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U.S. Department
of Health and Human Services Contents
4. Cost-Effectiveness of Needle
Exchange Programs Holtgrave DR, Pinkerton SD, Jones
TS, Lurie P, Vlahov D. (1998). Cost
and cost- effectiveness of increasing access to sterile syringes and
needles as an HIV prevention intervention in the United States.
J Acquir Immune Defic
Syndr Hum Retrovirol 1998;
18 Suppl 1:S133-8. ABSTRACT
Summary: We determined the cost of increasing access of injection
drug users (IDUs) to sterile syringes and needles as an HIV prevention
intervention in the United States and the cost per HIV infection averted
by such a program. We considered a hypothetical cohort of 1 million
active IDUs in the United States. Standard methods were used to estimate
the cost and cost-effectiveness of policies to increase access to
sterile syringes and syringe disposal at various levels of coverage
(e.g. a 100% coverage level would ensure access to a sterile syringe for
each injection given current levels of illicit drug injection in the
United States; a 50% coverage level would ensure access to one half of
the required syringes). A mathematical model of HIV transmission was
employed to link programmatic coverage levels with estimates of numbers
of HIV infections averted. A policy of funding syringe, exchange
programs, pharmacy sales, and syringe disposal to cover all illicit drug
injections would cost just over $423 million (U.S.) for 1 year. One
third of these costs would be paid for as out-of-pocket expenditures by
IDUs purchasing syringes in pharmacies. Compared with the status quo,
this policy would cost an estimated $34,278 (U.S.) per HIV infection
averted, a figure well under the estimated lifetime costs of medical
care for a person with HIV infection. At very high levels of coverage
(>88%), the marginal cost-effectiveness of increased program coverage
becomes less favorable. Although the total costs of funding large-scale
IDU access to sterile syringes and disposal seem high, the economic
benefits are substantial. Even at high levels of coverage, such finding
would save society money. As part of a comprehensive program of HIV
prevention, policies to increase IDUs access to sterile syringes
urgently need further consideration by public health decision makers. COMMENT The estimates provided in this study should be considered in the context
of an estimated $108,469 lifetime medical cost of treating an individual
with HIV infection, which is three fold greater than estimates of
preventing one HIV infection. Kahn J. Economic Evaluation of Primary HIV Prevention in Injection Drug
Users. In Holtgrave D., edit: Handbook of Economic Evaluation HIV
Prevention Programs. Plenum Press, New York: 1998. NO PUBLISHED ABSTRACT
In this paper, the author implemented the Yale Circulation Model using
empirical data obtained from 4 NEP programs in 4 Cities to assess the
cost-effectiveness of such an HIV prevention intervention. The Yale
Circulation Model is a mathematical model used to estimate the change in
the number of new HIV infections based on lowering the HIV prevalence in
used needles as a result of reducing the circulation time of
contaminated syringes. The author applied a simplified Yale Needle
Circulation Model to 4 hypothetical needle exchange programs in areas
with differing HIV prevalence and incidence rates. The researcher
reports that reductions in HIV incidence rates varied across cities from
17% to 70% across the 4 hypothetical settings. Higher reductions were
associated with more needles per client-year. Greater efficiency was
associated with low cost per needle exchanged. The estimated cost
savings per HIV infection averted ranged from $12,000 to $99,000.
Greater efficiency was associated with low cost per needle exchanged.
The author suggests that for a fixed number of needles, the absolute
impact is higher when the needles are spread out among a greater number
of clients. COMMENT This study shows that variations in the cost-effectiveness of syringe
exchange programs will occur, depending on the type and structure of the
program, and the HIV prevalence and incidence in the geographic area to
be served. 5. Risk Associated with Closing a
Needle Exchange Program Broadhead R, Van Hulst Y, and
Heckathorn D. (In Press). Termination
of an established needle exchange: A study of claims and their impact.
