The life expectancy of patients receiving antiretroviral
therapy in the UK improved significantly between 1996 and 2008, research
published in the British Medical Journal
shows. Patients who initiated HIV therapy when their CD4 cell count was in the
region of 350 cells/mm3 had an average life expectancy of
approximately 75 years.
However, starting HIV therapy with a CD4 cell count below
200 cells/mm3 was associated with a poorer prognosis, highlighting
the importance of improved HIV testing and the prompt initiation of therapy.
“Life expectancy is strongly related to the CD4 count at
which individuals start treatment,” write the investigators from the UK
Collaborative HIV Cohort (UK CHIC). “This highlights the need to identify
people infected with HIV early in the course of their infection, before
substantial CD4 loss has occurred.”
Results also showed that, overall, the average
life-expectancy of patients with HIV was about 13 years lower than that for the
general UK population. However, all the average life expectancy figures reported by the researchers necessarily include patients who started treatment late. This group of patients are known to have a worse prognosis.
HIV is now considered a chronic, manageable condition, and
with the right treatment and care the prognosis of many patients is excellent. Although several studies have examined
mortality rates in the era of effective HIV therapy, few have examined how long
patients with HIV can now expect to live.
“Estimates of life expectancy are important to individuals
who want to plan their lives better, to service providers, and to policy
makers,” explain the investigators. They therefore used data collected between
1996 and 2008 to estimate the life expectancy of patients who started HIV
therapy when their CD4 cell count was below 350 cells/mm3, the
current threshold for starting antiretroviral treatment in the UK.
The life expectancy of patients with HIV was compared with
the life expectancy of the general UK population, and the investigators also
calculated the impact of late initiation of HIV therapy on prognosis.
A total of 17,661 individuals aged 20 and above were
included in the study. Most of the patients were men (75%), white (58%), and
their median age was 37 years. Overall, 42% of patients started HIV treatment
late – defined as a CD4 cell count below 200 cells/mm3.
Patients were followed for a median of 5 years, and during
91,203 person years of follow-up a total of 1248 (7%) of individuals died. The
overall mortality rate was 13.7 per 1000 person years. However, this fell from
28.8 per 1000 person years in 1996-99 to 9.5 per 1000 years between 2006-08. Improvements in HIV treatment in care
over the period largely account for this fall in the mortality rate.
The investigators calculated that a 20-year-old receiving
HIV therapy in 1996-99 would live on average a further 30 years. This life expectancy increased
to 46 years in the period 2006-08.
Life expectancy for a 35-year-old was an additional 20 years
of life in 1996-99, and 31 years in the period 2006-08.
However, prognosis differed by gender, and was significantly
better for women than men. Overall, life expectancy for a 20-year-old woman was
an additional 50 years compared to 40 years for men.
HIV-positive patients had a significantly shorter life
expectancy than individuals in the general population. A HIV-negative
20-year-old woman would be expected to survive until she was 82 years old and
an HIV-negative man until he was 78.
“Compared with the same sex in the general UK population,
for patients undergoing treatment for HIV infection, life expectancy at age 20
was 18.3 years less for men and 11.4 years less for women,” write the
They note “the prevalence of smoking, drug misuse, and
alcoholism are all higher among people with HIV, which leads to increased
deaths from cardiovascular disease, cancer, liver disease, suicide, overdose
But further analysis showed that starting HIV treatment
promptly significantly improved prognosis – which approached normal levels for
patients who initiated therapy at a level indicated by current guidelines.
Patients who started therapy with a CD4 cell count between
200 and 350 cells/mm3 had an average life expectancy of 75 years,
but this fell to 61 years for individuals who initiated therapy when their CD4
cell count was between 199 and 100 cells/mm3 and to 58 years for
those who started treatment with a CD4 cell count below 100 cells/mm3.
should start antiretroviral therapy once their CD4 cell count has fallen below
350 cells/mm3,” emphasise the investigators.
“Life expectancy among people with HIV has considerably
improved in the UK between 1996 and 2008, and we should expect further
improvements for patients starting antiretroviral therapy now with improved
drugs and new guidelines recommending earlier treatment,” conclude the authors.
“The clear impact of low CD4 cell count on life expectancy implies that it is
particularly important to diagnose HIV infection at an early stage.”