Drug and Alcohol Findings home page in a new window EFFECTIVENESS BANK BULLETIN 30 October 2012

The entries below are our accounts of documents collected by Drug and Alcohol Findings as relevant to improving outcomes from drug or alcohol interventions in the UK. Unless indicated otherwise, permission is given to distribute these entries or incorporate passages in other documents as long as the source is acknowledged including the web address http://findings.org.uk. The original documents were not published by Findings; click on the Titles to obtain copies. Free reprints may also be available from the authors. If displayed, click prepared e-mail to adapt the pre-prepared e-mail message or compose your own message. The Summary is intended to convey the findings and views expressed in the document. Below may be comments from Drug and Alcohol Findings.

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Harm reduction value of needle exchange and methadone maintenance

Features studies which remind recovery-focused Britain of the harm reduction value of needle exchange and methadone maintenance services. First entry suggests these have curbed hepatitis C, an analysis based largely on the second entry, repeated here for convenience from an earlier bulletin. Australian analysts went further, calculating that needle exchanges will eventually save the health service money. Finally from Canada, a drastic way to demonstrate the value of a needle exchange – closing it.

Extend methadone and needle exchange but more needed to fight hepatitis C ...

Hepatitis C can be prevented by methadone plus needle exchange ...

Hepatitis C curbed by needle exchange but still rampant ...

Needle exchange closure demonstrates its worth ...


Can needle and syringe programmes and opiate substitution therapy achieve substantial reductions in hepatitis C virus prevalence?

Vickerman P., Martin N., Turner K. et al.
Addiction: 2012, 107, p. 1984–1995.
Unable to obtain a copy by clicking title? Try asking the author for a reprint by adapting this prepared e-mail or by writing to Dr Vickerman at peter.vickerman@lshtm.ac.uk.

Among the messages of this simulation model for the UK and other countries is the resilience of hepatitis C in the face of considerable investment in methadone and needle exchange services, that these have nevertheless helped and need to be maintained and if possible expanded, but also that further measures are required to substantially curtail the virus.

Summary A simulation model for the UK and other countries was used to estimate the impact on the spread of hepatitis C virus of scaling-up opiate substitution therapy Prescribing opiate-type drugs to people addicted to illegally obtained heroin or allied drugs as the basis of a programme to treat or mitigate the consequences of their addiction. and high coverage needle and syringe programmes. Offering sterile injecting equipment to injectors to prevent the spread of infection due to the re-use of equipment previously used by another injector who may be infected. Used equipment is often returned to the service, hence the term 'needle exchange'.

Data which fed in to the simulation derived from a synthesis of results from UK studies published since the year 2000 which related use of these services to hepatitis C infection among injectors outside prison. Six studies were found. From Birmingham, Bristol, Glasgow, Leeds, London and Wales. Two directly assessed the incidence of new infections by retesting To test whether they were HCV antibody-negative or positive. injectors a year later. The other four took measurements at a single point in time, but used a laboratory test Individuals who tested HCV RNA-positive among those who tested HCV antibody-negative were considered newly infected. to identify which injectors were relatively newly infected. In the repeat-test studies, injectors were considered to have been in opiate substitution treatment if this occupied at least six of the 12 months of the follow-up period. For the remaining studies the definition was being in treatment at the time of the test for infection. Injectors were considered to be 'highly covered' by needle and syringe programmes if these had supplied Over what was usually the last four weeks. them at least enough injecting equipment to have used a fresh set for each injection.

The conclusion was that when injectors were protected by one or other type of service to the degree set by the synthesis study, the chances of their becoming infected were halved relative to the risk faced by injectors who had not adequately participated in either type of service. When injectors were protected by both, their risk of infection was just a fifth of that faced by injectors who had used neither to the degree set by the study, and this time the risk reduction was statistically significant.

These values were incorporated in the featured simulation study as the risk reduction effect of being in substitute prescribing and/or receiving enough sterile equipment for each injection in the past month. Data from GPs supported the assumption that on average patients stayed in treatment for eight months. In the absence of adequate data, the same assumption was made for high-coverage needle and syringe provision. The simulation was run for the UK specifically and for countries in general, varying the proportion of injectors engaged in either or both types of programmes. At issue was the effect of increasing these proportions, simulating the impact of scaling up service provision.

Main findings

The all-countries simulation assumed a baseline of no injectors receiving either type of service, and either 20%, 40% or 60% chronically infected with hepatitis C. As long as sustained for at least 15 years, recruiting 6 in 10 injectors in to adequate injecting equipment provision and substitute prescribing treatment was calculated to reduce the proportion infected with hepatitis C by a third. If just 4 in 10 were recruited, this degree of reduction would take 20 years. In the short-term the starting proportion infected made little difference, but over 20 years the interventions had less impact if introduced when a very high proportion of injectors were already infected. Varying assumptions about the effectiveness of the interventions was calculated to make a big difference to their impacts on the epidemics.

For the UK, data supported the assumed baseline of 40% of injectors chronically infected with hepatitis C and half of all injectors engaged in either opiate substitute prescribing programmes or high-coverage needle and syringe provision. The simulation extrapolated back to a hypothetical zero access to substitute prescribing and adequate needle exchange, leading to an estimate that assumed current service coverage of 50% may have reduced what would have been a 65% infection rate among injectors to 40%.

It was calculated that over the long term, recruiting just another 10% (up from 50% to 60%) of UK injectors to these programmes would result in modest further reductions in infection rate, but that substantial progress would require scaling up these interventions so that both reach not half the injectors, but at least 8 in 10. This level sustained for 10 years meant the infection rate would drop from 40% to 30%, and for 20 years, to about 20%. Achieving increased coverage means recruiting more injectors to these programmes and/or retaining those who do use them for longer. Without increased retention, the recruitment rate has to be much higher. For example, at eight months retention, to get 8 in 10 injectors in to these programmes requires over half those not yet attending to join each month. If retention doubles to 16 months, then just under 30% need to join each month – still over twice the assumed 12.5% baseline, but a more achievable figure.