Social Problems, 1999; Vol. 46,No.l: 48-66. NO PUBLISHED ABSTRACT This study assessed the impact of the Windham CT needle exchange program closure on risk behaviors, and discarded syringes. The project conducted 330 initial and 173 follow-up risk assessment interviews of NEP participants between 1994 and 1997 while the NEP was in operation. Following the closure of the NEP in 1997, researchers conducted 111 interviews at 11 months post closure and 78 interviews 3 months later. In addition, starting 7 months prior to the closure of the NEP and for a period of 1 and _ years following the NEP closure the research team surveyed public outdoor areas for discarded syringes where high levels of drug use occurred. Findings indicate that while the NEP was in operation, 14% of the sample reported obtaining syringes from unsafe sources compared with 36% following the closure of the NEP. Prior to the closure of the NEP, the mean number of times a syringe was re-used before disposal was 3.52 compared with a high of 8.18 times following the NEP closure. The closure of the NEP was also found to increase self-reported syringe sharing. Sixteen percent of NEP participants reported sharing a syringe within the last 30 days while the NEP was in operation compared with 34% of participants after the NEP closed. Finally, no difference in the number of discarded syringes in public places was detected, suggesting that the closure of the NEP had no effect on the number of discarded syringes in the area. COMMENT This
study documented the experience of IDUs in one community following
closure of a NEP. Risk behaviors increased among IDUs when they no
longer had access to the services of the needle exchange program,
increasing the likelihood of HIV transmission resulting from multiperson
reuse of syringes. Related Article by Same Authors: Broadhead
RS, van Hulst Y, Heckathorn, DD. The Impact of a Needle
Exchange's Closure. Public Health Reports 1999; 114: 439-447. 6. Needle Exchange Related Issues Junge B, Vlahov D, Riley E,
Huettner S, Brown M, Beilenson P. Pharmacy
access to sterile syringes for injection drug users: attitudes of
participants in a syringe exchange program.
J Am Pharm Assoc (Wash) 1999 Jan-Feb;39(l):17-22. ABSTRACT
Objective: To examine
attitudes of participants of a van-based syringe exchange program (SEP)
toward the hypothetical prospect of pharmacy-based syringe access.
Design: Onetime, cross-sectional survey. Setting: Baltimore, Maryland.
Participants: 206 injection drug users who participate in the Baltimore
SEP. Interventions: Face-to-face interviews. Main Outcome Measures:
Location preferred for obtaining syringes, drug and syringe use, past
experience with pharmacies, and willingness to pay. Results: The sample
was 67% men, 95% African American, and 95% unemployed; mean age was 39.8
years. A total of 19% of respondents had bought syringes at a pharmacy
during the prior six months. Some 37% reported having been turned down
when asking for syringes at a pharmacy, most commonly due to lack of
identification to prove diabetic status (50%). If legal restrictions
were lifted, 92% of respondents would obtain syringes from pharmacies,
and would be willing to pay a mean price of $0.80 (median = $1.00) per
syringe. Women were more likely than men to report the intention to
switch from van-based SEP to pharmacy (57% versus 38%, p = 0.045).
Conclusion: If current legal restrictions were lifted, pharmacies would
be a viable syringe source appealing particularly to women, suggesting
gender-specific access issues that should be addressed. The per syringe
price that study participants would be wiling to pay exceeds typical
retail prices, suggesting that pharmacists could charge enough per
syringe to recoup operational costs. COMMENT This study reflects a willingness and effort to obtain sterile injection
equipment at pharmacies by a substantial percentage of IDUs currently
using a van-based syringe exchange program. It highlights the impact of
legal restrictions on syringe availability through pharmacies for the
IDU population. The study notes that pharmacies provide an alternative
controlled distribution mechanism of sterile injection equipment and are
widely available in most communities. Paone D, Cooper H, Alperen J et
al. HIV Risk Behaviors of
Current Sex Workers Attending Syringe Exchange: The Experiences of Women
in five US Cities. AIDS
CARE 1999; 11 (3): 269-280. ABSTRACT
Existing research indicates
that sex workers who inject drugs are vulnerable to HIV infection
through both risky sexual and drug use practices. This study is the
first attempt to learn whether this increased risk persists among
current sex workers who participate in syringe exchange programmes
(SEPs). With data from interviews with randomly selected participants in
five US cities, we compared the demographic characteristics, sexual risk
behaviours, drug use practices, emotional and physical health, and SEP
utilization patterns of currently active female sex workers who attend
SEPs with female SEP participants who do not engage in sex work. Data
indicate that women enrolled in SEPs who were currently trading sex
typically reported greater HIV risk than women non-sex workers. Current
sex workers reported higher levels of risk for every drug risk variable
examined in bivariate analysis. They were more likely than other women
to inject with a syringe previously used by someone else, to inject
daily and to attend shooting galleries; they were less likely to use a
condom with their primary partners and to report higher levels of
