Cost-effectiveness of combined sexual and
injection risk reduction interventions among
Female Sex Workers who inject drugs in two
very distinct Mexican-US border cities
José L. Burgos, MD, MPH, AAHIVS
Assistant Professor
Division of Global Public Health School of Medicine
University of California San Diego
Funding: NIMH grant # K01 MH095680
NIDA grant # R01 DA023877
NIDA grant # R01 DA023877-S1
NIMH grant #R01 MH065849
Coauthors/Co-Investigators
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Jose Luis Burgos, UC San Diego, USA
Thomas L. Patterson, UC San Diego, USA
Joshua S. Graff-Zivin, UC San Diego, USA
James G. Kahn, UC San Francisco, USA
Gudelia Rangel, COLEF, Mx.
Victoria D. Ojeda, UC San Diego, USA
M. Remedios Lozada, ISESALUD, Mx.
Hugo Staines, UACJ, Mx.
Steffanie A. Strathdee, UC San Diego, USA
Clinical trial registration number: NCT00840658
About Mujer Mas Segura
• A brief combined theory-based intervention to
simultaneously reduce sexual and injection
risks among IDU-FSWs ages 18+
• IDU-FSWs from Tijuana and Cd. Juarez were
randomized to simultaneously examine two
interventions
– Interactive Vs. Lecture formats
• Measures: questionnaires; biological samples
to detect four STIs including HIV
http://gph.ucsd.edu/research/contaminacion.shtml
2x2
Intervention
Factorialeffects
Designon
to HIV/STI
Simultaneously
incidence
Evaluate
after 12 Injection
months:
and Sexual Risk
Reduction
Cd.
Tijuana
Juarez Intervention
No
Yes
Risk intervention
Interactive Sex
Interactive Injection Risk Intervention (Adj RR; 95% CI*)
No
Yes
Group A (control)
Group B
1.15
Reference
Group C
0.38
0.44
(0.16, 0.99)
0.89)
(0.19,
(0.58, 2.28)
Group D
0.37
1.12
(0.16,
(0.56, 0.89)
2.25)
*Adjusted for # of unprotected sex acts with non-regular clients , and arrests prior to enrolment
Strathdee, et al. 2012
Impact of Injection Risk Interventions on
Injection Risk Index: Tijuana and Cd. Juarez
Strathdee, et al. 2012
Goal of the CE analysis
• To assess the cost-effectiveness of a behavioral
intervention combining two interventions to
increase safer sex and safer injection practices
among FSW-IDUs in Ciudad Juarez and Tijuana,
Mexico.
• To inform evidenced based Sex work-harm
reduction policies in the Mexico-U.S. border
region in respect to access to sterile syringes and
condoms among FSW-IDUs.
Cost Effectiveness Model
• Discrete transitional state mathematical model
• Costs and outcomes for one-year and remainder
of life of FSW-IDUs comparing a lecture format to
each individual interactive components and the
combined MMS intervention.
• Societal perspective
• Multivariate sensitivity analysis
• Cost and outcomes discounted at an annual rate
of 3%
• Currency adjusted to 2012 U.S. Dollars
Model Inputs
Costs
Administrative personnela
Outreach workersa
Counseling session (30 min)
RN sample collection (15 min)
Gc/CT
RPR
Rapid HIV test
HIV confirmatory test
Syringes, gloves, speculum, other
Chlamydia (Azitrhromycin 1 gr.)