Again, varying assumptions about the effectiveness of the interventions was calculated to make a big difference to their impacts on the infection rate. Even more influential was varying assumptions about what proportion of injectors stop injecting each year from 5% up to 20%; interventions have greater impact the shorter the typical injecting career.

The authors' conclusions

This analysis suggests that opiate substitution therapy and high coverage needle and syringe programmes can reduce the prevalence of hepatitis C among injectors, but also that reductions are frequently modest and require many years of sustained intervention coverage. For instance, cutting prevalence by a third over 10 years would usually require over 60% of injectors to be engaged in these programmes. Projections for countries which already have sustained high coverage (such as the UK and Australia) suggest that many infections have been averted. For example, without such interventions 65% of UK injectors would have been chronically infected with hepatitis C, amounting to 50,000 extra infections in England and Wales. But further substantial reductions (down by over half) are unlikely unless both interventions can be scaled-up to reach not 50%, but over 80% of injectors for at least 20 years.

In the face of inadequate progress in curtailing hepatitis C, broadly one may recommend extending existing interventions to more injectors, or argue that this will not be enough and other interventions are required. Among these may be vaccination if this becomes available, treating infection, promoting ways to take drugs other than injecting, or distributing less transmission-prone equipment such as low dead space syringes.

Where conventional substitute and equipment supply programmes already reach a high proportion of injectors, the featured simulation suggests that additional alternative measures are indeed required to make substantial further progress. Only a very ambitious programme, for example recruiting 30% of injectors per month to these interventions and typically retaining them for 16 months, would see hepatitis C prevalence in nations such as the United Kingdom halved within 20 years. Such an expansion is unlikely to be sustained or funded. In contrast, where substitute prescribing and equipment supply programmes currently reach few injectors, initial efforts Ways to do this for substitute prescribing include psychosocial therapies, individualised treatment, providing free treatment and transport, other incentives, and flexible and higher dosing. Ways to do this for equipment supply include removing limitations on what and how much can be supplied, allowing injectors to supply each other with sterile equipment, and more and varied supply points. Other components could also be important for maximising behaviour change while in contact with these interventions. should focus on scaling up both interventions. In the long term, however, even in these areas other interventions such as treating infected patients will also be needed to substantially reduce the prevalence of hepatitis C.


Findings logo commentary The simulation illustrates why a country such as the UK which started with a high level of hepatitis C infection still has high levels despite considerable investment in needle exchange and methadone and buprenorphine maintenance. Without this investment, tens of thousands more people would have had their lives blighted by infection, but reducing this number by much more still would require a degree of commitment on the part both of injectors and health service funders which seems unlikely.

Sustaining and if possible increasing engagement in needle exchange and methadone and buprenorphine maintenance programmes is essential not just to contain hepatitis C, but also HIV, and for reasons not to do with infection control at all, but more will be needed. One clue to what comes from the study's finding that decreasing the length of injecting careers – which in itself would reduce the number of infections – also augments the impact of the interventions. If recovery-oriented national polices in Britain do work, the result should indeed be to curtail drug use and injecting careers. It has also recently become apparent that injecting is falling out of favour, another way in which infection could be reduced and service coverage increased without extra resources. These comments are expanded on below.

Sophisticated as they are, the calculations made by the featured analysis depend on an association between infection rates and adequate needle exchange and substitute prescribing which could have been due to other factors. Conceivably, for example, injectors concerned and stable enough to stay in treatment and to make regular use of needle exchanges would have found other ways to avoid infection, even if exchanges and treatment were unavailable. In this scenario, it would not be the services which were active ingredients, but the characteristics of the injectors who tended to use them most. It should also be remembered that one half of the intervention duo modelled in the study – opiate substitute prescribing – is applicable only to patients addicted to these types of drugs. If sustained over many years, injecting crack increased the infection rate in the featured model, and the more primary crack injectors there are, the lower the proportion of injectors who might be attracted in to, accepted by, and retained by opiate substitute prescribing programmes.

High coverage is the key but can it be achieved?

An important finding from the study is that the effectiveness of maintenance and needle exchange in preventing infection is a major influence on how many injectors become infected. Not just sustaining and extending but also optimising both services is important. As emphasised by Findings in a series of reviews on hepatitis C and needle exchange, this and other bodies of work stress that the best way to curb the spread of HIV and hepatitis C among injectors is high coverage supply of injecting equipment, enough and sufficiently easily available for a fresh set to be used each time, allied with high coverage substitute prescribing.

However, complete coverage in terms of the supply of injecting equipment is very far from the norm in Britain, with the result that at the end of the first decade of the 2000s hepatitis C was spreading more rapidly than in the early 2000s, infecting a quarter of injectors within three years of their starting to inject.

Given funding constraints and the current policy emphasis on recovery from addiction and abstinence rather than harm reduction, it may be unrealistic to expect a further major contribution to stemming the hepatitis C epidemic from services intended to ameliorate damage from continued injecting. What would help is if their workload could be reduced because (aided or not by treatment) drug users themselves turn away from injecting, by far the most important route for infection. From population estimates and trends in the treatment caseload, it seems this may be happening, an estimated 137,000 injecting drug users in England in 2004–05 falling to 117,000 in 2006–07.

NICE's verdict and other studies

The type of models exemplified by the featured analysis make estimates based on what ought to happen given current knowledge and best guesses, rather than what has actually happened. They have large margins for error in themselves and also because what they predict may not happen in reality. Also they form a limited basis for determining health policy because they do not extend to estimating whether spending on syringe distribution and prescribing programmes might save/improve more lives if used in another health sector entirely. However, within the limited remit of preventing infections among injectors, these programmes take pride of place, especially when opiate-type drugs account for a major part of injecting.

