Best practice portal:
Harm reduction interventions for opioid injectors

This page refers to the current evidence on the effectiveness of the available harm reduction options for opioid injectors. Information on the methodology used and the definition of terms can be found on the methodology page.

Date of last update: 11.05.2012.     Next update: March 2013.

Harm reduction interventions for opioid injectors

What's new: Updated information on the effectiveness of OST and NSP on HIV and HCV related outcomes as well as on Naloxone to prevent overdose mortality.

Beneficial

Opioid substitution treatment (OST) to reduce HIV and risk behaviour

Opioid substitution treatment (OST) was found to be effective in systematic reviews (Mattick et al., 2009; Gowing et al., 2008, WHO, 2009) in:

• reducing HIV seroconversion, especially among those in continuous treatment (2 observational studies (N= 876) (RR 0.36, 95 % CI 0.19 to 0.66);
• reducing the risk of HIV infection by approximately 50 % (RR 0.45, 95 % CI 0.35 to 0.59)
• reducing the frequency of injection, the sharing of injecting equipment and injecting risk behaviour scores:
  • injecting behaviour: prevalence of injecting :
    • one observational study (N=255) (RR 0.87, 95 % CI 0.80 to 0.95);
    • one RCT (N=253) (RR 0.45, 95 % CI 0.35 to 0.59)
  • Injecting behaviour: proportion of patients sharing injecting equipment:
    • three observational studies (N=1321) (RR 0.54, 95 % CI 0.37 to 0.79)
• reducing the risk of unsafe sex:
  • commercial sex:
    • one observational study (follow up to 18 months) (N= 257) (RR 0.62, 95 % CI 0.45 to 0.86);
    • two observational studies (follow up 3-6 months) (N= 867) (RR 0.94, 95 % CI 0.87 to 1.02)

Opioid substitution treatment (OST) with methadone maintenance to reduce mortality

Opioid substitution treatment (OST) with methadone maintenance was found to be effective in systematic review (Mattick et al., 2009, Bargagli A.M. et al., 2007) in:

• reducing the risk of death:
  • mortality (any cause): three RCTs (N= 435) (RR 0.493, 95 % CI, 0.06 to 4.23) (¹)
  • mortality (any cause): five observational studies (N= 69970) (RR 0.3795, 95 % CI 0.29 to 0.48)
• reducing risk of overdose death for those retained in treatment compared to those waiting for treatment, those who have left treatment or those that are in detoxification treatment:
  • five observational studies (N=69 970) (RR 0.17, 95 % CI 0.05 to 0.63)

(¹): the measure from the RCT is not statistically significant, nevertheless the evidence when considered together with the results of the observational studies, is significant.

Likely to be beneficial

Combination of opioid substitution treatment (OST) and needle and syringe programmes (NSP) to reduce HIV or HCV incidence

The combination of OST and NSP has been found to be effective in a meta-analysis of observational studies (Turner et al., 2011) (5 studies, N= 919) in:

• reducing the odds of new HCV infection by nearly 80% (AOR 0.21, 95 % CI 0.08 to 0.52);
• reducing in self-reported needle sharing by 48% (AOR 0.52, 95 % CI 0.32 to 0.83);
• reducing mean injecting frequency by 20.8 injections per month (95 % CI -27.3 to -14.4).

Continuity of treatment from prison to community to reduce mortality

One RCT (Dolan et al., 2005, cited in EMCDDA, 2010) suggests that retention in MMT in prison settings is associated with:

• reduced mortality from all causes (OR 0.54, 95 % CI 0.20 to 1.43)
• reduced mortality for overdose

Drug consumption rooms (DCRs) to reduce injecting risk behaviour

Based on one systematic review and one meta-analysis of four cohort studies (Kerr et al., 2007, Hedrich, 2004, cited in EMCDDA, 2010) it was concluded that there is tentative evidence that DCR use is associated with:

• reduced injecting risk behaviour and improvements in injecting practices and hygiene, especially for injections that occur on DCR premises, and among those who are regular DCR users.

