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Donnadieu H, Quillet C, D’Ottavi M, Castellani J, Debellefontaine A, Guichard S, Baglioni R, Langendorfer N, Faucherre V, Hanslik B, Tuaillon E, Laureillard D, Nagot N. Community-based respondent-driven sampling as a strategy for drug use surveillance in a large French urban area. Harm Reduct J 2023; 20:82. [PMID: 37386636 PMCID: PMC10308670 DOI: 10.1186/s12954-023-00814-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/16/2023] [Indexed: 07/01/2023] Open
Abstract
BACKGROUND Understanding drug use and behavior within the PWUD population is crucial to adapt harm reduction and prevention strategies, and provide improved addiction and medical treatment. However, in most countries such as France, the knowledge of drug use behaviors is likely biased as it originates from addiction centers which are attended by only an unknown proportion of PWUD. The objectives of this study were to describe drug use behavior in a population of active PWUD in the urban area of Montpellier, South of France. METHODS We implemented a community-based respondent-driven sampling survey (RDSS), a validated strategy to obtain a representative sample of a population, to recruit PWUD in the city. Adult individuals reporting frequent psychoactive drug use other than cannabis, with confirmation by urine test, were eligible. Beside HCV and HIV testing, trained peers interviewed participants on their drug consumption and behavior using standardized questionnaires. Fifteen seeds launched the RDSS. RESULTS During the 11 weeks of the RDSS, 554 actives PWUD were consecutively included. They were mostly men (78.8%), had a median age of 39 years, and only 25.6% had a stable living place. On average, participants consumed 4.7 (± 3.1) different drugs, and 42.6% smoked free-base cocaine. Unexpectedly, heroin and methamphetamine were consumed by 46.8% and 21.5% of participants, respectively. Among the 194 participants injecting drugs, 33% declared sharing their equipment. CONCLUSION This RDSS highlighted a high consumption of heroin, crack and methamphetamine in this PWUD population. These unexpected results can be explained by low attendance to addiction centers, the source of drug use reports. Despite free care and risk reduction equipment in the city, sharing was very frequent among injectors, challenging the current program of harm reduction.
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Affiliation(s)
- Hélène Donnadieu
- Department of Addiction Medicine, Montpellier University Hospital, 80 Rue Augustin Fliche, 34090 Montpellier, France
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
| | - Catherine Quillet
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
| | - Morgana D’Ottavi
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
| | - Joëlle Castellani
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
| | - Anne Debellefontaine
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
- AXESS, Harm Reduction Center, SOS Solidarités, 66 Avenue Charles Flahaut, 34090 Montpellier, France
| | - Sylvain Guichard
- Association of Marginality and Drug Addiction (AMT), 10 Boulevard Victor Hugo, 34000 Montpellier, France
| | - René Baglioni
- Department of Addiction Medicine, Montpellier University Hospital, 80 Rue Augustin Fliche, 34090 Montpellier, France
| | - Nicolas Langendorfer
- Department of Addiction Medicine, Montpellier University Hospital, 80 Rue Augustin Fliche, 34090 Montpellier, France
| | - Vincent Faucherre
- Department of Addiction Medicine, Montpellier University Hospital, 80 Rue Augustin Fliche, 34090 Montpellier, France
| | - Bertrand Hanslik
- Department of Addiction Medicine, Montpellier University Hospital, 80 Rue Augustin Fliche, 34090 Montpellier, France
| | - Edouard Tuaillon
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
| | - Didier Laureillard
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
- Department of Infectious Diseases, Caremeau University Hospital, Place du Professeur Robert Debré, 30029 Nîmes, France
| | - Nicolas Nagot
- Pathogenesis and Control of Chronic and Emerging Infections, Etablissement Français du Sang, INSERM, University of Antilles-Guyane, University of Montpellier, 60 Rue de Navacelles, 34394 Montpellier, France
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Sweeney S, Ward Z, Platt L, Guinness L, Hickman M, Hope V, Maher L, Iversen J, Hutchinson SJ, Smith J, Ayres R, Hainey I, Vickerman P. Evaluating the cost-effectiveness of existing needle and syringe programmes in preventing hepatitis C transmission in people who inject drugs. Addiction 2019; 114:560-570. [PMID: 30674091 DOI: 10.1111/add.14519] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 07/06/2018] [Accepted: 11/26/2018] [Indexed: 12/12/2022]
Abstract
AIM To evaluate the cost-effectiveness of needle and syringe programmes (NSPs) compared with no NSPs on hepatitis C virus (HCV) transmission in the United Kingdom. DESIGN Cost-effectiveness analysis from a National Health Service (NHS)/health-provider perspective, utilizing a dynamic transmission model of HCV infection and disease progression, calibrated using city-specific surveillance and survey data, and primary data collection on NSP costs. The effectiveness of NSPs preventing HCV acquisition was based on empirical evidence. SETTING AND PARTICIPANTS UK settings with different chronic HCV prevalence among people who inject drugs (PWID): Dundee (26%), Walsall (18%) and Bristol (45%) INTERVENTIONS: Current NSP provision is compared with a counterfactual scenario where NSPs are removed for 10 years and then returned to existing levels with effects collected for 40 years. MEASUREMENTS HCV infections and cost per quality-adjusted life year (QALY) gained through NSPs over 50 years. FINDINGS Compared with a willingness-to-pay threshold of £20 000 per QALY gained, NSPs were highly cost-effective over a time-horizon of 50 years and decreased the number of HCV incident infections. The mean incremental cost-effectiveness ratio was cost-saving in Dundee and Bristol, and £596 per QALY gained in Walsall, with 78, 46 and 40% of simulations being cost-saving in each city, respectively, with differences driven by coverage of NSP and HCV prevalence (lowest in Walsall). More than 90% of simulations were cost-effective at the willingness-to-pay threshold. Results were robust to sensitivity analyses, including varying the time-horizon, HCV treatment cost and numbers of HCV treatments per year. CONCLUSIONS Needle and syringe programmes are a highly effective low-cost intervention to reduce hepatitis C virus transmission, and in some settings they are cost-saving. Needle and syringe programmes are likely to remain cost-effective irrespective of changes in hepatitis C virus treatment cost and scale-up.