Despite the uncertainties, the results of such simulations, and those of studies of what actually happens, were enough to convince Britain's National Institute for Health and Clinical Excellence (NICE) that commissioners should aim to provide every injector with all the equipment they need to use a sterile set each time, the definition of high coverage in the featured analysis. The NICE committee reached these conclusions partly on the basis of a cost-effectiveness analysis. It concluded that extending adequate needle exchange to a higher proportion of injectors would usually save and improve lives at well below the cost to the health service normally considered to justify the expenditure. Also like the featured analysis, this work suggested that while increasing the coverage of syringe distribution and substitute prescribing programmes is sufficient to control HIV, it will not on its own substantially reduce hepatitis C infection; this requires a multi-faceted programme, including for example these interventions plus treatment of patients already infected with hepatitis C.

The featured study's results for Britain are likely to be broadly applicable to countries such as Australia with similar policies, services, drug use patterns and rates of HIV and hepatitis C infection, and vice versa. As in the featured analysis for Britain and hepatitis C, a recent simulation for Australia estimated that without needle and syringe distribution programmes, in 2000–2010 there would have been many more HIV and hepatitis C infections. Distribution programmes had it was calculated prevented 192–873 HIV infections (34–70% of what would have been the total) and 19,000–77,000 hepatitis C infections (15–43% of what would have been the total).

Unlike the featured analysis, the Australian study went on to estimate that needle and syringe distribution programmes were a highly cost-effective way to extend and improve lives by preventing infection-related illnesses including AIDS and liver disease. Also, cumulative costs savings over the life of injectors who would otherwise have been infected was estimated to mean that eventually each dollar spent on these programmes in 2000–2010 would have saved from 1.3 to 5.5 times as much in averted healthcare costs.

Turning to opioid substitute prescribing, a systematic review of its impact on HIV concluded that this treatment reduces drug-related behaviours with a high risk of HIV transmission. Four studies assessed relationships between the proportions of people who actually became HIV positive (seroconversion) and their participation in methadone treatment. All found that participation as such, or more extended or continuous participation, was associated with a lower rate of seroconversion. However, impacts on hepatitis C are much less well established.

Last revised 29 October 2012. First uploaded 24 October 2012

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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.

Turner K.M.E., Hutchinson S., Vickerman P. et al.
Addiction: 2011, 106, p. 1978–1988.
Unable to obtain a copy by clicking title? Try asking the author for a reprint by adapting this prepared e-mail or by writing to Dr Hickman at matthew.hickman@bristol.ac.uk.

Together studies recently conducted across the UK suggest that consistent participation in methadone maintenance treatment plus adequate access to fresh injecting equipment has prevented many hepatitis C infections, supporting calls for needle exchange to be expanded and methadone treatment sustained.

Summary For drug injectors, opiate substitution therapy reduces drug dependence and the frequency of injecting while providing hygienic injecting equipment through needle and syringe programmes reduces unsafe injecting using shared syringes. These interventions have been shown to reduce self-reported injecting risk behaviour, but there is little direct evidence of impact on the incidence of hepatitis C infection. By pooling data from studies across the United Kingdom, this study aimed to determine whether opiate substitution therapy and needle and syringe programmes, singly or in combination, can reduce the transmission of hepatitis C among drug injectors.

The analysts searched for studies conducted in the UK and published since the year 2000 which related hepatitis C infection among injectors outside prison to their participation in opiate substitution therapy and/or needle and syringe programmes. Six such studies were found of 2986 injectors in total, conducted in Birmingham, Bristol, Glasgow, Leeds, London and Wales. Two of the studies were follow-up studies which directly assessed the incidence of new infections by retesting To test whether they were HCV antibody-negative or positive. injectors a year later. The other four which took measurements at a single point in time used a laboratory test Individuals who tested HCV RNA-positive among those who tested HCV antibody-negative. to identify which injectors were relatively newly infected. For the follow-up studies injectors were considered to have been in opiate substitution treatment if this treatment occupied at least six of the 12 months of the follow-up period. For the remaining studies the definition was currently being in treatment. Injectors were considered to be 'highly covered' by needle and syringe programme provision if from these sources they had obtained at least enough sterile injecting equipment to have used a fresh set for each injection. These categories were then combined to form three levels of harm reduction coverage:
full coverage by both consistently being in opiate substitution therapy and high coverage needle and syringe programmes;
partial coverage by consistently being in opiate substitution therapy or high coverage needle and syringe programmes;
minimal coverage, neither consistently accessing opiate substitution therapy nor obtaining high coverage of injecting equipment needs from needle and syringe programmes.

Main findings

Across the six studies the proportions of injectors infected with hepatitis C ranged from 70% in Glasgow to 26% in Wales. The estimated proportions who became or were newly infected ranged from 5% to 40% per year. 57% had recently been or were (as defined by the study) in opiate substitution therapy and 67% were highly covered by needle and syringe programmes.

Interest centred on the 1457 injectors who (for the follow-up studies, initially) tested negative for hepatitis C antibodies. Only these injectors could be shown to have become newly infected, either by a retest a year later in the follow-up studies, or by a further hepatitis C RNA test in the studies conducted at a single point in time. Missing data and the exclusion of people who had not injected during the relevant periods reduced the numbers in each analysis to around 1000.