Pharmacy access in addition to dedicated needle and syringe programmes (NSPs) to reduce injecting risk behaviour

Based on one narrative (Tilson et al., 2007, cited in EMCDDA, 2010) and one systematic review (Wodak, 2004, cited in EMCDDA, 2010) without meta-analysis, there is tentative evidence to support the effectiveness of pharmacy access to needles/syringes — in addition to dedicated NSPs — in:

• reducing self-reported injecting risk behaviour among IDUs.

Needle and syringe programmes (NSP) to reduce HIV and injecting risk behaviour

Two narrative reviews (Tilson et al., 2007 and Gibson et al., 2001, cited in EMCDDA, 2010) and one systematic review (Wodak, 2004, cited in EMCDDA, 2010) of more than 100 studies, without meta-analysis, concluded that there is tentative evidence to support the effectiveness of NSPs in:

• reducing HIV incidence/prevalence among IDUs
• reducing self-reported injecting risk behaviour among IDUs.

Opioid substitution treatment (OST) to improve anti-retro-viral treatment in HIV positive opioid users

Opioid substitution treatment was found sufficiently supported by evidence in a synthesis of 4 narrative reviews (Malta et al.,2008; WHO, 2007b, Tilson et al., 2007, Lucas et al., 2006, cited in EMCDDA - ECDC 2011) in:

• improving the effectiveness of anti-retro-viral treatment in HIV positive opioid users.

Opioid substitution treatment (OST) to reduce HCV

A systematic review (Wright and Tompkins, 2006, cited in EMCDDA, 2010) without meta-analysis of 18 observational studies (N= 18332) conducted between 1993 and 2002 in 10 different countries over three continents found very limited evidence that OST can achieve:

• a reduction in the risk of HCV seroconversion among those in continuous treatment.

Opioid substitution treatment (OST) to reduce injecting risk behaviour in prison

Based on one narrative review (Stallwitz and Stover, 2007, cited in EMCDDA, 2010) that did not pool results from 4 observational studies and one RCT there is tentative evidence to support the effectiveness of prison-based OST in:

reducing injecting risk behaviour among IDUs by decreasing frequency of injection of heroin and other opiate use.

Trade-off between benefits and harms

No interventions met these criteria.

Unknown effectiveness

Drug consumption rooms to reduce HIV, HCV and mortality

Based on one systematic review and one meta-analysis of four cohort studies (Kerr et al. 2007, Hedrich, 2004, cited in EMCDDA, 2010) it was concluded that there is not enough evidence to support or discount the effect of DCRs on:

• HIV or HCV prevalence/incidence
• reduction of overdose deaths at the community level.

Pharmacy access to NSPs and vending machines to reduce HIV, HCV and injecting risk behaviour

One narrative review (Wodak, 2004, cited in EMCDDA, 2010) concluded that there is no evidence of the effects of pharmacy access to needles/syringes or vending machines on:

• reducing HIV transmission among IDUs.
• reducing HIV prevalence among IDUs.
• HCV prevalence/incidence among IDUs.
• reducing injecting risk behaviour among IDUs.

Naloxone training and prescription to prevent opioid overdose mortality

Naloxone training and prescription was analyzed in a narrative review including 6 articles on Naloxone distribution programs (Baca, 2005). Although all the studies proved a potential for reducing mortality, they often conclude that more research is needed.

Needle and syringe programmes to reduce HIV, HCV and injecting risk behaviour in prison

Two narrative reviews (Dolan et al., 2003; Stöver, 2003, cited in EMCDDA, 2010) enclosed in the EMCDDA HR monograph, concluded that there is insufficient evidence to either support or discount the effectiveness of prison NSPs in:

• reducing HIV transmission among IDUs.
• reducing HCV transmission among IDUs.
• reducing injecting risk behaviour among IDUs

Opioid substitution treatment (OST) to increase compliance to HCV treatment

Opioid Substitution Treatment (OST) to increase compliance to HCV treatment was considered not possible to assess due to the lack of ad-hoc studies in a synthesis based on a narrative review (Hellard et al., 2009, cited in EMCDDA - ECDC 2011) including 30 observational studies with a total number of patients superior to 4,000.

Opioid substitution treatment (OST) to increase HCV treatment virological response

Opioid Substitution Treatment (OST) association to HCV treatment virological response was considered still unknown in a synthesis based on a narrative review (Hellard et al., 2009, cited in EMCDDA - ECDC 2011) including 30 observational studies with a total number of patients superior to 4,000.