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Affiliation(s)
- Sedona Sweeney
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Zoe Ward
- Bristol Medical School, Population Health Sciences, University of Bristol, Bristol, UK
| | - Lucy Platt
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Lorna Guinness
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Matthew Hickman
- Bristol Medical School, Population Health Sciences, University of Bristol, Bristol, UK
| | - Vivian Hope
- Public Health Institute, Liverpool John Moores University, Liverpool, UK
| | - Lisa Maher
- Kirby Institute for Infection and Immunity, UNSW, Sydney, Australia
| | - Jenny Iversen
- Kirby Institute for Infection and Immunity, UNSW, Sydney, Australia
| | | | - Josie Smith
- Public Health Wales, Cardiff, Wales, UK, CF10 4BZ
| | | | | | - Peter Vickerman
- Bristol Medical School, Population Health Sciences, University of Bristol, Bristol, UK
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3
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Stone J, Fraser H, Lim AG, Walker JG, Ward Z, MacGregor L, Trickey A, Abbott S, Strathdee SA, Abramovitz D, Maher L, Iversen J, Bruneau J, Zang G, Garfein RS, Yen YF, Azim T, Mehta SH, Milloy MJ, Hellard ME, Sacks-Davis R, Dietze PM, Aitken C, Aladashvili M, Tsertsvadze T, Mravčík V, Alary M, Roy E, Smyrnov P, Sazonova Y, Young AM, Havens JR, Hope VD, Desai M, Heinsbroek E, Hutchinson SJ, Palmateer NE, McAuley A, Platt L, Martin NK, Altice FL, Hickman M, Vickerman P. Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis. THE LANCET. INFECTIOUS DISEASES 2018; 18:1397-1409. [PMID: 30385157 PMCID: PMC6280039 DOI: 10.1016/s1473-3099(18)30469-9] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/30/2018] [Accepted: 07/12/2018] [Indexed: 01/01/2023]
Abstract
BACKGROUND People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID. METHODS In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity. FINDINGS We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40-2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28-2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94-1·65) and a 21% increase in HCV (1·21, 1·02-1·43) acquisition risk. INTERPRETATION Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID. FUNDING Engineering and Physical Sciences Research Council, National Institute for Health Research, National Institutes of Health.
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Affiliation(s)
- Jack Stone
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
| | - Hannah Fraser
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Aaron G Lim
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Josephine G Walker
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Zoe Ward
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Louis MacGregor
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Adam Trickey
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Sam Abbott
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Steffanie A Strathdee
- Division of Infectious Diseases and Global Public Health, University of California San Diego, La Jolla, CA, USA
| | - Daniela Abramovitz
- Division of Infectious Diseases and Global Public Health, University of California San Diego, La Jolla, CA, USA
| | - Lisa Maher
- Kirby Institute for Infection and Immunity, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Jenny Iversen
- Kirby Institute for Infection and Immunity, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Julie Bruneau
- Department of Family Medicine, Université de Montréal, Montréal, QC, Canada; Centre hospitalier de l'Université de Montreal, Montréal, QC, Canada
| | - Geng Zang
- Centre hospitalier de l'Université de Montreal, Montréal, QC, Canada
| | - Richard S Garfein
- Division of Infectious Diseases and Global Public Health, University of California San Diego, La Jolla, CA, USA
| | - Yung-Fen Yen
- Section of Infectious Diseases, Taipei City Hospital, Taipei City Government, Taipei, Taiwan
| | - Tasnim Azim
- James P Grant School of Public Health, BRAC University, Dhaka, Bangladesh
| | - Shruti H Mehta
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Michael-John Milloy
- BC Centre for Excellence in HIV/AIDS and Division of AIDS, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Margaret E Hellard
- Burnet Institute, Melbourne, VIC, Australia; Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Rachel Sacks-Davis
- Burnet Institute, Melbourne, VIC, Australia; Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | | | | | - Malvina Aladashvili
- Infectious Diseases, AIDS and Clinical Immunology Research Center, Tbilisi, Georgia
| | - Tengiz Tsertsvadze
- Infectious Diseases, AIDS and Clinical Immunology Research Center, Tbilisi, Georgia; Faculty of Medicine, Tbilisi State University, Tbilisi, Georgia
| | - Viktor Mravčík
- National Monitoring Centre for Drugs and Addiction, Prague, Czech Republic; Department of Addictology, The First Medical Faculty, Charles University and General University Hospital in Prague, Prague, Czech Republic; National Institute of Mental Health, Klecany, Czech Republic
| | - Michel Alary
- University Hospital Centre of Québec Research Centre-Laval University, QC, Canada; National Institute of Public Health of Québec, QC, Canada
| | - Elise Roy
- National Institute of Public Health of Québec, QC, Canada; Faculty of Medicine and Health Sciences, University of Sherbrooke, Longueuil, QC, Canada
| | - Pavlo Smyrnov
- International Charitable Foundation Alliance for Public Health, Kiev, Ukraine
| | - Yana Sazonova
- International Charitable Foundation Alliance for Public Health, Kiev, Ukraine
| | - April M Young
- Department of Epidemiology, University of Kentucky College of Public Health, KY, USA; Center on Drug and Alcohol Research, University of Kentucky, KY, USA
| | - Jennifer R Havens
- Center on Drug and Alcohol Research, University of Kentucky, KY, USA
| | - Vivian D Hope
- Public Health Institute, Liverpool John Moores University, Liverpool, UK; National Infection Service, Public Health England, London, UK
| | - Monica Desai
- National Infection Service, Public Health England, London, UK
| | | | - Sharon J Hutchinson
- School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, National Health Service National Services Scotland, Glasgow, UK
| | - Norah E Palmateer
- School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, National Health Service National Services Scotland, Glasgow, UK