In three of the six relevant studies, being or having been in opiate substitution treatment was associated with a lower risk of becoming newly infected with hepatitis C. Though there were inter-study differences in the strength and direction of this link, these were not statistically significant, meaning the results of the studies could be pooled. These pooled results revealed that across the six studies there was a statistically significant association between opiate substitution treatment and a lower risk of becoming infected. Similarly across the five relevant studies, high coverage participation in needle and syringe programmes was also linked with a lower risk of becoming infected. In both cases the effect size A standard way of expressing the magnitude of a difference (eg, between outcomes in control and intervention groups) applicable to most quantitative data. Enables different measures taken in different studies to be compared or (in meta-analyses) combined. Based on expressing the difference in the average outcomes between control and experimental groups as a proportion of how much the outcome varies across both groups. The most common statistic used to quantify this difference is called Cohen's d. Conventionally this is considered to indicate a small effect when no greater than 0.2, a medium effect when around 0.5, and a large effect when at least 0.8. indicated a medium-strength effect.

A finer grained analysis assessed whether injectors were at lower risk of infection when they were partially covered by either opiate substitution treatment or high coverage needle and syringe programmes, but not both. After differences in risk profiles That is, whether the injector was a woman, had recently been homeless or injected crack, or had injected for over 2.5 years. had been accounted for, in both cases the odds of becoming infected versus remaining uninfected were halved relative to the risk faced by injectors who had not adequately participated in either type of harm reduction service. However, in neither case was the risk reduction statistically significant. When injectors had used both types of services, their risk of infection was just a fifth of that faced by injectors who had used neither to the degree set by the featured study, and this time the risk reduction was statistically significant. The raw numbers were 8 of 392 fully covered injectors becoming infected versus 13 of 120 who had used neither service to the set degree.

Instead of actual infections, similar analyses assessed the links between harm reduction coverage and behaviour which put the injector at risk of infection: specifically, sharing needles over the past month and frequent injecting. Injectors who had used both opiate substitution treatment and high coverage needle and syringe programmes to the degree set by the study were on both counts at lower risk than those who met neither service access criterion. They were half as likely to have shared versus not shared and they injected 21 times fewer per month. Among the partially covered injectors who used one service but not the other, the only statistically significant result was a reduction in the frequency of injecting amounting to 13 times a month among opiate substitution patients.

The authors' conclusions

By pooling UK data the study showed that opiate substitute treatment (in Britain, mainly using methadone) and high coverage needle and syringe programme participation can reduce the transmission of hepatitis C among injectors. After adjusting for important influences on the risk of infection (such as gender, homelessness and crack use), access to either type of service approximately halved the risk of infection, and the combination of both could reduce risk by up to 80%. The true effect of opiate substitute treatment may have under-represented, since most of the studies recruited only current injectors, missing the risk reduction achieved by those helped to stop injecting altogether by treatment. In line with previous evidence, the study also showed that this combination of services was associated with lower levels of infection risk behaviour in the form of injecting and the sharing of injecting equipment.

The analyses did not assess the impact of using needle and syringe programmes as such, but use at a level adequate to meet the injector's need for fresh equipment. In areas where hepatitis C is very common among injectors, even infrequent infection risk behaviour is enough to sustain transmission. Preventing it requires not just use, but high levels of use of needle and syringe programmes, preferably allied with opiate substitute treatment. Under these conditions, these harm reduction interventions are effective in intercepting transmission of the virus. How much more will be required to actually drive down levels of infection across the injecting population remains to be determined.


Findings logo commentary The featured analysis bolsters the contention (details below) that fully implemented and multi-pronged harm reduction services can dent the transmission of hepatitis C, and supports calls for current services (especially needle exchange provision) to be upgraded to meet this challenge.

One of its strengths is that as well as demonstrating a link between new infection and service use, it also showed how this link might operate by reducing the frequency of injecting and the proportion of injectors who continue to share injecting equipment, reducing opportunities for the virus to be transmitted. Completing the expected causal chain from service use, through behaviour change, to actual infection, adds credibility to the assumption that the links between service use and infection found by the study are due to an effect of the interventions.

It remains the case however that this conclusion is based on an association which could have been due to other factors. Conceivably, for example, injectors concerned and stable enough to stay in treatment and to make regular use of needle exchanges would have found other ways to avoid infection, even if exchanges and treatment were unavailable. In this scenario, it would not be the services which were the essential factor, but the characteristics of the injectors who tended to use them most.

For example, of the six studies on which the featured analysis was based, one in Wales was important because it was one of the two to follow-up uninfected injectors and see if later (in this case, a year later) they had become infected with hepatitis C, and because its results contributed considerably to the positive findings on opiate substitution treatment. However, the researchers admitted that "it is possible that we failed to identify differences between those in and out of treatment. Of particular concern is that being in [treatment] might arguably reflect more care seeking and lower risk behaviour ... rather than an effect of treatment per se." Also this study was able to follow up just 286 of the 516 injectors who initially tested as uninfected.

Another study in Bristol contributed considerably to the positive findings on needle exchange provision. Its findings were based largely on just 14 individuals who showed evidence of recent infection. The sample was asked about their exchange use over the past week, but the infection could have occurred months before. It may be the case, as the authors say, that "their service use will probably have changed little over this relatively short period", but the salient issue is whether they had attended exchanges with sufficient regularity and diligence to get all the equipment they needed to use a fresh set for each injection, a condition presumably easier to dip in and out of than attending versus not attending. But the major unanswered question is in what ways the high coverage exchange users differed from those who did not get enough for a fresh set each time, and whether their diligence would have led them to protect themselves in other ways such as effective cleaning, re-using only their own equipment, or sharing only with trusted infection-free associates.

In line with other research

The findings confirm research reviewed by Findings which indicated that in respect of hepatitis C, "Trickle-feed needle exchange does not work, or not well enough. It has to be nearer a flood. Hepatitis C demands strategies which aim to eliminate even occasional risky sharing and which extend to all the equipment directly or indirectly in contact with an injector’s blood, and all the ways this might happen."