psychological distress than their counterparts. The relationship between
sex work status and risky injection practices persisted when potential
confounders were controlled for in multivariate analysis. SEPs can serve
a pivotal role in providing sex workers with services and referrals
which would help them reduce risk behaviours. COMMENT This
study documents that women who attend SEPs and engage in sex work
typically report greater HIV risk than women non-sex workers attending
SEPs, reinforcing the importance of this variable. In this study,
current sex workers engaged in heavier drug use than other women;
reported using a greater variety of injection and non-injection drugs;
injected substantially more frequently than both sexually active and
non-sexually active women, with sex workers injecting on average 124
times a month while other women injected approximately 82 times a month
(p<0.0005); were more likely to inject daily and smoke crack daily
than their counterparts; and were more likely to be at risk of
bloodborne infection through risky injection practices such as renting,
buying or borrowing used syringes for injection and visiting a shooting
gallery more often than other women. Riley E, Beilenson P, Vlahov D,
Smith L, Koenig M et al. Operation
Red Box: a pilot project of needle and syringe drop boxes for injection
drug users in East Baltimore. J Acquir Immune Defic Syndr Hum
Retrovirol 1998;18 Suppl 1:S120-5. ABSTRACT
Summary:
We assessed the acceptability and the use of a community-based needle
and syringe disposal project designed to serve injection drug users. In
June 1996, three surplus U.S. mail collection boxes were painted red and
used as syringe and needle drop boxes in COMMENT This paper addresses the important issue of safe disposal of used
injection equipment. While the study design is not directly linked with
a syringe exchange program, the issues of access to, and safe disposal
of, used syringes are important to consider as components of an overall
public health and safety effort. The drop boxes were placed in high drug
use areas of Baltimore, which has existing NEPs. The 11% HIV antibody
positivity rate in discarded syringes highlights the role that safe
disposal mechanisms can play in reducing the circulation time of
infected needles, regardless of the presence or absence of a syringe
exchange program. 7. Needle Exchange and Hepatitis B
and C Viruses Hagan H, McGough JP, Thiede H,
Weiss N, Hopkins S, Russell A.
Syringe exchange and risk of infection with hepatitis B and C
viruses. American Journal of Epidemiology, (1999).149,
203-213. ABSTRACT
The authors utilized a cohort
study among Seattle injection drug users (IDUs) to assess whether
participation in a syringe exchange program was associated with
incidence of hepatitis B virus (HBV) and hepatitis C virus(HCV)
infection. Susceptible IDU subjects (187 seronegative for antibody to
HCV, and 460 seronegative for core antibody to HBV) were identified in
drug treatment, corrections, and social service agencies from June 1994
to January 1996, and followed for seroconversion one year later. The
subjects included in the analysis were Seattle-King county (Washington
State) area IDUs enrolled in a larger multipurpose cohort study, the
Risk Activity Variables, Epidemiology, and Network Study (RAVEN Study).
There were 39 HCV infections (20.9/100/year) and 46 HBV infections
(10.0/100/year). There was no apparent protective effect of syringe
exchange against HBV (former exchange users, relative risk (RR) = 0.68,
95% confidence interval (CI) 0.2-2.5; sporadic exchange users, RR = 2.4,
95% CI 0.9-6.5; regular users, RR = 1.81, 95% CI 0.7-4.8; vs. RR = 1.0
for nonusers of the exchange; adjusted for daily drug injection).
Neither did the exchange protect against HCV infection (sporadic users,
RR = 2.6, 95% CI 0.8-8.5; regular users, RR = 1.3, 95% CI 0.8-2.2; vs.
RR = 1.0 for nonusers; adjusted for recent onset of injection and
syringe sharing prior to enrollment). While it is possible that
uncontrolled confounding or other bias obscured a true beneficial impact
of exchange use, these data suggest that no such benefit occur-red
during the period of the study. COMMENT: Seattle
is an area with a high HCV prevalence (70%-80%) and low HIV prevalence
(5%) among the IDU population. The probability that an IDU was an HCV
carrier was greater than 70%; and given the efficiency of HCV
transmission, any syringe sharing or sharing of other injection
equipment (e.g., cooker, rinse water, cotton) increases the risk for HCV
infection. During the period in which HBV/HCV was studied in this
cohort, the incidence of HIV infection was quite low, with only 4
seroconversions (0.2%) among 1651 study participants. A high incidence
of viral hepatitis can occur in the presence of low HIV incidence,
presumably related to higher prevalence of HCV/HBV carriers as well as
the greater infectiousness and higher per contact risk of acquiring HBV
than HIV. 8. Needle Exchange Programs in