| | - Andrew McAuley
- School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Lucy Platt
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Natasha K Martin
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK; Division of Infectious Diseases and Global Public Health, University of California San Diego, La Jolla, CA, USA
| | - Frederick L Altice
- Yale School of Medicine, Department of Medicine, Section of Infectious Diseases, AIDS Program, New Haven, CT, USA
| | - Matthew Hickman
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Peter Vickerman
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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Fraser H, Mukandavire C, Martin NK, Goldberg D, Palmateer N, Munro A, Taylor A, Hickman M, Hutchinson S, Vickerman P. Modelling the impact of a national scale-up of interventions on hepatitis C virus transmission among people who inject drugs in Scotland. Addiction 2018; 113:2118-2131. [PMID: 29781207 PMCID: PMC6250951 DOI: 10.1111/add.14267] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/02/2017] [Accepted: 05/04/2018] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND AIMS To reduce hepatitis C virus (HCV) transmission among people who inject drugs (PWID), Scottish Government-funded national strategies, launched in 2008, promoted scaling-up opioid substitution therapy (OST) and needle and syringe provision (NSP), with some increases in HCV treatment. We test whether observed decreases in HCV incidence post-2008 can be attributed to this intervention scale-up. DESIGN A dynamic HCV transmission model among PWID incorporating intervention scale-up and observed decreases in behavioural risk, calibrated to Scottish HCV prevalence and incidence data for 2008/09. SETTING Scotland, UK. PARTICIPANTS PWID. MEASUREMENTS Model projections from 2008 to 2015 were compared with data to test whether they were consistent with observed decreases in HCV incidence among PWID while incorporating the observed intervention scale-up, and to determine the impact of scaling-up interventions on incidence. FINDINGS Without fitting to epidemiological data post-2008/09, the model incorporating observed intervention scale-up agreed with observed decreases in HCV incidence among PWID between 2008 and 2015, suggesting that HCV incidence decreased by 61.3% [95% credibility interval (CrI) = 45.1-75.3%] from 14.2/100 person-years (py) (9.0-20.7) to 5.5/100 py (2.9-9.2). On average, each model fit lay within 84% (10.1/12) of the confidence bounds for the 12 incidence data points against which the model was compared. We estimate that scale-up of interventions (OST + NSP + HCV treatment) and decreases in high-risk behaviour from 2008 to 2015 resulted in a 33.9% (23.8-44.6%) decrease in incidence, with the remainder [27.4% (17.6-37.0%)] explained by historical changes in OST + NSP coverage and risk pre-2008. Projections suggest that scaling-up of all interventions post-2008 averted 1492 (657-2646) infections over 7 years, with 1016 (308-1996), 404 (150-836) and 72 (27-137) due to scale-up of OST + NSP, decreases in high-risk behaviour and HCV treatment, respectively. CONCLUSIONS Most of the decline in hepatitis C virus (HCV) incidence in Scotland between 2008 and 2015 appears to be attributable to intervention scale-up (opioid substitution therapy and needle and syringe provision) due to government strategies on HCV and drugs.
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Affiliation(s)
- H Fraser
- University of Bristol, Bristol, UK
| | | | - NK Martin
- University of Bristol, Bristol, UK,University of California, San Diego, USA
| | | | | | - A Munro
- University of the West of Scotland, Paisley, UK
| | - A Taylor
- University of the West of Scotland, Paisley, UK
| | | | - S Hutchinson
- Glasgow Caledonian University, Glasgow, UK,Health Protection Scotland, Glasgow, UK
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Ward Z, Platt L, Sweeney S, Hope VD, Maher L, Hutchinson S, Palmateer N, Smith J, Craine N, Taylor A, Martin N, Ayres R, Dillon J, Hickman M, Vickerman P. Impact of current and scaled-up levels of hepatitis C prevention and treatment interventions for people who inject drugs in three UK settings-what is required to achieve the WHO's HCV elimination targets? Addiction 2018; 113:1727-1738. [PMID: 29774607 PMCID: PMC6175066 DOI: 10.1111/add.14217] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/15/2017] [Accepted: 03/05/2018] [Indexed: 12/24/2022]
Abstract
AIMS To estimate the impact of existing high-coverage needle and syringe provision (HCNSP, defined as obtaining more than one sterile needle and syringe per injection reported) and opioid substitution therapy (OST) on hepatitis C virus (HCV) transmission among people who inject drugs (PWID) in three UK settings and to determine required scale-up of interventions, including HCV treatment, needed to reach the World Health Organization (WHO) target of reducing HCV incidence by 90% by 2030. DESIGN HCV transmission modelling using UK empirical estimates for effect of OST and/or HCNSP on individual risk of HCV acquisition. SETTING AND PARTICIPANTS Three UK cities with varying chronic HCV prevalence (Bristol 45%, Dundee 26%, Walsall 19%), OST (72-81%) and HCNSP coverage (28-56%). MEASUREMENTS Relative change in new HCV infections throughout 2016-30 if current interventions were stopped. Scale-up of HCNSP, OST and HCV treatment required to achieve the WHO elimination target. FINDINGS Removing HCNSP or OST would increase the number of new HCV infections throughout 2016 to 2030 by 23-64 and 92-483%, respectively. Conversely, scaling-up these interventions to 80% coverage could achieve a 29 or 49% reduction in Bristol and Walsall, respectively, whereas Dundee may achieve a 90% decrease in incidence with current levels of intervention because of existing high levels of HCV treatment (47-58 treatments per 1000 PWID). If OST and HCNSP are scaled-up, Walsall and Bristol can achieve the same impact by treating 14 or 40 per 1000 PWID annually, respectively (currently two and nine treatments per 1000 PWID), while 18 and 43 treatments per 1000 PWID would be required if OST and HCNSP are not scaled-up. CONCLUSIONS Current opioid substitution therapy and high-coverage needle and syringe provision coverage is averting substantial hepatitis C transmission in the United Kingdom. Maintaining this coverage while getting current drug injectors onto treatment can reduce incidence by 90% by 2030.