As in the featured study, the review also found evidence that treatment and needle exchange exert a synergistic impact on risk. By reducing the frequency of injecting, oral opiate substitution programmes also reduce the opportunities for sharing equipment and for viral spread. Meantime, the role of exchanges is to see that uncontaminated equipment is used for each remaining injection and to remove potentially contaminated equipment. By reducing the number of injections, treatment should make it easier to meet the reduced demand for injecting equipment. Treatment can also address the lifestyle and psychosocial factors which thwart the efforts of exchanges. Prescribing injectable drugs too may help. Even if it does not reduce injecting frequency, sourcing injectable drugs from a doctor divorces injectors from the shared drug procurement and consumption arrangements which characterise illegal drug use, making it less likely that they will also share injecting equipment. Evidence for a synergistic impact was apparent in the early years of needle exchange in Britain, when injectables were more widely prescribed than today. Facilitating access to this treatment was probably one of the main ways exchanges reduced infection risk. In the USA, studies have found that by reducing the frequency of injecting, treatment augments the risk reduction impact of attending exchanges, whose main effect is not to reduce injecting, but the sharing of injecting equipment.

Findings from the featured study parallel those from Amsterdam, where over the decade from 1985 to 2005 injectors who had more fully implemented harm reduction (were being prescribed at least 60mg daily of methadone and had either stopped injecting or injected only with needles from needle exchanges) were less likely to become infected with HIV or hepatitis C than continuing injectors who did not use exchanges and were not in methadone treatment. In contrast, less complete harm reduction access – lower doses of methadone and/or not fully relying on exchanges for one's syringes – did not significantly reduce the rate of new infections. Similar findings have also emerged from Baltimore in the USA, where syringe exchange participants who entered treatment reduced their drug use, crime and injecting more than syringe exchange alone was able to achieve.

Policy implications

The findings of the featured study were fed in to a simulation model for the UK. This extrapolated back to a hypothetical zero access to substitute prescribing and adequate needle exchange, leading to an estimate that current service provision levels may have reduced what would have been a 65% infection rate among injectors to 40%. But to make further substantial progress would it was calculated require scaling up these interventions so that both reach not half the injectors in the UK, but at least 8 in 10. To do this would probably require both considerably more injectors to start using these programmes and for them to stay considerably longer.

Among the implications of these findings is that needle exchange services and commissioners should prioritise adequate provision of injecting equipment, an objective known to be furthered by liberal rather than restrictive distribution policies. Another is that exchanges can make their provision more effective by finding ways to promote treatment entry by their clients, like co-location with treatment services and active referral. These were among the recommendations made in 2009 by Britain's National Institute for Health and Clinical Excellence, in a report which saw a triumvirate of services – high coverage needle exchange, substitute prescribing, and the treatment of hepatitis C infection – as the foundation of an anti-infection strategy.

How far England (and probably even more so other UK nations) is from implementing such a strategy was revealed by an audit of the impact of the national hepatitis C action plan launched in 2004. At the end of the first decade of the 2000s hepatitis C was spreading more rapidly than in the early 2000s, infecting a quarter of injectors within three years of their starting to inject.

This means that the reduction Down across Britain from about 60% in the past month in the early 2000s to 37% in 2009 and 40% in 2010. in the sharing of injecting equipment seen among drug injectors surveyed at drug services has been insufficient to dent the spread of the highly transmissible hepatitis C virus. It has been estimated that to get to the point where less than 1 in 10 injectors in London are infected with hepatitis C would require the average injector to cut their sharing of used syringes from 16 times a month to one or two times, and that the impact of even this kind of achievement would be jeopardised unless sharing reductions extended to very recently initiated injectors.

Such a scenario is currently well beyond the capacity of available services. Exchange services in Britain and elsewhere are commonly patchily provided, under-funded and hampered by formal or informal restrictions on their abilities to 'flood the market' with hygienic injecting equipment. In the mid-2000s, in England access to sterile injecting equipment from needle exchanges fell well short (on average just one syringe per exchange user every two days) of the level needed to permit use of a fresh needle each time, and only a minority provided some other equipment such as sterile water. At about the same time in Scotland, syringe supplies from exchanges were even more limited – at best an average of one per user every three days, though since then distribution may have modestly increased.

When the entire population of injectors is considered whether or not they attend exchanges, the shortfall is bound to be greater still. For example, in 2000/1 exchanges in Brighton and Liverpool supplied enough equipment for just over 1 in 4 injections in their areas and in London 1 in 5, if anything less than a national estimate for England for 1997.

Last revised 25 October 2012. First uploaded 14 October 2011

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Top 10 most closely related documents on this site. For more try a subject or free text search

Can needle and syringe programmes and opiate substitution therapy achieve substantial reductions in hepatitis C virus prevalence? STUDY 2012

Prevention and control of infectious diseases among people who inject drugs DOCUMENT 2011

The primary prevention of hepatitis C among injecting drug users REVIEW 2009

The effectiveness of opioid maintenance treatment in prison settings: a systematic review STUDY 2012

Community loses from failure to offer maintenance prescribing in prisons DOCUMENT 2013

Hepatitis C infection among recent initiates to injecting in England 2000–2008: Is a national hepatitis C action plan making a difference? STUDY 2011

Optimal provision of needle and syringe programmes for injecting drug users: a systematic review REVIEW 2010

Harm reduction flood needed to contain the hepatitis C epidemic HOT TOPIC 2014

Effect of motivational interviewing on reduction of alcohol use STUDY 2010

Substitution treatment of injecting opioid users for prevention of HIV infection REVIEW 2011



Estimating the cost-effectiveness of needle-syringe programs in Australia.

Kwon J.A., Anderson J., Kerr C.C. et al.
AIDS: 2012, 26, in press.
Unable to obtain a copy by clicking title? Try asking the author for a reprint by adapting this prepared e-mail or by writing to Dr Wilson at dwilson@unsw.edu.au.

