Evaluation of an Inner City HIV Pre-Exposure Prophylaxis Service Tailored to the Needs of People Who Inject Drugs

Ceilidh Grimshaw; Lynsey Boyd; Matt Smith; Claudia S. Estcourt; Rebecca Metcalfe


HIV Medicine. 2021;22(10):965-970. 

In This Article

Abstract and Introduction


Objectives: HIV prevention strategies including pre-exposure prophylaxis (PrEP) must reach all in need to achieve elimination of transmission by 2030. Mainstream provision may inadvertently exclude key populations. Incidence of HIV in people who inject drugs (PWID) in Glasgow, Scotland's largest city, is increasing, partly due to sexual transmission. Scotland provides publicly funded oral PrEP for individuals at sexual risk of HIV through sexual health services; however, uptake by PWID has been negligible. We developed a tailored outreach PrEP service based in the local homeless health centre. We used active case finding, flexibility of assessment location, supervised community daily dispensing and active follow-up to optimise uptake and adherence. We describe a two-year service evaluation.

Methods: We reviewed the case records of all PWID identified by the outreach team as being at higher risk of sexual acquisition for whom PrEP was considered between November 2018 and November 2020. Evaluation focused on PrEP uptake, adherence and monitoring. We conducted a descriptive statistical analysis.

Results: Of 41 PWID assessed as eligible, 32 (78.0%) commenced PrEP. The proportion of PrEP-covered days was 3320/3400 days (97.6%); 31/32 (96.9%) had regular HIV serology monitoring. The service was feasible to run, but it relied on outreach provision and liaison with other services.

Discussion: Tailored PrEP services can reach PWID effectively. Uptake and adherence were high but the model was resource-intensive. Appropriately tailored PrEP delivery may be required to meet the needs of this and other key populations who experience barriers to accessing mainstream services.


Globally, one in 10 HIV infections occur in people who inject drugs (PWID).[1] Established combination prevention strategies have focused on needle exchange, opiate substitution therapy (OST) and drug rehabilitation,[2] in addition to HIV testing and early antiretroviral therapy (ART). However, once an HIV outbreak is established within an injecting population, sexual transmission also becomes important. Oral tenofovir disoproxil/emtricitabine as pre-exposure prophylaxis (PrEP) is highly effective at reducing sexual transmission of HIV.[3,4] It was associated with 48.9% reduction in HIV acquisition in the only study of PrEP effectiveness in PWID.[5]

Since 2015, there has been an HIV outbreak among PWID in Scotland's largest city, Glasgow (population 1 million). It is associated with cocaine injecting, homelessness and incarceration[6] despite high coverage of needle exchange and OST. The link between cocaine use and sexual behaviours, as well as the higher than expected HIV incidence among females supports sexual transmission.[6] Indeed, sexual contact was reported as a potential transmission route by almost 50% of individuals at diagnosis.[7]

Scotland implemented a national state-funded programme delivering PrEP and associated monitoring free of charge through sexual health clinics in 2017. Provision is for individuals at risk of sexual (but not injecting-associated) acquisition. A 20% reduction in new HIV diagnoses in gay and bisexual men followed implementation,[8] but there has been limited impact on other groups.[9,10] This is perhaps unsurprising among PWID, who may find it difficult to engage with mainstream health services.[11] PWID experience barriers to HIV testing and prevention,[12] including fear of criminalization or stigma, lack of transport, and difficulties prioritizing healthcare.

In 2018, HIV prevalence in PWID in Glasgow inner city reached almost 11%.[6] As part of the outbreak control response, we commenced a bespoke PrEP service, providing daily oral tenofovir disoproxil/emtricitabine. We carried out a service evaluation with the objective of assessing uptake and adherence of PrEP among PWID identified as being at higher risk of sexual transmission of HIV. The service is described in the following to offer insights into the interventions used to achieve these outcomes.

Developing a Tailored PrEP Service Model for PWID

A qualitative study exploring perceptions of PrEP among PWID at the epicentre of the outbreak[13] highlighted that, in addition to service barriers, PWID had poor health literacy and tended to underestimate HIV risk. Participants welcomed PrEP but had a strong preference for provision in familiar settings where they were engaging with other services and had trusting relationships with providers.[13]

Building on experience of a successful model of collaborative HIV treatment delivery in PWID in Glasgow,[7] a small team developed a tailored PrEP service. Novel strategies were needed to facilitate identification of PrEP candidates, initiation of PrEP and adherence. Key components are shown in Figure 1.

Figure 1.

Key components of the pre-exposure prophylaxis (PrEP) model

Identifying PWID With Sexual Risk of HIV Acquisition and Initiating PrEP

Active case finding rather than reliance on individuals' self-identification as PrEP candidates was used. Sexual health (SH) nurses embedded within the homeless health clinic offered blood-borne virus information and testing, contraception and sexual healthcare. Service users were informed about PrEP during these consultations. The PrEP assessments and venepuncture were carried out for at-risk individuals. Sexual health staff also raised awareness among the allied services, encouraging staff to discuss HIV risk and signpost patients to the team.

At baseline, consent was sought to liaise with allied services, including patients' OST prescribers and community pharmacies. The physician reviewed the cases and results remotely, overseeing prescribing, monitoring and requesting additional investigations as appropriate.

Facilitation of Adherence to PrEP, Retention in Care and Resources

Almost all individuals identified were receiving OST supervised at community pharmacies. PrEP was dispensed at community pharmacies alongside OST as directly observed therapy (DOT). Community pharmacists informed HIV specialist pharmacists of lapses in adherence. Any lapses triggered the SH nurses to contact the individual via phone (or liaise with other key services if necessary) to ascertain the reason and facilitate recommencement. Recall for regular monitoring was done in the same way. Individuals were offered flexible timings and locations (most often homeless health or addiction services) for subsequent appointments, enabling PrEP to be integrated with other needs. Some were ad hoc whilst individuals attended health/addiction services for other purposes. Communication with prison services was also important as incarceration caused adherence breaks.

This model relied upon highly experienced SH outreach nurses (37 h/week), HIV physician (2 h/week), HIV pharmacist (1 h/week), HIV pharmacy technician (2 h/week), and a clinical room at the homeless health centre.

For comparison, in mainstream SH services in Glasgow, PrEP is accessed by appointment. Quarterly reviews consist of a 15-min telephone assessment with a SH nurse/junior doctor followed by a clinic visit for monitoring tests and PrEP collection. Adherence is self-reported and disengagement from care is assumed to indicate cessation of PrEP with no active follow-up. HIV physician support is available, but it is not required for the majority of clients.