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Affiliation(s)
- Zoe Ward
- Bristol Medical School, Population Health SciencesUniversity of BristolBristolUK
| | - Lucy Platt
- Faculty of Public Health and PolicyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Sedona Sweeney
- Faculty of Public Health and PolicyLondon School of Hygiene and Tropical MedicineLondonUK
| | - Vivian D. Hope
- Public Health EnglandUK
- Public Health Institute, Liverpool John Moores UniversityLiverpoolUK
| | - Lisa Maher
- Kirby Institute for Infection and Immunity, UNSWAustralia
| | - Sharon Hutchinson
- Health and Life SciencesGlasgow Caledonian UniversityUK
- Blood‐borne Viruses and Sexually Transmitted Infections SectionHealth Protection ScotlandUK
| | - Norah Palmateer
- Health and Life SciencesGlasgow Caledonian UniversityUK
- Blood‐borne Viruses and Sexually Transmitted Infections SectionHealth Protection ScotlandUK
| | - Josie Smith
- Substance Misuse ‐ Drugs and AlcoholPublic Health WalesUK
| | - Noel Craine
- Substance Misuse ‐ Drugs and AlcoholPublic Health WalesUK
| | - Avril Taylor
- School of Media, Society and CultureUniversity of West of ScotlandUK
| | - Natasha Martin
- Department of MedicineUniversity of California, San DiegoUSA
| | | | | | - Matthew Hickman
- Bristol Medical School, Population Health SciencesUniversity of BristolBristolUK
| | - Peter Vickerman
- Bristol Medical School, Population Health SciencesUniversity of BristolBristolUK
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6
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Fraser H, Mukandavire C, Martin NK, Hickman M, Cohen MS, Miller WC, Vickerman P. HIV treatment as prevention among people who inject drugs - a re-evaluation of the evidence. Int J Epidemiol 2018; 46:466-478. [PMID: 27524816 DOI: 10.1093/ije/dyw180] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 01/01/2023] Open
Abstract
Background Population-level associations between community measures of HIV viral load and HIV incidence have been interpreted as evidence for HIV anti-retroviral treatment (ART) as prevention among people who inject drugs (PWID). However, investigation of concurrent HCV and HIV incidence trends allows examination of alternative explanations for the fall in HIV incidence. We estimate the contribution of ART and reductions in injecting risk for reducing HIV incidence in Vancouver between 1996 and 2007. Methods A deterministic model of HIV and HCV transmission among PWID was calibrated to the baseline (1996) HIV and HCV epidemic among PWID in Vancouver. While incorporating parameter uncertainty, the model projected what levels of ART protection and decreases in injecting risk could reproduce the observed reduction in HIV and HCV incidence for 1996-2007, and so what impact would have been achieved with just ART or just reductions in injecting risk. Results Model predictions suggest the estimated reduction (84%) in HCV incidence for 1996-2007 required a 59% (2.5-97.5 percentile range 49-76%) reduction in injecting risk, which accounted for nine-tenths of the observed decrease in HIV incidence; the remainder was achieved with a moderate ART efficacy for reducing sexual HIV infectivity (70%, 51-89%) and an uncertain ART efficacy for reducing injection-related HIV infectivity (44%, 0-96%). Despite this uncertainty, projections suggest that the decrease in injecting risk reduced HIV incidence by 76% (63-85%) and ART further reduced HIV incidence by 8% (2-19%), or on its own by 3% (-34-37%). Conclusions Observed declines in HIV incidence in Vancouver between 1996 and 2007 should be seen as a success for intensive harm reduction, whereas ART probably played a small role.
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Affiliation(s)
- Hannah Fraser
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | | | - Natasha K Martin
- School of Social and Community Medicine, University of Bristol, Bristol, UK
- Division of Global Public Health, University of California San Diego, CA, USA and
| | - Matthew Hickman
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Myron S Cohen
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - William C Miller
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - Peter Vickerman
- School of Social and Community Medicine, University of Bristol, Bristol, UK
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Platt L, Sweeney S, Ward Z, Guinness L, Hickman M, Hope V, Hutchinson S, Maher L, Iversen J, Craine N, Taylor A, Munro A, Parry J, Smith J, Vickerman P. Assessing the impact and cost-effectiveness of needle and syringe provision and opioid substitution therapy on hepatitis C transmission among people who inject drugs in the UK: an analysis of pooled data sets and economic modelling. PUBLIC HEALTH RESEARCH 2017. [DOI: 10.3310/phr05050] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background
There is limited evidence of the impact of needle and syringe programmes (NSPs) and opioid substitution therapy (OST) on hepatitis C virus (HCV) incidence among people who inject drugs (PWID), nor have there been any economic evaluations.
Objective(s)
To measure (1) the impact of NSP and OST, (2) changes in the extent of provision of both interventions, and (3) costs and cost-effectiveness of NSPs on HCV infection transmission.
Design
We conducted (1) a systematic review; (2) an analysis of existing data sets, including collating costs of NSPs; and (3) a dynamic deterministic model to estimate the impact of differing OST/NSP intervention coverage levels for reducing HCV infection prevalence, incidence and disease burden, and incremental cost-effectiveness ratios to measure the cost-effectiveness of current NSP provision versus no provision.
Setting
Cost-effectiveness analysis and impact modelling in three UK sites. The pooled analysis drew on data from the UK and Australia. The review was international.
Participants
PWID.
Interventions
NSP coverage (proportion of injections covered by clean needles) and OST.
Outcome
New cases of HCV infection.