Latest mathematical model from Australia probably broadly applicable also to the UK suggests that needle and syringe programmes have cost-effectively saved/improved lives, and in the long run save the health service money due to averted HIV and hepatitis C infections. But in both countries adequately curbing hepatitis C requires much more.

Summary Australia introduced needle and syringe distribution programmes in 1986, offering sterile injecting equipment to injectors to prevent the spread of infection (mainly HIV and hepatitis; of the latter, hepatitis C is the variant of the greatest concern) due to the sharing of used equipment. HIV prevalence among injectors in Australia has since remained relatively low and stable at about 1%, but hepatitis C prevalence has remained at 50–70%. At present, there are over 3000 needle and syringe distribution programmes across Australia. Based on a mathematical model, this study aimed to estimate the degree to which these programmes have averted HIV and hepatitis C infections, resultant savings in health care costs, and how much the programmes cost per year they extended life, adjusted for the quality of those years (QALYs) – in other words, whether they represented a good investment in health terms.

To do this it was necessary to estimate what would have happened had there been no needle and syringe distribution programmes, and to contrast this with estimates derived from what has actually happened. In these calculations a key variable was the extent to which injectors risked becoming infected by using injecting equipment previously used by someone else – the rate of 'receptive sharing'. Reducing this rate was assumed to be the main way needle and syringe distribution programmes curb infection.

Main findings

Nationally in Australia during 2000–2010, the proportions of injectors who in surveys said they had re-used syringes/needles after another injector in the past month varied between 15% and 17%. These represent rates in the presence of a substantial needle and syringe distribution programme. Based on data from the 1970s and 1980s, without any or with few such programmes the sharing rate was 70–90%. It was assumed that by 2000–2010 increased awareness of blood-borne infections would have reduced this to 25–50% even without equipment distribution programmes.

When these figures were fed in to the mathematical model, resultant estimates for 2000–2010 with current needle and syringe distribution programmes were close to actual figures, for example, estimating that proportion of injectors infected with HIV would remain low, reaching 1.1% in 2010, while for hepatitis C the proportion would vary between 50% and 60%.

Without needle and syringe distribution programmes, the model estimated that both HIV and hepatitis C infection would have been substantially more common, reaching prevalence levels among injectors of 1.2–1.5% and 66–80% respectively. The higher estimates are based on the assumption that the sharing rate before needle and syringe provision programmes was 25%, the lower estimates that it was 50%. This means that distribution programmes prevented 192–873 cases of HIV infection (34–70% of what would have been the total) and 19,000–77,000 hepatitis C infections (15–43% of what would have been the total).

Due to people who would otherwise have been infected living longer and staying healthier, during these years preventing these infections would have resulted in a gain of 20,000–66,000 years of life adjusted for the quality of those years (QALYs). Over the lifetime of the same people, a further 48,000–145,000 QALYs would have been gained.

In 2000–2010 needle and syringe distribution programmes cost about 245 million Australian dollars. Without them more people would have had to have been treated for HIV and hepatitis C infections and for consequent illnesses including AIDS and liver disease. The result would have been an extra 70–220 million dollars of health care spending during these years and a further 340–950 million over the lifetime of those infected. Including the cost of the programmes themselves, this means that in 2000–2010 needle and syringe distribution programmes saved one year of life adjusted for quality at a total cost to the health service of from 416 to 8750 dollars, well within the 50,000 dollars commonly accepted in Australia as the maximum for a health intervention to be considered cost-effective. Cumulative costs savings over the life of the injectors who would otherwise have been infected means that by year 2032 the programmes would have saved more than they cost. Eventually each dollar spent on these programmes in 2000–2010 would have saved from 1.3 to 5.5 times as much in averted healthcare costs.

The authors' conclusions

Incorporating available biological, behavioural, and programme data in to a mathematical model suggested that needle and syringe distribution programmes are likely to have averted a substantial number of HIV and hepatitis C infections among drug injectors, and that because of this they cost-effectively save and improve lives in the short-term, and save total healthcare costs over the longer term. These calculations do not include other possible programme benefits such as preventing injecting-related injuries, psychosocial support, and referral to medical, treatment and other services.

Distribution programmes have helped keep the level of HIV infection among injectors very low, but hepatitis C remains widespread, probably due to its greater transmissibility and the fact that it was already common before the programmes were introduced. Despite programmes reaching a high proportion of injectors in Australia, sharing of injecting equipment remains common among new injectors and is strongly associated with an increased risk of becoming infected with hepatitis C.

The most crucial component of the analysis was the assumption that sharing rates would have been considerably higher without needle and syringe distribution programmes. Additional to the 70–90% rate recorded in pre-programme studies, studies internationally support this assumption. For example, in Canada the sharing rate increased from 10% to 23% following closure of the only fixed needle and syringe distribution programme in the city of Victoria, but was unchanged in Vancouver, where the programme remained open.

Other types of programmes and notably the prescribing of drugs to substitute for illegal opiate-type drugs can also curb infections, but the latter's potential impact depends on the proportion of injectors who inject these types of drugs – in Australia, only about 30%.


Findings logo commentary With similar policies, services, drug use patterns and rates of HIV and hepatitis C infection, the results of this simulation study part-funded by the Australian government are likely to be broadly applicable to Britain. The credible implication is that in both countries needle and syringe programmes have cost-effectively saved/improved lives, and in the long run will save the health service money due to averted HIV and hepatitis C infections. From this it follows that at least sustaining these programmes is a prudent cost- and life-saving measure.

However, the featured simulation had to make some bold assumptions to complete its calculations. Top among these is, as the authors acknowledge, the assumption that without needle and syringe programmes the proportion of injectors who regularly (implied by the short one-month recall period) re-used this equipment after another injector would have been from 50% to over three times higher, and that such sharing would have remained the norm throughout 2000–2010.