Opioid substitution treatment (OST) to reduce HIV and HCV in prison

One systematic review (Gowing et al., 2008, cited in EMCDDA, 2010) without meta-anlysis, did not find sufficient evidence to draw conclusions about the effect of OST on:

• HIV seroconversion in prison settings.

Data from one study in a jurisdiction with low HIV prevalence found no difference in:

• HIV incidence between those receiving methadone maintenance treatment (MMT) and controls 1 RCT (N=382) (RR 1.09, 95 % CI 0.30 to 4.01) (Dolan et al., 2003).

One narrative review (Stallwitz et al., 2007, cited in EMCDDA, 2010) found no evidence to either support or discount the effectiveness of OST with respect to:

• HCV transmission in prison settings.

Outreach and education to reduce injecting risk behaviour

Two narrative reviews (Coyle et al., 1998; Needle et al., 2005) comprising respectively 36 and 40 observational studies but not without performing meta-analysis, concluded that outreach and education intervention are effective in:

• reducing injecting risks behaviour (self-reported injection drug use, injection frequency, reuse of needles and syringes, reuse of other equipment such as cookers, cotton, and rinse water)

Primary needle exchange programmes to reduce HCV

Four narrative reviews (Gibson et al., 2001; Tilson et al., 2007; Wodak, 2004; Wright et al., 2006, cited in EMCDDA, 2010) concluded that there is insufficient evidence to either support or discount the effectiveness of NSPs in:

• reducing HCV transmission among IDUs.

Evidence of ineffectiveness

No interventions met these criteria.

References and definitions

References

• Baca, C. T. and Grant, K. J. (2005), ‘Take-home naloxone to reduce heroin death’, Addiction 100 (12), pp. 1823–31.
• Bargagli A., Davoli M., Minozzi S., Vecchi S., Perucci C. (2007). A Systematic Review of Observational Studies on Treatment of Opioid Dependence. Geneva, Switzerland, background document prepared for 3rd meeting of Technical Development Group (TDG) for the WHO Guidelines for Psychosocially Assisted Pharmacotherapy of Opiod Dependence, 17-21 September.
• Coyle, S. L., Needle, R. H. and Normand, J. (1998), ‘Outreach based HIV prevention for injecting drug users: a review of published outcome data’, in Needle, R. H., Coyle, S. and Cesari, H. (eds), HIV prevention with drugusing populations: current status and future prospects, Public Health Reports, 113 (Supplement 1), pp. 19–30.
• Dolan, K. A., Shearer, J., MacDonald, M., et al. (2003), ‘A randomised controlled trial of methadone maintenance treatment versus wait list control in an Australian prison system’, Drug and Alcohol Dependence 72 (1), pp. 59–65.
• Dolan, K. A., Shearer, J., White, B., et al. (2005), ‘Four-year follow-up of imprisoned male heroin users and methadone treatment: mortality, re-incarceration and hepatitis C infection’, Addiction 100 (6), pp. 820–8.
• EMCDDA (2010), Harm reduction: evidence and impacts, EMCDDA Monograph, Rhodes, T. and Hedrich, D. (editors), Publications Office of the European Union, Luxembourg.
• EMCDDA (2011), ECDC and EMCDDA guidance. Prevention and control of infectious diseases among people who inject drugs, Publications Office of the European Union, Luxembourg.
• Gibson, D. R., Flynn, N. M. and Perales, D. (2001), ‘Effectiveness of syringe exchange programs in reducing HIV risk behavior and HIV seroconversion among injecting drug users’, AIDS 15 (11), pp. 1329–41.
• Gowing L, Farrell M, Bornemann R, Sullivan L E, Ali R(2008). Substitution treatment of injecting opioid users for prevention of HIV infection. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD004145.
• Hedrich, D. (2004), European Monitoring Centre for Drugs and Drug Addiction, Lisbon.
• Hellard, M., Sacks-Davis, R., Gold, J. (2009), 'Hepatitis C Treatment for Injection Drug Users: A Review of the Available Evidence', Clinical Infectious Diseases, Volume 49, Issue 4, Pp. 561-573.
• Kerr, T., Kimber, J., De Beck, K. and Wood, E. (2007), ‘The role of safer injection facilities in the response to HIV/AIDS among injection drug users’, Current HIV Reports 4, pp. 158–64.
• Mattick R.P., Breen C., Kimber J., Davoli M., (2009). Methadone maintenance therapy versus no opioid replacement therapy for opioid dependence, Cochrane Database of Systematic Reviews, Issue 3. Art. No.: CD002209.
• Needle, R. H., Burrows, D., Friedman, S. R., et al. (2005), ‘Effectiveness of community-based outreach in preventing HIV/AIDS among injecting drug users’, International Journal of Drug Policy 16 (Supplement 1), pp. 45–57. (Also at: Evidence for Action on HIV prevention among Injecting Drug Users, World Health Organization, Department of HIV/AIDS, Geneva, 2004.)
• Stallwitz, A. and Stöver, H. (2007), ‘The impact of substitution treatment in prisons: a literature review’, International Journal Drug Policy 18 (6), pp. 464–74.
• Stöver, H. and Nelles, J. (2003), ‘Ten years of experience with needle and syringe exchange programmes in European prisons’, International Journal of Drug Policy 14 (5–6), pp. 437–44.
• Tilson, H., Aramrattana, A., Bozzette, S., et al. (2007), ‘Preventing HIV infection among injecting drug users in high risk countries: an assessment of the evidence’, Institute of Medicine, Washington, DC.
• Turner, K. M. E., Hutchinson, S., Vickerman, P., Hope, V., Craine, N., Palmateer, N., May, M., Taylor, A., De Angelis, D., Cameron, S., Parry, J., Lyons, M., Goldberg, D., Allen, E. and Hickman, M. (2011), 'The impact of needle and syringe provision and opiate substitution therapy on the incidence of hepatitis C virus in injecting drug users: pooling of UK evidence', Addiction, 106: 1978–1988. doi: 10.1111/j.1360-0443.2011.03515.x
• WHO (2009). Guidelines for the Psychosocially Assisted Pharmacological Treatment of Opioid Dependence, Geneve.
• Wodak, A. (2004), ‘Letter from Dr Alex Wodak to Dr Zerhouni at the US National Institute of Health NIH’.
• Wright, N. M. and Tompkins, C. N. (2006), ‘A review of the evidence for the effectiveness of primary prevention interventions for hepatitis C among injecting drug users’, Harm Reduction Journal 6 (3), p. 27.