Results
The review suggested that OST reduced the risk of HCV infection acquisition by 50% [rate ratio (RR) 0.50, 95% confidence interval (CI) 0.40 to 0.63]. Weaker evidence was found in areas of high (≥ 100%) NSP coverage (RR 0.77, 95% CI 0.38 to 1.54) internationally. There was moderate evidence for combined high coverage of NSPs and OST (RR 0.29, 95% CI 0.13 to 0.65). The pooled analysis showed that combined high coverage of NSPs and OST reduced the risk of HCV infection acquisition by 29–71% compared with those on minimal harm reduction (no OST, ≤ 100% NSP coverage). NSPs are likely to be cost-effective and are cost-saving in some settings. The impact modelling suggest that removing OST (current coverage 81%) and NSPs (coverage 54%) in one site would increase HCV infection incidence by 329% [95% credible interval (CrI) 110% to 953%] in 2031 and at least double (132% increase; 95% CrI 51% to 306%) the number of new infections over 15 years. Increasing NSP coverage to 80% has the largest impact in the site with the lowest current NSP coverage (35%), resulting in a 27% (95% CrI 7% to 43%) decrease in new infections and 41% (95% CrI 11% to 72%) decrease in incidence by 2031 compared with 2016. Addressing homelessness and reducing the harm associated with the injection of crack cocaine could avert approximately 60% of HCV infections over the next 15 years.
Limitations
Findings are limited by the misclassification of NSP coverage and the simplified intervention definition that fails to capture the integrated services that address other social and health needs as part of this.
Conclusions
There is moderate evidence of the effectiveness of OST and NSPs, especially in combination, on HCV infection acquisition risk. Policies to ensure that NSPs can be accessed alongside OST are needed. NSPs are cost-saving in some sites and cost-effective in others. NSPs and OST are likely to prevent considerable rates of HCV infection in the UK. Increasing NSP coverage will have most impact in settings with low coverage. Scaling up other interventions such as HCV infection treatment are needed to decrease epidemics to low levels in higher prevalence settings.
Future work
To understand the mechanisms through which NSPs and OST achieve their effect and the optimum contexts to support implementation.
Funding
The National Institute for Health Research Public Health Research programme.
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Affiliation(s)
- Lucy Platt
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Sedona Sweeney
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Zoe Ward
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Lorna Guinness
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Matthew Hickman
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Vivian Hope
- Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK
| | - Sharon Hutchinson
- School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Lisa Maher
- Viral Hepatitis Epidemiology and Prevention Program, Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | - Jenny Iversen
- Viral Hepatitis Epidemiology and Prevention Program, Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | - Noel Craine
- Health Protection Division, Public Health Wales, Cardiff, UK
| | - Avril Taylor
- School of Media Society and Culture, University of the West of Scotland, Paisley, UK
| | - Alison Munro
- School of Social Science, University of the West of Scotland, Paisley, UK
| | - John Parry
- Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK
| | - Josie Smith
- Health Protection Division, Public Health Wales, Cardiff, UK
| | - Peter Vickerman
- School of Social and Community Medicine, University of Bristol, Bristol, UK
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Zelenev A, Long E, Bazazi AR, Kamarulzaman A, Altice FL. The complex interplay of social networks, geography and HIV risk among Malaysian Drug Injectors: Results from respondent-driven sampling. THE INTERNATIONAL JOURNAL OF DRUG POLICY 2016; 37:98-106. [PMID: 27639995 DOI: 10.1016/j.drugpo.2016.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 07/11/2016] [Accepted: 08/08/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND HIV is primarily concentrated among people who inject drugs (PWID) in Malaysia, where currently HIV prevention and treatment coverage is inadequate. To improve the targeting of interventions, we examined HIV clustering and the role that social networks and geographical distance play in influencing HIV transmission among PWID. METHODS Data were derived from a respondent-driven survey sample (RDS) collected during 2010 of 460 PWID in greater Kuala Lumpur. Analysis focused on socio-demographic, clinical, behavioural, and network information. Spatial probit models were developed based on a distinction between the influence of peers (individuals nominated through a recruitment network) and neighbours (residing a close distance to the individual). The models were expanded to account for the potential influence of the network formation. RESULTS Recruitment patterns of HIV-infected PWID clustered both spatially and across the recruitment networks. In addition, HIV-infected PWID were more likely to have peers and neighbours who inject with clean needles were HIV-infected and lived nearby (<5km), more likely to have been previously incarcerated, less likely to use clean needles (26.8% vs 53.0% of the reported injections, p<0.01), and have fewer recent injection partners (2.4 vs 5.4, p<0.01). The association between the HIV status of peers and neighbours remained significantly correlated even after controlling for unobserved variation related to network formation and sero-sorting. CONCLUSION The relationship between HIV status across networks and space in Kuala Lumpur underscores the importance of these factors for surveillance and prevention strategies, and this needs to be more closely integrated. RDS can be applied to identify injection network structures, and this provides an important mechanism for improving public health surveillance, accessing high-risk populations, and implementing risk-reduction interventions to slow HIV transmission.
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Affiliation(s)
- Alexei Zelenev
- Department of Internal Medicine, Section of Infectious Diseases, AIDS Program, Yale School of Medicine, 135 College St., Suite 323, New Haven, CT 06510, USA.
