Voucher incentives improve engagement with HIV care among people who inject drugs

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Providing vouchers exchangeable for food or household goods boosts rates of linkage and retention in HIV care among people living with HIV who inject drugs, according to research published in the online edition of Clinical Infectious Diseases. However, voucher incentives were not associated with increased rates of virological suppression, a finding the investigators think should be explored in future research. The study was conducted in Chennai, India.

Globally, people who inject drugs are one of the groups most affected by HIV. Typically, people who inject drugs have poorer outcomes than other people living with HIV. In many settings, rates of linkage and retention in HIV care are especially low among people who inject drugs.

Approximately a quarter of people who inject drugs in Chennai, India, are living with HIV. This group has a high mortality rate.


control group

A group of participants in a trial who receive standard treatment, or no treatment at all, rather than the experimental treatment which is being tested. Also known as a control arm.

linkage to care

Refers to an individual’s entry into specialist HIV care after being diagnosed with HIV. 

retention in care

A patient’s regular and ongoing engagement with medical care at a health care facility. 

continuum of care

A model that outlines the steps of medical care that people living with HIV go through from initial diagnosis to achieving viral suppression, and shows the proportion of individuals living with HIV who are engaged at each stage. 

pilot study

Small-scale, preliminary study, conducted to evaluate feasibility, time, cost, adverse events, and improve upon the design of a future full-scale research project.


An international team of investigators wanted to see if rates of linkage and retention in HIV care would be increased by providing people who inject drugs with voucher incentives to attend antiretroviral treatment (ART) clinics.

They therefore designed a small pilot study involving 120 people living with HIV who use drugs. Recruitment took place between 2009 and 2010 and the study lasted twelve months.

All the study participants were eligible to initiate antiretroviral therapy according to the national guidelines in India.

Participants were randomised into an incentive or a control arm. The incentive consisted of vouchers worth between INR200 and INR400 (US$4-8) for presenting at a government ART clinic, attending monthly follow-up appointments, starting ART and achieving an undetectable viral load. The vouchers could be exchanged for food or household goods. People in the control arm of the study were not offered incentives for achieving treatment goals. However, they had an opportunity to win vouchers in a “prize bowl”.

The median age was 39 years and 91% of participants were male. Median baseline CD4 count was between 248 and 268 cells/mm3, and median baseline viral load was between 55,000 copies/ml and 125,000 copies/ml. Fifty-three people had hepatitis C virus co-infection.

A total of 19 study participants died during follow-up, a mortality rate of 17.9 per 100 person-years. Seven deaths were related to tuberculosis and three were classified as non-AIDS related.

Results of the study favoured the provision of vouchers.

People in the incentive arm were significantly more likely to link with HIV care than people in the control arm (n = 49 vs 33, p = 0.002).

Analysis of the participants attending an ART centre showed that 45% of those in the incentive arm compared to 27% of those in the control arm started HIV treatment (p = 004).

People eligible for incentive vouchers started antiretrovirals significantly sooner than people in the control group (p = 0.015).

After taking into account potential confounders, the investigators found that voucher incentives were associated with an almost threefold increase in the chances of starting HIV treatment (HR = 2.93; 95% CI, 1.39-6.20).

People in the incentive group also had more monthly follow-up visits compared to people in the control group (median 8 vs 4, p = 0.005).

However, voucher incentives were not associated with improved outcomes. Approximately a third of people in both study arms had an undetectable viral load at the end of the study and CD4 count increases at the twelve-month follow-up point were also comparable.

“Modest non-monetary voucher incentives were associated with higher rates of linkage to care, ART initiation and retention to care among drug users,” comment the authors. “These findings illustrate the potential for voucher incentives to improve multiple steps in the HIV care continuum.”

They believe further research is needed “to characterize the steps in the care continuum where incentives will be most beneficial and to develop integrated multi-faceted interventions to engage and retain marginalized populations of HIV-infected persons in care.”


Solomon SS et al. Voucher incentives improve linkage to and retention in care among HIV-infected drugs users in Chennai, India. Clin Infect Dis, online edition, 2014.

This news report is also available in Russian.