Incarceration is associated with poor adherence to HIV
therapy among injecting drug users, an international team of researchers report
in the May 1st edition of the Journal
of Infectious Diseases.
Just one instance of imprisonment increased the risk of
sub-optimal adherence to antiretroviral treatment, and the more often a patient
was incarcerated then the greater their risk of poor adherence.
“We observed a dose-dependent association between the
cumulative burden of incarceration and ART [antiretroviral therapy] nonadherence,”
comment the investigators, who believe their study “clearly indicates that
increasing number of cycles of imprisonment, release and reincarceration is
associated with poorer ART adherence in this population of IDUs [injecting drug
Thanks to modern antiretroviral therapy, many HIV-positive
individuals now have a near-normal prognosis. High levels of adherence are
needed to achieve the best outcomes.
Good results have been seen in HIV-positive injecting drug
users treated with antiretrovirals. However, some drug users have difficulty
achieving the high levels of adherence necessary for optimal viral suppression.
Incarceration is common among drug users, and it has been
estimated that approximately 10% of HIV-positive individuals are imprisoned
each year in the US. Significantly for HIV treatment outcomes, some research
had suggested that incarceration is associated with an increased risk of
interrupting antiretroviral therapy.
Therefore, a team of Canadian and British investigators
sought to estimate the frequency of imprisonment among HIV-positive drug users
and the association between incarceration and sub-optimal adherence to
The study was conducted in Vancouver, British Columbia, and
its population included 490 HIV-positive injecting drug users who were enrolled
in the AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS).
Recruitment and follow-up took place between 1996 and 2008.
All the patients were taking antiretroviral therapy, and
every six months they were interviewed about their experiences of incarceration.
Adherence was assessed using pharmacy refill records, and
was defined as sub-optimal if below 95%. Incarceration was defined as spending
at least one night in police custody or a prison of some kind.
The median duration of follow-up was a little under 29
months and the investigators had a total of 2220 person-years of follow-up
available for analysis.
Over half (55%) of the patients were imprisoned at least once,
and the overall incarceration rate was 52.5 per 100 person years. The median
number of incarcerations per patient was three, and there were a total of 1156
During the entire period of the study, the overall adherence
rate was 61%, well below the target 95%. Of the 3731 six-month follow-up
periods included in the investigators’ analysis, 36% were characterised by
sub-optimal levels of adherence.
There was a robust association between experiencing
incarceration and poor adherence to HIV therapy.
Compared to individuals with no history of incarceration,
those imprisoned on one or two occasions were almost twice as likely to be
non-adherent during subsequent follow-up (odds ratio [OR], 1.91; 95% CI,
The risk of sub-optimal adherence increased to 2.85 (95% CI,
1.87-4.33) for patients incarcerated who had three to five experiences of
incarceration, and an even higher risk of poor adherence was observed for
individuals with five or more episodes of imprisonment (OR = 3.59; 95% CI,
These results remained substantially unaltered when the
investigators controlled for sex, cocaine use, engagement in methadone
treatment programmes, duration of HIV therapy and viral load.
Modern combinations of antiretrovirals can achieve good
results with adherence rates of approximately 85%. However, the investigators
found that increased frequency of incarceration was still associated with a
greater risk of treatment non-compliance using this definition of adherence.
“Because of the tight link between nonadherence and HIV
disease progression, our findings have direct relevance to public health
efforts to reduce AIDS-related morbidity and mortality and continued viral
transmission,” comment the authors.
They conclude, “given the importance of correctional
facilities in shaping the health of vulnerable HIV-positive individuals, our findings
should spur efforts to reform the delivery of in-prison HIV care and ease
transitions to noncorrectional environments.”