Explanation of terms used

 

About opioid injecting

Case definition (risks)

Risks at individual level

HIV, hepatitis B and C

Infectious diseases such as HIV and hepatitis B and C are among the most serious health consequences of drug use. The HIV epidemic among injecting drug users continues to develop differently across Europe. In the countries of the European Union, the rates of reported newly diagnosed cases of HIV infection in injecting drug users are mostly at stable and low levels, or in decline. However, in many of the eastern countries, rates have increased.

As well as HIV, hepatitis B and C, other infectious diseases, such as hepatitis A, sexually transmitted diseases (see below), tuberculosis, tetanus, botulism and human T-lymphotropic virus may disproportionately affect drug users.

Sexually transmitted diseases (STIs)

Sexually transmitted infections (STI) are a major global cause of acute illness, infertility, long-term disability and death, with severe medical and psychological consequences for millions of men, women and infants. Injecting drug users’ perception of sexual risk means that they are more at risk of developing STI.

Mortality

Drug-related mortality includes deaths that are directly caused by the pharmacological action of one or several substances (drug-induced deaths) and deaths that are indirectly caused by the use of drugs, often with other concurrent factors (e.g. accidents). Known causes of deaths include acute toxicity, traffic accidents in particular when combined with alcohol, violence, suicide among already vulnerable people, or chronic conditions due to repeated use (e.g. cardiovascular problems in cocaine users).

Overdose

Among Europeans aged 15–39 years, drug overdose accounted for 4 % of all deaths, in 2008. An overdose can occur if someone takes a larger dose of a drug than the body can tolerate. Overdoses can occur accidentally or deliberately, and they can be fatal or not fatal.

The risk of overdose with illicit drugs is particularly high when the drug content is not known. The risks are increased if the person has recently been through detoxification.