| | - Elisa Long
- UCLA Anderson School of Management, Decisions, Operations & Technology Management Department, Los Angeles, CA, USA
| | - Alexander R Bazazi
- Department of Internal Medicine, Section of Infectious Diseases, AIDS Program, Yale School of Medicine, 135 College St., Suite 323, New Haven, CT 06510, USA; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Adeeba Kamarulzaman
- Department of Internal Medicine, Section of Infectious Diseases, AIDS Program, Yale School of Medicine, 135 College St., Suite 323, New Haven, CT 06510, USA; Centre of Excellence for Research in AIDS (CERiA), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Frederick L Altice
- Department of Internal Medicine, Section of Infectious Diseases, AIDS Program, Yale School of Medicine, 135 College St., Suite 323, New Haven, CT 06510, USA; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA; Centre of Excellence for Research in AIDS (CERiA), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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9
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Harker Burnhams N, Laubscher R, Howell S, Shaw M, Erasmus J, Townsend L. Using respondent-driven sampling (RDS) to recruit illegal poly-substance users in Cape Town, South Africa: implications and future directions. Subst Abuse Treat Prev Policy 2016; 11:31. [PMID: 27586507 PMCID: PMC5007993 DOI: 10.1186/s13011-016-0074-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 08/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND South Africa continues to witness an increase in illicit poly-substance use, although a precise measurement continues to be compounded by difficulties in accessing users. In a pilot attempt to use respondent-driven sampling (RDS)-a chain referral sampling method used to access populations of individuals who are 'hard-to-reach'-this article documents the feasibility of the method as recorded in a simultaneously run, multisite, poly-substance study in Cape Town. Here we aim to a) document the piloting of RDS among poly-substance users in the three socio-economic disparate communities targeted; b) briefly document the results; and c) review the utility of RDS as a research tool. METHODS Three cross-sectional surveys using standard RDS procedures were used to recruit active poly-substance users and were concurrently deployed in three sites. Formative research was initially conducted to assess the feasibility of the survey. To determine whether RDS could be used to successfully recruit poly-substance users, social network characteristics, such as network size was determined. RESULTS A 42.5 % coupon return rate was recorded in total from 12 initial seeds. There were vast differences in the recruitment chains of individual seeds-two generated more than 90 recruits, and 2 of the 10 recruitment chains showing a length of more than 10 waves. Findings include evidence of the use of 3 or more substances in all three sites, high levels of unemployment among users, with more than a third of participants in two sites reporting arrest for drug use in the past 12 months. CONCLUSIONS Our results indicate that RDS was a feasible and acceptable sampling method for recruiting participants who may not otherwise be accessible. Future studies can use RDS to recruit such cohorts, and the method could form part of broader efforts to document vulnerable populations.
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Affiliation(s)
- Nadine Harker Burnhams
- Alcohol, Tobacco and Other Drug Research Unit, South African Medical Research Council, P.O. Box 19070, Tygerberg, 7505 Cape Town, South Africa
- School of Public Health and Family Medicine, Falmouth Building, Faculty of Health Sciences University of Cape Town, 7701 Cape Town, South Africa
| | - Ria Laubscher
- Biostatistics Unit, South African Medical Research Council, P.O. Box 19070, Tygerberg, Cape Town, 7505 South Africa
| | - Simon Howell
- Centre for Criminology, University of Cape Town Rondebosch, Private Bag x3, Cape Town, 7701 South Africa
- Centre of Criminology, Private Bag x3, Cape Town, 7701 South Africa
| | - Mark Shaw
- Centre for Criminology, University of Cape Town Rondebosch, Private Bag x3, Cape Town, 7701 South Africa
- Centre of Criminology, Private Bag x3, Cape Town, 7701 South Africa
| | - Jodilee Erasmus
- Alcohol, Tobacco and Other Drug Research Unit, South African Medical Research Council, P.O. Box 19070, Tygerberg, 7505 Cape Town, South Africa
| | - Loraine Townsend
- Health Systems Research Unit, South African Medical Research Council, P.O. Box 19070, Tygerberg, Cape Town, 7505 South Africa
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10
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Johnston LG, Hakim AJ, Dittrich S, Burnett J, Kim E, White RG. A Systematic Review of Published Respondent-Driven Sampling Surveys Collecting Behavioral and Biologic Data. AIDS Behav 2016; 20:1754-76. [PMID: 26992395 DOI: 10.1007/s10461-016-1346-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Reporting key details of respondent-driven sampling (RDS) survey implementation and analysis is essential for assessing the quality of RDS surveys. RDS is both a recruitment and analytic method and, as such, it is important to adequately describe both aspects in publications. We extracted data from peer-reviewed literature published through September, 2013 that reported collected biological specimens using RDS. We identified 151 eligible peer-reviewed articles describing 222 surveys conducted in seven regions throughout the world. Most published surveys reported basic implementation information such as survey city, country, year, population sampled, interview method, and final sample size. However, many surveys did not report essential methodological and analytical information for assessing RDS survey quality, including number of recruitment sites, seeds at start and end, maximum number of waves, and whether data were adjusted for network size. Understanding the quality of data collection and analysis in RDS is useful for effectively planning public health service delivery and funding priorities.
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Affiliation(s)
- Lisa G Johnston
- University of California, San Francisco, Global Health Sciences, San Francisco, CA, USA.
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA.
| | - Avi J Hakim
- Division of Global HIV/AIDS, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Samantha Dittrich
- Division of Global HIV/AIDS, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Janet Burnett
- Division of Global HIV/AIDS, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Evelyn Kim
- Division of Global HIV/AIDS, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Richard G White
- CMMID and Faculty of Epidemiology & Population Health, London School of Hygiene and Tropical Medicine, London, UK
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11
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Feehan DM, Salganik MJ. Generalizing the Network Scale-Up Method: A New Estimator for the Size of Hidden Populations. SOCIOLOGICAL METHODOLOGY 2016; 46:153-186. [PMID: 29375167 PMCID: PMC5783650 DOI: 10.1177/0081175016665425] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The network scale-up method enables researchers to estimate the size of hidden populations, such as drug injectors and sex workers, using sampled social network data. The basic scale-up estimator offers advantages over other size estimation techniques, but it depends on problematic modeling assumptions. We propose a new generalized scale-up estimator that can be used in settings with non-random social mixing and imperfect awareness about membership in the hidden population. Further, the new estimator can be used when data are collected via complex sample designs and from incomplete sampling frames. However, the generalized scale-up estimator also requires data from two samples: one from the frame population and one from the hidden population. In some situations these data from the hidden population can be collected by adding a small number of questions to already planned studies. For other situations, we develop interpretable adjustment factors that can be applied to the basic scale-up estimator. We conclude with practical recommendations for the design and analysis of future studies.