Gc (Ceftriaxone 125 mg)
Syphilis (Benzathine penicillin G)
Three doses for HIV positive FSWs
Participant’s time (hour)
Space/Utilities/mileagea
aAnnual
Base Value
$9,000
$9,600
$6.00
$3.00
$22.00
$5.00
$5.00
$56.00
$2.00
$20.00
$12.70
$ 10.00
$30.00
$6.29
$7,900
Source
STPSb, CONASAMIc
STPSb, ISESALUDd
STPSb, ISESALUDd
STPSb, ISESALUDd
MMSe, CANf
MMSe, SEg
MMSe, SEg
MMSe, SEg
MMSe, SEg
MMSe, SEg
MMSe, SEg
MMSe, SEg
MMSe, SEg
STPSb, CONASAMIc
MMSe
costs; bSecretaría del Trabajo y Previsión Social ; cComisión Nacional de Salarios Mínimos; dInstituto de Servicios de Salud Pública; eMujer Mas Segura Project; fSecretaría de Economía
Base
value
Range
Among FSW-IDUs in Tijuanaa
64.3
(34.6, 93.9)
Among FSW-IDUs in Cd. Juareza
66.1
(30.2, 102.0)
Model Inputs
HIV/STI combined incidence:
Calculated HIV injection risk:
Receptive contaminated syringe sharinga
0.669
Shared contaminated cotton/cooker/watera
0.0067
Contaminated syringe cleaned with bleacha
0
(0, 0.21)
0.005
7.5
(0.003, 0.089)
(6, 11)
Utilities
QALYb lost per STI episode
QALYb lost due to HIV infection
aPer
100 person years
adjusted life years
bQuality
Cost-Effectiveness on
Averted STI
Strategy
Control sex groups
(Lecture format)
Intervention sex groups
(Interactive format)
Cost per averted episode of
sexually transmitted infection
Tijuana
Cd. Juarez
--
--
$42
$41
Reported Episodes of Receptive Syringe Sharing
During the Previous Month
Control injection group
Intervention Injection group
81
79
52
15
Baseline
21
16
12 months
Tijuana
55
Baseline
16
12 months
Ciudad Juarez
Cost-Effectiveness on
Safer Injection Practices
Strategy
Control injection groups
(Lecture format)
Intervention Injection groups
(Interactive format)
Cost per averted episode of
receptive syringe sharing
Tijuana
Cd. Juarez
--
--
--
$5.00
Base case results for a cohort of 1,000 FSW-IDUs
over a life-time
Strategy
Didactic control
Interactive Safe Sex/ Lecture
format Safe Injection
Interactive Safe Injection/
Lecture format Safe Sex
Combined interactive Safe
Sex/Interactive Safe Injection
Cost-Effectivenessa
Tijuana
Cd. Juarez
--
--
$5,921
$4,710
Dominated
Dominated
$94,166,643
$7,162.74
aCost
per QALY gained
180000
160000
Reported Numbers of Syringes Exchanged and
Prevenkits* Distributed in Tijuana and Cd. Juarez
2007-2011
140000
120000
100000
Cd. Juarez Syringes
80000
Cd. Juarez Prevenkits
60000
Tijuana Syringes
40000
Tijuana Prevenkits
20000
*kits with sterile water,
cooker, cotton & syringes
0
Year
2007
2008
2009
2010
Study Period
2011
Tijuana– Multivariate Cost-Effectiveness Analysis
Interactive safer sex/
Interactive format safe sex intervention/
Lecture
injection
Lecture formasafer
safe injection
intervention
Cd. Juarez– Multivariate Cost-Effectiveness Analysis
For ciudad Juarez – Multivariate analysis
Interactive safer sex/
Lecture safer injection
Conclusions
• In the absence of expanded NEP the
combined Mujer Mas Segura intervention
is likely to be cost-effective
• Improved access to sterile injection
equipment at the community level shows a
larger impact in reducing unsafe injection
practices among FSW-IDU, with no
significant added benefit from the
interactive safer-injection component of
the Mujer Mas Segura Intervention.
Acknowledgements
• Our participants and the sex worker
communities in Tijuana and Cd. Juarez
• NIH Grants: R01 DA023877
DA023877-S1
K01 MH095680
• Staff from the Preven Casa, A. C., UCSD
• San Diego County Public Health Laboratory
References
•
Patterson TL, Mausbach B, Lozada R, Staines-Orozco H, Semple SJ, Fraga-Vallejo
M, Orozovich P, Abramovitz DA, de la Torre A, Amaro H, Martinez G, MagisRodriguez C, Strathdee SA. Efficacy of a brief behavioral intervention to
promote condom use among female sex workers in Tijuana and Ciudad Juarez,
Mexico. Am J Public Health. 2008;98(11):2051-2057.
•
Burgos JL, Gaebler JA, Strathdee SA, Lozada R, Staines H, Patterson TL: Costeffectiveness of an intervention to reduce HIV/STI incidence and promote
condom use among female sex workers in the Mexico-US border region. PLOS
One 2010, 5(6):e11413.
•
Strathdee SA, Magis-Rodriguez C: Mexico's evolving HIV epidemic. JAMA 2008,
300(5):571-573.
•
Bell DC, Trevino RA: Modeling HIV risk. J Acquir Immune Defic Syndr 1999,
22(3):280-287.
•
Sonnenberg FA, Beck JR: MARKOV-MODELS IN MEDICAL DECISION-MAKING A PRACTICAL GUIDE. Medical Decision Making 1993, 13(4):322-338.
Extra Slides
Prop. OR for reported easy access to sterile syringes