Risks at community level

Public nuisance and criminal activity

Public nuisance is identified defined as offences that affect the local community as a whole rather than the individuals. Drug-related public nuisance actually refers to a very wide range of ‘deviant behaviours Some activities are minor in their effect; others, can be perceived as causing major distress.

Aetiology

Unsafe injecting practices

Unsafe injecting practices include sharing of needles/syringes and other injection materials and there is a strong association between such practices and blood-borne infectious diseases such as HIV, HBV and HCV.

Infection of injection sites

Infections of injection sites can be common among injecting drug users and these may include: cellulitis, abcesses, skin ulcers, necrotising fasciitis, septic thrombophlebitis, and miscellaneous infections.

Unsafe sex

It has been shown that the sexual transmission of HIV among IDUs remains a significant concern, particularly in areas in which HIV or other STI epidemics are established, and where drug use intersects with sex work.

Prevalence

By the end of 2007, the incidence of reported HIV infection among injecting drug users appears to have remained low in most countries of the European Union, and the overall EU situation appears relatively positive in a global context.

Viral hepatitis and, in particular, infection caused by hepatitis C virus (HCV), is more highly prevalent than HIV in injecting drug users across Europe.

Population mortality rates due to drug-induced death vary widely between countries, ranging from 3 to over 85 deaths per million population aged 15–64 years, with an average of 22 deaths per million in Europe.

Interventions

Needle and syringe programmes (NSPs)

Needle and syringe programmes (NSPs) are interventions which provide sterile needles/syringes and other injecting equipment to injecting drug users. Delivery is diverse and can include a ‘primary’ fixed site, mobile and/or outreach services and ‘secondary’ access via community pharmacies, other health services and/or vending machines. NSPs operate across all EU Member States.

Opioid substitution treatment (OST)

Opioid substitution treatment is prescribed to dependent users to diminish the use and effects of illicit opiates. Community-based OST is available across all EU Member States and prison-based OST is officially available in the majority of Member States, although overall accessibility is limited.

Drug consumption rooms (DCRs)

DCRs offer a low-threshold environment to use pre-obtained drugs hygienically and to access targeted safer injecting advice and intervention in case of overdose. DCRs have been operating in Europe for more than 25 years and are available in 59 cities across Germany, Luxembourg, the Netherlands, Norway, Spain and Switzerland.

Peer naloxone distribution

Peer naloxone distribution (PND) or ‘take-home naloxone’ programmes provide the antagonist drug, with training to IDUs and/or carers to improve their capacity for effective intervention at opioid-related overdose.

Information, education and communication

Outreach and education rely on peers and local health workers to identify IDUs and provide education on preventing HIV and other infections, and to serve as guides to health and social services. Outreach workers may distribute information on HIV/AIDS, bleach kits for disinfecting injection equipment, and condoms.

While some programs are linked to needle and syringe exchanges or drug treatment clinics, outreach efforts often occur outside clinical settings and separate from other interventions.

Voluntary counselling and testing

Involves individuals actively seeking HIV testing and counselling at a facility that offers these services.

Outcomes

• Reduction of morbidity
• Reduction of incidence of HIV, HBV HCV, STI
• Reduction of mortality
• Reduction of criminality
• Reduction of public nuisance

Primary outcomes, measures

• reduction of risky behaviours (self-reporting injecting risk behaviour)
• reduction of overdoses and overdose-related morbidity
• reduction of imprisonment
• reduction of illegal activities
• reduction of public nuisance (opinion polls, victim surveys and ethnographic studies).

References

• Statistical bulletin
• EMCDDA (2009), 2009 Annual report: the state of the drugs problem in Europe, EMCDDA, Lisbon.
• EMCDDA (2010), Harm reduction: evidence and impacts, EMCDDA Monographs, Rhodes, T. and Hedrich, D. (editors), Publications Office of the European Union, Luxembourg.
• EMCDDA (2005), Drug-related public nuisance — trends in policy and preventive measures, EMCDDA Selected issues, EMCDDA, Lisbon.
• Arasteh K, Des Jarlais DC, Perlisa TE. Alcohol and HIV sexual risk behaviors among injection drug users. Drug and Alcohol Dependence Volume 95, Issues 1-2, 1 May 2008, Pages 54-61. doi:10.1016/j.drugalcdep.2007.12.008

Ongoing studies

• Ongoing studies will be added shortly.