Seemingly contrary to this assumption is the data they present In figure 1b. which shows that nationally in Australia the number of syringes distributed per injector has varied over threefold from about 50 to about 180 without any noticeable trend in the associated sharing rate. Effectively the analysts extrapolated this rate back to a hypothetical near 0 number of syringes per injector, and assumed that once coverage is this low the sharing rate would possibly triple. Why this would happen when a threefold variation further up the syringe distribution scale appeared to make little difference is unclear. Another complicating factor is the 'heroin drought' which disrupted drug use patterns in Australia from the end of year 2000. This means the key comparison of sharing rates in the 1970s and 1980s with those in the 2000s straddles a disjunction which brought other important influences in to play apart from needle and syringe distribution programmes.

For the featured simulation needle and syringe provision works by reducing the proportion of injectors who re-use syringes/needles after another injector. An alternative assumption made in an earlier paper from the same research team is that they work (or at least, having more of them providing more equipment works) by cutting the number of times each set of equipment gets re-used – effectively, the number of bodies a set of equipment has been in and out of before a given injector uses it. Epidemics of infection will be sustained if on average each infected injector results in the infection of at least one other injector. According to this earlier paper, reaching this point would require a post-infection injecting career of nearly 12 year for HIV but just over two years for hepatitis C. Achieving the former is within reach of current services, but the latter is well beyond their capacity to shorten addiction careers.

The challenge of hepatitis C

The resilience of hepatitis C in the face even of substantial intervention resources was also one conclusion of a modelling exercise for the UK, based on a study which collated UK evidence to reach the conclusion that consistent participation in methadone maintenance treatment plus adequate access to fresh injecting equipment (enough for a sterile set for each injection) has prevented many hepatitis C infections.

After adjusting for important influences on the risk of infection, the study found that access to either type of service had approximately halved the risk of infection, and the combination of both could reduce risk by up to 80%. Like the featured analysis, the model used this and other data to extrapolate back to a hypothetical zero access to substitute prescribing and adequate needle exchange, leading to an estimate that current service provision levels may have reduced what would have been a 65% infection rate among injectors to 40%. But making further substantial progress would, the simulation calculated, require scaling up these interventions so that both reach not half the injectors in the UK, but at least 8 in 10. To do this would probably require both considerably more injectors to start using these programmes and for them to stay considerably longer.

Though in line with other findings, this conclusion rests on studies which were unable to eliminate other possible influences on whether someone became infected with hepatitis C. Conceivably, for example, injectors concerned and stable enough to stay in treatment and make regular use of needle exchanges would have found other ways to avoid infection, even if exchanges and treatment were unavailable. However, the study does give an indication of the magnitude of the challenge of controlling hepatitis C.

For more on the challenge of hepatitis C see this series of Findings reviews which stress that the best way to curb the spread of HIV and hepatitis C among injectors is high coverage supply of injecting equipment, enough and sufficiently easily available for a fresh set to be used each time.

Aim for a fresh set of equipment for each injection

The type of models exemplified by the featured analysis make estimates based on what ought to happen given current knowledge and best guesses, rather than what has actually happened. They have large margins for error in themselves, and also because what they predict may not happen in reality. Also they form a limited basis for determining health policy because they do not extend to estimating whether spending on syringe distribution programmes might save/improve more lives if used in another health sector entirely. However, within the limited remit of preventing infections among injectors, these programmes take pride of place alongside (when opiate-type drugs account for a major part of injecting) opiate substitute prescribing treatment.

Despite the uncertainties, their results and those of other studies were enough to convince Britain's National Institute for Health and Clinical Excellence (NICE) that commissioners should aim to provide every injector with the equipment they need to use a sterile set each time. The NICE committee reached these conclusions partly on the basis of a cost-effectiveness analysis. Like the featured analysis, it concluded that extending adequate needle exchange to a higher proportion of injectors would usually save and improve lives at well below the cost to the health service normally considered worth the expenditure. This work also suggested that while increasing the coverage of syringe distribution and the recruitment rate in to substitute prescribing programmes are sufficient to control HIV, they will not substantially reduce the prevalence or incidence of hepatitis C infection. According to the committee, this requires multi-faceted interventions – not just more needle exchange and prescribing but also, for example, more widespread treatment of hepatitis C infection.

However, complete coverage in terms of the supply of injecting equipment is very far from the norm in Britain, with the result that at the end of the first decade of the 2000s hepatitis C was spreading more rapidly than in in the early 2000s, infecting a quarter of injectors within three years of their starting to inject.

Given funding constraints and the current policy emphasis on recovery from addiction and abstinence rather than harm reduction, it may be unrealistic to expect a further major contribution to stemming the hepatitis C epidemic from services intended to ameliorate the damage from continued injecting. What would help is if their workload could be reduced because (aided or not by treatment) drug users themselves turn away from injecting, by far the most important route for infection. From population estimates and trends in the treatment caseload, it seems this may be happening, an estimated 137,000 injecting drug users in England in 2004–05 falling to 117,000 in 2006–07.

Thanks for their comments on this entry in draft to David Wilson of the National Centre in HIV Epidemiology and Clinical Research at the University of New South Wales in Australia, and to Tim Bingham, chairperson of the Irish Needle Exchange Forum. Commentators bear no responsibility for the text including the interpretations and any remaining errors.

Last revised 26 October 2012. First uploaded 17 October 2012

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An examination of injection drug use trends in Victoria and Vancouver, BC after the closure of Victoria's only fixed-site needle and syringe programme.

Ivsins A., Chow C., Macdonald S. et al.
International Journal of Drug Policy: 2012, 23(4), p. 338–340.
Unable to obtain a copy by clicking title? Try asking the author for a reprint by adapting this prepared e-mail or by writing to Dr Ivsins at aivsins@uvic.ca.

