Uptake of and virological response to antiretroviral therapy among HIV‐infected former and current injecting drug users and persons in an opiate substitution treatment programme: the Swiss HIV Cohort Study

Abstract

ObjectivesThe aim of the study was to investigate the influence of continued injecting drug use, enrolment in an opiate substitution treatment programme (OSTP), or cessation of injecting drug use on the uptake and course of antiretroviral therapy (ART). DesignA prospective observational study of all participants in the Swiss HIV Cohort Study followed between 1997 and 2006 was carried out. MethodsWe distinguished four groups of former or current injecting drug users (IDUs): (i) abstinent former IDUs; (ii) persons in OSTPs without concomitant injecting drug use; (iii) persons in OSTPs with concomitant injecting drug use; (vi) current IDUs. These groups were compared with a group of patients who had never been IDUs. Factors related to ART uptake and virological endpoints were analysed using logistic generalized estimating equations. ResultsWe followed 8660 participants for 48 477 person-years; 29.7% were in the IDU HIV transmission group. The likelihood of being on ART at biannual visits was lower among individuals in OSTPs with concomitant injecting drug use [odds ratio (OR) 0.79; 95% confidence interval (CI) 0.71-0.89] and current IDUs (OR 0.80; 95% CI 0.67-0.96), compared with those who had never been IDUs (reference), abstinent former IDUs (OR 1.13; 95% CI 1.02-1.25) and individuals in OSTPs without injecting drug use (OR 1.18; 95% CI 1.06-1.31). The likelihood of suppressed viral replication on ART was similar among those who had never been IDUs, abstinent former IDUs and individuals in an OSTP without injecting drug use, and lower among those in OSTPs with concomitant drug use (OR 0.82; 95% CI 0.72-0.93) and current IDUs (OR 0.81; 0.65-1.00). Adherence to ART was decreased among persons with continued injecting drug use, and correlated with virological outcome. [4][5][6][7], the potential for interactions among medication, opiate substitution and illicit drugs [8], adverse effects [9], and limited access to [10,11], delayed use of [10,12,13], and decreased response to treatment [4,7]. As a consequence of such difficulties, physicians may be reluctant to offer ART to HIV-infected IDUs [14,15], resulting in less than optimal care and worse outcome [16,17].In HIV research, the term 'IDU' is commonly used to describe the HIV transmission category or patient characteristics. When investigating the course of HIV infection and the outcome of ART in these patients, however, it is an oversimplification to consider IDUs as a homogenous group. IDUs frequently change their drug injection behaviour, drug addiction treatment status or health care setting [18,19]. We aimed to investigate the influence of injecting drug use behaviour and enrolment in opiate substitution treatment programmes on the uptake of and virological response to ART among persons classified as belonging to the IDU HIV transmission group, and to study the association between injecting drug use behaviour and adherence to ART. We distinguished four distinct groups of former or current IDUs: (i) abstinent former IDUs who had completely stopped injecting d...

Participation, characteristics and retention rates of HIV‐positive immigrants in the Swiss HIV Cohort Study*

“…Older age may be a proxy for less mobility and more comorbidity. Although a large proportion of participants with IDU as the transmission risk in Switzerland have stopped injecting drugs [30], IDU remains an important and independent risk factor for LTFU [10,11,29]. People with a higher baseline CD4 cell count or who were treatment-naïve were more prone to LTFU, a finding in congruence with research from France [29].…”

Opioid substitution therapy in resource-poor settings

“…3 Opioid substitution therapy programmes are effective in substantially reducing illicit opiate use, HIV risk behaviours, death from overdose and criminal activity, and financial and other stresses on drug users and their families. [4][5][6] These programmes also improve adherence to antiretroviral therapy and the physical and mental health of injecting drug users. [4][5][6] Many injecting drug users who would otherwise have no contact with any health services are attracted by these programmes, which then act as gateways to other services including primary health care, HIV testing, antiretroviral therapy and services for tuberculosis, hepatitis C and sexually transmitted infections.…”

“…[4][5][6] These programmes also improve adherence to antiretroviral therapy and the physical and mental health of injecting drug users. [4][5][6] Many injecting drug users who would otherwise have no contact with any health services are attracted by these programmes, which then act as gateways to other services including primary health care, HIV testing, antiretroviral therapy and services for tuberculosis, hepatitis C and sexually transmitted infections. 7 Additionally, a critical ingredient of the HIV-prevention response is mobilization of affected communities, which is only possible for injecting drug users when they are not fully occupied with obtaining an ongoing supply of illicit drugs.…”

Patients on Opioid Substitution Treatment in the Republic of Macedonia: What Do Treatment Demand Data Tell Us?

“…Care of IDUs (intravenous drug users) requires interdisciplinary treatment of drug addiction and its psychosocial and somatic complications [10]. There are different treatment modalities available in different countries and studies have shown that treatment interventions can have great benefits.…”