop at a younger age in the context of HIV infection.

Danish doctors wanted to get a clearer understanding of long-term mortality risk in older HIV-positive patients. They therefore designed a population-based cohort study involving approximately 2400 patients aged 50 and above who received care between 1996-2014. Each patient was matched with an individual in the general Danish population of the same age and sex.

Survival was monitored in three periods: 1996-99; 2000-2005; 2006-14. The investigators calculated all-cause mortality rates (MR) per 1000 person-years; excess mortality rates (EMR) per 1000 person-years and mortality rate ratios (MRR) per 5-year age internals for both the HIV-positive patients and the controls. A sub-analysis also compared survival estimates between patients who received care between 2006-14 who were doing well on HIV treatment (viral load below 500 copies/ml, CD4 count above 350 cells/mm³) and without AIDS or co-morbidities to survival estimates for co-morbidity-free individuals in the general population.

Over a fifth (22%) of HIV-positive patients died during follow-up compared to 10% of controls.

Median survival time for patients with HIV increased during the study period, from 12 years in 1996-99, to 18 years in 2000-05 and 23 years in 2006-14. Median survival for the controls was approximately 30 years throughout the 18 years of the study.

“We found that during the study period the median estimated survival time for an HIV-infected individual from age 50 increased by more than 10 years,” comment the researchers.

For patients with HIV, the MRR decreased with increasing age (3.8 for 50-55 years to 1.6 for 75-80 years). The excess mortality rate increased with age from 16.3 for 50-55 yeas to 48.8 for 76-80 years. The highest excess mortality rate was recorded between 1996-99 and was lower in all age strata in subsequent time periods.

HIV-positive patients in care between 1996-99 had an increased mortality risk compared to patients observed between 2006-2014 (MRR 1.5 for 50-55 age group, 9.5 for 75-80 age group).

A total of 517 patients without AIDS or co-morbidities and doing well on cART were matched with 3,192 co-morbidity-free controls during the period 2006-14.

HIV-positive patients had an estimated life expectancy of 76 years compared to 84 years for the controls.

“Even among well-treated HIV-infected individuals > 50 years without AIDS-defining events or co-morbidity the estimated median survival time was still markedly lower than in the background population,” write the authors.

They conclude that survival among older HIV-positive patients has increased markedly in recent years. Nevertheless, they believe their results “indicate that further incentives to reduce mortality among HIV-infected individuals > 50 years are needed.”