Vancouver: An Update on Needle Exchange Programs and HIV Incidence Schechter M, Strathdee S, Cornelisse PGA et al. Do needle exchange programs increase the spread of HIV among injection drug users: An investigation of the Vancouver outbreak. AIDS 1999 Apr 16;13(6):F45-51. ABSTRACT Objective: An association between needle exchange attendance and higher HIV prevalence rates among injecting drug users (IDU) in Vancouver has been interpreted by some to suggest that needle exchange programmes (NEP) may exacerbate HIV spread. We investigated this observed association to determine whether needle exchange was causally associated with the spread of HIV. Design and Method: Prospective cohort study of 694 IDU recruited in the downtown eastside of Vancouver. Subjects were HIV-negative at the time of recruitment and had injected illicit drugs within the previous month. Results: Of 694 subjects, the 15-month cumulative HIV incidence was significantly elevated in frequent NEP attendees (11.8+ 1.7 versus 6.2 + 1.5%; log-rank P = 0.012). Frequent attendees (one or more visits per week) were younger and were more likely to report: unstable housing and hotel living, the downtown eastside as their primary injecting site, frequent cocaine injection, sex trade involvement, injecting in ‘shooting galleries’, and incarceration within the previous 6 months. The Cox regression model predicted 48 seroconversions among frequent attendees; 47 were observed. Although significant proportions of subjects reported obtaining needles, swabs, water and bleach from the NEP, only five (0.7%) reported meeting new friends or people there. When asked where subjects had met their new sharing partners, only one out of 498 respondents cited the needle exchange. Paired analysis of risk variables at baseline and the first follow-up visit did not reveal any increase in risk behaviours among frequent attendees, regardless of whether they had initiated drug injection after establishment of the NEP. Conclusions: We found no evidence that this NEP is causally associated with HIV transmission. The observed association should not be cited as evidence that NEPs may promote the spread of HIV. By attracting higher risk users, NEPs may furnish a valuable opportunity to provide additional preventive/support services to these difficult-to-reach individuals. COMMENT This report from the Vancouver Injection Drug User Study documents the severity of drug use, high risk behaviors and lifestyle characteristics of frequent attenders of the Vancouver needle exchange program compared with infrequent attenders of the program. There was no evidence that the NEP promoted new needle sharing network formation, and no evidence of increased risk behaviors related to injection practices. Significant variables distinguishing the frequent attenders from infrequent attenders (at p< 0.001 level) included unstable housing, living in a hotel, injecting in shooting galleries, frequency of heroin and cocaine use, incarceration in the past 6 months, involvement in the sex trade, and other sources of illegal income. The impact of these differences must be noted, and two statistical models were used to assess the impact of these higher risk characteristics on expected new HIV seroconversions. A multivariate Cox regression model containing these variables yielded a good fit with the actual observation of new seroconversions in both frequent attenders (48 predicted, 47 observed) and among infrequent attenders (18 seroconversions predicted, 17 observed). A second analysis was conducted using a logistic regression model, with predicted seroconversion rates of 45 among frequent attenders and 19 among infrequent attenders - fairly close to the 47 observed in frequent attenders and 17 observed in infrequent attenders, respectively. This suggests that these risk factors themselves are more predictive of HIV seroconversion than patterns of SEP attendance. A more comprehensive approach to addressing the needs of the IDU may be required, in addition to the availability of sterile injection equipment, to achieve effective HIV prevention in this highest risk population. 9. SUMMARY POINTS From Updated Syringe Exchange Literature • Laboratory studies show prolonged viability of HIV in used needles (> 4 weeks), providing strong biologic rationale for removal of used drug injection equipment from circulation. • Syringe exchange programs (SEPs) consistently attract persons with highest risk profiles for HIV infection and severe drug use, and are successful in referring SEP clients into detoxification and substance abuse treatment programs. • SEP-referred clients have similar rates of retention in substance abuse treatment as individuals from standard referral sources, despite more severe baseline drug use and high-risk lifestyles. • Clients participating in SEPs have decreased reuse of contaminated syringes and reduced sharing of injection equipment. • The data indicate that the presence of a syringe exchange program does not increase the use of illegal drugs among participants, and in many cases, a decrease in injection frequency has been observed among those attending these programs. • Provision of sterile injection equipment through SEPs and pharmacy access is cost-effective; one HIV infection can be prevented for one third the cost of medical care for an infected person. • The scientific evidence accumulated to date provides a basis on which municipalities that are heavily affected by an HIV epidemic driven by injection drug use should consider syringe exchange programs as a tool for the identification, referral and retention of active users of injection drugs into these services, as part of a comprehensive HIV prevention plan. Back to part 1 of the annotated bibliography. Review by the Surgeon General Statement from Congresswoman Nancy Pelosi releasing the Surgeon General's review, April 13, 2000. Letter from Secretary of Health and Human Services Donna E. Shalala submitting the Surgeon General's review to Congresswoman Nancy Pelosi.
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