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Affiliation(s)
- Dennis M Feehan
- Department of Demography, University of California, Berkeley, CA, USA
| | - Matthew J Salganik
- Office of Population Research, Princeton University, Princeton, NJ, USA
- Department of Sociology, Princeton University, Princeton, NJ, USA
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12
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Hickman M, De Angelis D, Vickerman P, Hutchinson S, Martin NK. Hepatitis C virus treatment as prevention in people who inject drugs: testing the evidence. Curr Opin Infect Dis 2015; 28:576-82. [PMID: 26524330 PMCID: PMC4659818 DOI: 10.1097/qco.0000000000000216] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW The majority of hepatitis C virus (HCV) infections in the United Kingdom and many developing countries were acquired through injecting. New clinical guidance suggests that HCV treatment should be offered to people with a transmission risk - such as people who inject drugs (PWID) - irrespective of severity of liver disease. We consider the strength of the evidence base and potential problems in evaluating HCV treatment as prevention among PWID. RECENT FINDINGS There is good theoretical evidence from dynamic models that HCV treatment for PWID could reduce HCV chronic prevalence and incidence among PWID. Economic evaluations from high-income settings have suggested HCV treatment for PWID is cost-effective, and that in many settings HCV treatment of PWID could be more cost-effective than treating those at an equivalent stage with no ongoing transmission risk. Epidemiological studies of older interferon treatments have suggested that PWID can achieve similar treatment outcomes to other patient groups treated for chronic HCV. Impact and cost-effectiveness of HCV treatment is driven by the potential 'prevention benefit' of treating PWID. Model projections suggest that more future infections, end stage liver disease, and HCV-related deaths will be averted than lost through reinfection of PWID treated successfully for HCV. However, there is to date no empirical evidence from trials or observational studies that test the model projections and 'prevention benefit' hypothesis. In part this is because of uncertainty in the evidence base but also there is unlikely to have been a change in HCV prevalence due to HCV treatment because PWID HCV treatment rates historically in most sites have been low, and any scale-up and switch to the new direct acting antiviral has not yet occurred. There are a number of key uncertainties in the data available on PWID that need to be improved and addressed to evaluate treatment as prevention. These include estimates of the prevalence of PWID, measurements of HCV chronic prevalence and incidence among PWID, and how to interpret reinfection rates as potential outcome measures. SUMMARY Eliminating HCV through scaling up treatment is a theoretical possibility. But empirical data are required to demonstrate that HCV treatment can reduce HCV transmission, which will require an improved evidence base and analytic framework for measuring PWID and HCV prevalence.
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Affiliation(s)
- Matthew Hickman
- aSchool of Social and Community Medicine, University of Bristol bMRC Biostatistics Unit, University of Cambridge and Public Health England cGlasgow Caledonian University and Health Protection Scotland, UK dDivision of Global Public Health, University of California San Diego, California, USA
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13
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Defining populations and injecting parameters among people who inject drugs: Implications for the assessment of hepatitis C treatment programs. THE INTERNATIONAL JOURNAL OF DRUG POLICY 2015; 26:950-7. [DOI: 10.1016/j.drugpo.2015.07.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 06/12/2015] [Accepted: 07/13/2015] [Indexed: 01/19/2023]
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14
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Vickerman P, Platt L, Jolley E, Rhodes T, Kazatchkine MD, Latypov A. Controlling HIV among people who inject drugs in Eastern Europe and Central Asia: insights from modeling. THE INTERNATIONAL JOURNAL OF DRUG POLICY 2015; 25:1163-73. [PMID: 25449056 DOI: 10.1016/j.drugpo.2014.09.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/24/2014] [Accepted: 09/26/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Although there is evidence of the effectiveness of needle and syringe programme (NSP), opioid substitution therapy (OST) and antiretroviral therapy (ART) in reducing HIV prevalence, most Central and Eastern European sub-regions still have low or no coverage of most or all of these interventions. METHODS We conducted a modelling analysis to consider the potential impact on HIV incidence and prevalence of OST, NSP and ART in three illustrative epidemic scenarios: Russia (St. Petersburg); Estonia (Tallinn) and Tajikistan (Dushanbe). For each intervention, we consider the coverage needed of each intervention separately or in combination to: (1) achieve a 30% or 50% relative reduction in HIV incidence or prevalence over 10 years; and (2) reduce HIV incidence to below 1% or HIV prevalence below 10% after 20 years. A sensitivity analysis for St. Petersburg considered the implications of greater on no risk heterogeneity, none or more sexual HIV transmission, like-with-like mixing, different injecting cessation rates and assuming a lower HIV acute phase cofactor. RESULTS For St. Petersburg, when OST, NSP and ART are combined, only 14% coverage of each intervention is required to achieve a 30% reduction in HIV incidence over 10 years. Similar findings are obtained for Tallinn and Dushanbe. In order to achieve the same reductions in HIV prevalence over 10 years, over double the coverage level is required relative to what was needed to achieve the same reduction in HIV incidence in that setting. To either reduce HIV incidence to less than 1% or HIV prevalence to less than 10% over 20 years, with all interventions combined, projections suggest that very high coverage levels of 74–85% are generally required for the higher prevalence settings of Tallinn and St. Petersburg, whereas lower coverage levels (23–34%) are needed in Dushanbe. Coverage requirements are robust to increased sexual HIV transmission, risk heterogeneity and like-with-like mixing, as well as to assuming a lower HIV acute phase cofactor or different injecting cessation rate. CONCLUSION The projections suggest that high but achievable coverage levels of NSP can result in large decreases (30%) in HIV incidence in settings with high HIV prevalence among PWID. Required coverage levels are much lower when interventions are combined or in lower prevalence settings. However, even when all three interventions are combined, the targets of reducing HIV incidence to less than 1% or prevalence to less than 10% in 20 years may be hard to achieve except in lower prevalence settings.
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Affiliation(s)
- Peter Vickerman
- School of Social and Community Medicine, University of Bristol, UK.
