There are significant losses at each step of the post-exposure prophylaxis (PEP) ‘treatment cascade’, according to a systematic
review and meta-analysis of 97 studies presented to the 20th
International AIDS Conference (AIDS 2014) in Melbourne yesterday. The problems with uptake,
adherence and completion point to a need for a simplified approach, comment the
authors.
PEP is a 28-day course of two or more antiretroviral drugs,
taken by HIV-negative individuals who believe they may have been exposed to
HIV, for example after a needlestick injury in a healthcare facility, when a
condom has split, or following sexual assault.
Nathan Ford and colleagues from the World Health
Organization identified all studies of PEP that reported on completion rates
and pooled their data. Information about 21,462 individuals in 97 separate
studies was included.
The majority of data (68 studies) were from high-income
countries, with fewer reports from low- and middle-income countries. Most
studies concerned PEP following sexual or other non-occupational exposure, but
there were also data on occupational exposure and sexual assault. A quarter of
studies included data on children or adolescents.
Of individuals who were assessed by a healthcare provider
and judged to be eligible for PEP, 14% chose not to take it. Of all individuals
starting PEP (and not subsequently judged to be ineligible), only 56.6%
completed the 28-day course.
Completion was poor for all populations and for all types of
exposure. However, it was especially low among female sex workers (48.8%) and
victims of sexual assault (40.2%).
Of those who completed the course, 31.1% failed to attend
for a follow-up visit that would include HIV testing.
Whereas some programmes give individuals the drugs for the
full 28 days of treatment, others initially offer a partial prescription
(sometimes called a ‘starter pack’) and require individuals to return to the
healthcare facility for more. Starter packs were most commonly provided for
cases of non-occupational exposure or sexual assault. However, fewer people
given starter packs completed the course (53.2%) than people given the full
course (70.0%). Over a quarter of those given a starter pack failed to return
for the rest of the prescription.
Interventions to improve uptake and retention, and a
simplified approach, are needed, say the authors. They also say that the
problems with PEP give insight into the challenges for adherence to
pre-exposure prophylaxis (PrEP), which also involves HIV-negative people taking
antiretroviral drugs.