Until June 2008 Victoria in Canada had a comprehensive extended hours needle exchange at a fixed site in the city. Neighbourhood pressure led to closure, creating a natural experiment in the withdrawal of services. The result seemed to be more sharing of injecting equipment entailing a greater risk of infection.

Summary Needle and syringe distribution programmes offer infection-free injecting equipment to injectors to prevent the spread of infection (mainly HIV and hepatitis; of the latter, hepatitis C is the variant of the greatest concern) due to the sharing of used equipment.

Since 1988 such services have been offered in the city of Victoria, capital of the province of British Columbia in Canada, but at the end of May 2008 pressure from local businesses and residents led to the closure of the city's only fixed-site programme. Since then services have been offered through a variety of mobile and satellite programmes, but the number of needles distributed dropped by about 40% and remained lower than before closure. This gap in service remained despite 13% of the city's injectors being infected with HIV and 63% with hepatitis C.

Over the same period the fixed-site needle and syringe distribution programme in the nearby city of Vancouver continued to operate, along with mobile services and premises in which injectors can legally inject under medical supervision.

The featured study took this opportunity to investigate the consequences of the closure in Victoria, contrasting trends in the sharing of injecting equipment there before and after the closure with what happened during the same period in a city which had no such disruption in services. It took its data from a twice-yearly survey of adult injectors (and later other drug users too) in each city which began in 2007, recruiting participants via street agencies. The featured study limited itself to those who had injected in the last three months (288 in Vancouver and 291 in Victoria). Nearly 70% of participants were men and they averaged 40 years of age. Over 70% of in both cities said they were homeless or unstably housed.

Main findings

Despite some demographic differences, in both cities about two thirds of survey respondents were daily injectors. However, in Victoria the odds of them having shared versus not shared a needle in the past 12 months were two to three times higher after other factors had been taken in to account. Of greatest interest was how sharing varied before and after closure of the needle exchange centre. Though not statistically significant, in Victoria the proportion having shared rose from 9.5% in early 2008 just before the closure to 20% in late 2010, while in Vancouver the proportion remained relatively steady at under 10%.

Another finding was that people who had injected crack or oxycodone in the previous month were much more likely than other injectors to have sharing needles in the past 12 months.

After the closure in Victoria participants were asked how this had affected them and what changes they had noticed. Many but not all talked of difficulty getting clean needles or of sharing needles more often.

The authors' conclusions

This study confirms the contribution to public health made by needle and syringe distribution programmes by reducing injecting-related risk behaviours such as needle sharing and re-use. It draws attention to the substantial and persistent problems associated with injecting drug use in Victoria following closure of the fixed-site needle and syringe distribution centre. The increase there in needle sharing from under 10% in early 2008 to 20% in late 2010 is troubling. Accounts of injectors raise concerns about difficulties accessing clean needles and a tendency to be more likely to share needles. Furthermore, the most recent national Canadian study tracking infection risk behaviour among injectors found that 23% (up from 19% in 2006) of participants in Victoria reported sharing needles, while 22% who knew they were infected with hepatitis C still passed their used needles to others.

It should be acknowledged that these results derive non-random samples of injectors and may have been influenced by changes in the samples at different time points. A study like this can only produce findings consistent with a causal relationships between the needle and syringe distribution centre's closure and trends in injecting drug use, not prove there was such a relationship.


Findings logo commentary This study took advantage of a 'natural experiment' which threw in to relief the value of an accessible and well staffed central location for obtaining injecting equipment and allied advice and care. Mobile services reach people not reached by a fixed centre, but a centre offers a hub at a known location and known times, and a place to stay and talk and receive other services.

The implications are at least twofold: first that such services are very vulnerable, occupying a narrow tolerance zone almost at and often beyond the edge of public acceptability; and secondly, that accessibility is the key to getting enough infection-free equipment to injectors to prevent the spread of infection. These two considerations came in to conflict in Victoria.

It was a small study whose findings cannot securely establish the consequences of the closure, partly for the reasons given by the authors, but also because from their own account drug use patterns were changing in Victoria (the increase in crack injecting) in ways which might have affected the sharing of injecting equipment regardless of the closure. Nevertheless the study is valuable because 'intentional experiments' randomly allocating areas or people to have or not have needle exchange services are extremely rare.

To interpret the findings it is essential to know what was lost – not an hour or two a day office-hours service, but a comprehensive extended hours operation. As described in another report on the closure, the centre was open seven days a week from 3pm to 11pm, staffed among others by 'street nurses' who offered health services and referrals. The centre also offered a range of welfare services. Closure of the needle exchange was forced by the landlord in response to complaints from neighbours about open street drug use, loitering and garbage. Attempts were made to compensate with mobile and outreach services, but pressure from neighbourhood groups also led to the banning of any needle exchange services in the vicinity of the centre, injectors found it hard to remember where mobile services were and when or could not get to them at those times, and the nature of these services was that contact was fleeting with no space for confidential counselling and private medical care. A "safe haven from the street that provided a trusted point of access to services" had gone. The number of needles distributed plummeted by 40% and the number of clients served fell by over a quarter. The ease and convenience balance was tipped between obtaining fresh injecting equipment versus used equipment more immediately available from another injector. Ironically, a closure intended to prevent drug-related nuisance led to more nuisance (loitering and disturbances) in neighbouring areas. Resistance to reopening a fixed site service elsewhere left this gap for at least three years.

For more on needle exchange generally and in Britain in particular see this recent Findings analysis. For other city-based case studies of the impact of the availability and non-availability of needle exchange services see this Findings review, one of a series of four on needle exchange and hepatitis C.

Last revised 27 October 2012. First uploaded 27 October 2012

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