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15
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Mills HL, Johnson S, Hickman M, Jones NS, Colijn C. Errors in reported degrees and respondent driven sampling: implications for bias. Drug Alcohol Depend 2014; 142:120-6. [PMID: 24999062 PMCID: PMC4150985 DOI: 10.1016/j.drugalcdep.2014.06.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/05/2014] [Accepted: 06/05/2014] [Indexed: 01/26/2023]
Abstract
BACKGROUND Respondent Driven Sampling (RDS) is a network or chain sampling method designed to access individuals from hard-to-reach populations such as people who inject drugs (PWID). RDS surveys are used to monitor behaviour and infection occurence over time; these estimations require adjusting to account for over-sampling of individuals with many contacts. Adjustment is done based on individuals' reported total number of contacts, assuming these are correct. METHODS Data on the number of contacts (degrees) of individuals sampled in two RDS surveys in Bristol, UK, show larger numbers of individuals reporting numbers of contacts in multiples of 5 and 10 than would be expected at random. To mimic these patterns we generate contact networks and explore different methods of mis-reporting degrees. We simulate RDS surveys and explore the sensitivity of adjusted estimates to these different methods. RESULTS We find that inaccurate reporting of degrees can cause large and variable bias in estimates of prevalence or incidence. Our simulations imply that paired RDS surveys could over- or under-estimate any change in prevalence by as much as 25%. These are particularly sensitive to inaccuracies in the degree estimates of individuals with who have low degree. CONCLUSIONS There is a substantial risk of bias in estimates from RDS if degrees are not correctly reported. This is particularly important when analysing consecutive RDS samples to assess trends in population prevalence and behaviour. RDS questionnaires should be refined to obtain high resolution degree information, particularly from low-degree individuals. Additionally, larger sample sizes can reduce uncertainty in estimates.
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Affiliation(s)
- Harriet L. Mills
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Dynamics, Imperial College London, St Mary's Hospital, Norfolk Place, London W2 1PG, UK,Corresponding author. Tel.: +44 20 7594 1379.
| | - Samuel Johnson
- Department of Mathematics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Matthew Hickman
- School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK
| | - Nick S. Jones
- Department of Mathematics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Caroline Colijn
- Department of Mathematics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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16
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Zimmermann R, Marcus U, Schäffer D, Leicht A, Wenz B, Nielsen S, Santos-Hövener C, Ross RS, Stambouli O, Ratsch BA, Bannert N, Bock CT, Kücherer C, Hamouda O. A multicentre sero-behavioural survey for hepatitis B and C, HIV and HTLV among people who inject drugs in Germany using respondent driven sampling. BMC Public Health 2014; 14:845. [PMID: 25124485 PMCID: PMC4247126 DOI: 10.1186/1471-2458-14-845] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 07/25/2014] [Indexed: 01/03/2023] Open
Abstract
Background People who inject drugs are at high risk for hepatitis B, hepatitis C and HIV. HTLV was reported by neighboring countries to be prevalent in this population, but the situation for Germany is unclear. To generate seroprevalence and related behavioural data and to enhance prevention efforts against these infections for drug users in Germany, a multicentre sero- and behavioural survey was initiated. People who inject drugs are not well reached by services for testing and counselling for blood-borne infections in Germany. An interventional part of the study is intended to prove feasibility and acceptance of testing and counselling in low-threshold drop-in settings. Methods/Design Between May 2011 and March 2015, eligible participants (persons having injected drugs within the last 12 months, aged 16 years+, and living in the study city) are recruited by respondent driven sampling, using low-threshold drop-in facilities as study-sites in eight German cities with large drug scenes. Calculated sample size is 2,033 participants. Capillary blood samples collected as dried blood spots are anonymously tested for serological and molecular markers of hepatitis B and C, HIV, and HTLV I and II. A detailed face-to-face-interview about hepatitis- and HIV-related knowledge, former testing, imprisonment, sexual and injecting risk behaviour is conducted with participants. Staff is trained to offer pre- and post-test-counselling of blood-borne infections and HIV rapid testing to participants. Discussion We chose respondent driven sampling for recruitment of participants to improve representativeness of results. Persons, who are not reached by the facility where the study is conducted, are aimed to be included by recruitment through their personal social network of injecting drug users. To reduce differential biases in the questions on knowledge of transmission and prevention of infections, we present true statements on hepatitis B, C and HIV, their possible routes of transmission and measures of prevention to participants. Participants are told that the statements are true and are asked to answer if they knew this fact already or if it is new to them. In case of knowledge gaps they are offered free targeted counselling as well as free HIV rapid testing and post-test counselling of HIV and hepatitis test results.
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Affiliation(s)
- Ruth Zimmermann
- Department for Infectious Disease Epidemiology, Division for HIV/AIDS, STI and Blood-borne Infections, Robert Koch Institute, Berlin, Germany.
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Vickerman P, Hickman M. Commentary on de Vos et al. (2013): can ecological trends in HIV or HCV incidence be used to assess intervention impact? Addiction 2013; 108:1082-3. [PMID: 23659844 DOI: 10.1111/add.12206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter Vickerman
- Social and Mathematical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK.
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Should associations between HIV-related risk perceptions and behaviors or intentions be positive or negative? PLoS One 2012; 7:e52124. [PMID: 23284896 PMCID: PMC3526527 DOI: 10.1371/journal.pone.0052124] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/08/2012] [Indexed: 11/24/2022] Open
Abstract
Risk perceptions are important in HIV research and interventions; mixed results were found between HIV-related perceptions and behaviors. We interviewed 377 sexually active injecting drug users in China, finding mixed associations between HIV-related risk perception assessed by two general measures and two previous risk behaviors (syringe sharing: p<.05; unprotected sex: p>.05) – partially supporting the ‘reflective hypothesis’ that reflection on previous behaviors increases risk perceptions. When we use specific measures for risk perceptions (HIV transmission via unprotected sex with specific types of sex partner and via syringe sharing) and use behavioral intention to adopt protective risk behaviors (condom use and avoid syringe sharing totally) as dependent variables, positive significant associations were observed – supporting the motivational hypothesis that risk perceptions motivate one to adopt protective behaviors. The direction and significance of the associations of concern depends on types of measures used. It has important implications on research design, data interpretation and services.
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