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Bollerup S, Wessman M, Hansen JF, Nielsen S, Hay G, Cowan S, Krarup H, Omland L, Jepsen P, Weis N, Christensen PB. Increasing prevalence of chronic hepatitis B virus infection and low linkage to care in Denmark on 31 December 2016 - an update based on nationwide registers. Infect Dis (Lond) 2023; 55:17-26. [PMID: 36221255 DOI: 10.1080/23744235.2022.2125065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES We aimed to update the estimated prevalence of both diagnosed and undiagnosed chronic hepatitis B virus infection in Denmark. Moreover, we aimed to determine the number of people with chronic hepatitis B virus infection in specialised care and to assess the completeness of reporting to the national register of communicable diseases. METHODS Using four registers with national coverage, we identified all individuals registered with chronic hepatitis B virus infection, aged 16 years or older, and alive in Denmark on 31 December 2016. The diagnosed population was then estimated using capture-recapture analysis. The undiagnosed population was estimated using data from the Danish pregnancy screening program. RESULTS We estimated that 14,548 individuals were living with chronic hepatitis B virus infection corresponding to 0.3% of the Danish population. Of them, 13,530 (93%) were diagnosed and 7942 (55%) were registered in one or more of the source registers. Only 4297 (32%) diagnosed individuals had attended specialised care and only 3289 cases (24%) were reported to the Danish communicable disease register. CONCLUSION The prevalence of chronic hepatitis B virus infection increased from 2007 to 2017. The majority that had been diagnosed did not receive care as recommended by national guidelines and were not reported to the communicable diseases register responsible for hepatitis B virus surveillance. Future efforts should focus on linking individuals diagnosed with chronic hepatitis B virus infection to specialised care and improving reporting to the hepatitis B virus surveillance system.
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Affiliation(s)
- Signe Bollerup
- Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - Maria Wessman
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
| | | | - Stine Nielsen
- Department of Infectious Diseases, Odense University Hospital, Odense, Denmark
| | - Gordon Hay
- Centre for Public Health, Liverpool John Moores University, Liverpool, United Kingdom
| | - Susan Cowan
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
| | - Henrik Krarup
- Department of Molecular Diagnostics, Aalborg University Hospital, Aalborg, Denmark.,Department of Medical Gastroenterology, Aalborg University Hospital, Aalborg, Denmark
| | - Lars Omland
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Peter Jepsen
- Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.,Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Nina Weis
- Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peer Brehm Christensen
- Department of Infectious Diseases, Odense University Hospital, Odense, Denmark.,Clinical Institute, University of Southern Denmark, Odense, Denmark
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Nunes A, Trappenberg T, Alda M. The definition and measurement of heterogeneity. Transl Psychiatry 2020; 10:299. [PMID: 32839448 PMCID: PMC7445182 DOI: 10.1038/s41398-020-00986-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 07/21/2020] [Accepted: 08/10/2020] [Indexed: 12/31/2022] Open
Abstract
Heterogeneity is an important concept in psychiatric research and science more broadly. It negatively impacts effect size estimates under case-control paradigms, and it exposes important flaws in our existing categorical nosology. Yet, our field has no precise definition of heterogeneity proper. We tend to quantify heterogeneity by measuring associated correlates such as entropy or variance: practices which are akin to accepting the radius of a sphere as a measure of its volume. Under a definition of heterogeneity as the degree to which a system deviates from perfect conformity, this paper argues that its proper measure roughly corresponds to the size of a system's event/sample space, and has units known as numbers equivalent. We arrive at this conclusion through focused review of more than 100 years of (re)discoveries of indices by ecologists, economists, statistical physicists, and others. In parallel, we review psychiatric approaches for quantifying heterogeneity, including but not limited to studies of symptom heterogeneity, microbiome biodiversity, cluster-counting, and time-series analyses. We argue that using numbers equivalent heterogeneity measures could improve the interpretability and synthesis of psychiatric research on heterogeneity. However, significant limitations must be overcome for these measures-largely developed for economic and ecological research-to be useful in modern translational psychiatric science.
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Affiliation(s)
- Abraham Nunes
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Thomas Trappenberg
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada.
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3
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Harris RJ, Harris HE, Mandal S, Ramsay M, Vickerman P, Hickman M, De Angelis D. Monitoring the hepatitis C epidemic in England and evaluating intervention scale-up using routinely collected data. J Viral Hepat 2019; 26:541-551. [PMID: 30663179 PMCID: PMC6518935 DOI: 10.1111/jvh.13063] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/19/2018] [Indexed: 01/13/2023]
Abstract
In England, 160 000 individuals were estimated to be chronically infected with hepatitis C virus (HCV) in 2005 and the burden of severe HCV-related liver disease has increased steadily for the past 15 years. Direct-acting antiviral treatments can clear infection in most patients, motivating HCV elimination targets. However, the current burden of HCV is unknown and new methods are required to monitor progress. We employed a Bayesian back-calculation approach, combining data on severe HCV-related liver disease and disease progression, to reconstruct historical HCV incidence and estimate current prevalence in England. We explicitly modelled infections occurring in people who inject drugs, the key risk group, allowing information on the size of this population and surveillance data on HCV prevalence to inform recent incidence. We estimated that there were 143 000 chronic infections in 2015 (95% credible interval 123 000-161 000), with 34% and 54% in those with recent and past injecting drug use, respectively. Following the planned scale-up of new treatments, chronic infections were predicted to fall to 113 400 (94 900-132 400) by the end of 2018 and to 89 500 (71 300-108 600) by the end of 2020. Numbers developing severe HCV-related liver disease were predicted to fall by at least 24% from 2015 to 2020. Thus, we describe a coherent framework to monitor progress using routinely collected data, which can be extended to incorporate additional data sources. Planned treatment scale-up is likely to achieve 2020 WHO targets for HCV morbidity, but substantial efforts will be required to ensure that HCV testing and patient engagement are sufficiently high.
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Affiliation(s)
- Ross J. Harris
- Statistics Modelling and Economics DepartmentNational Infection ServicePublic Health EnglandLondonUK
| | - Helen E. Harris
- Immunisation, Hepatitis and Blood Safety DepartmentNational Infection ServicePublic Health EnglandLondonUK
| | - Sema Mandal
- Immunisation, Hepatitis and Blood Safety DepartmentNational Infection ServicePublic Health EnglandLondonUK
| | - Mary Ramsay
- Immunisation, Hepatitis and Blood Safety DepartmentNational Infection ServicePublic Health EnglandLondonUK
| | - Peter Vickerman
- Population Health SciencesBristol Medical SchoolUniversity of BristolBristolUK
| | - Matthew Hickman
- Population Health SciencesBristol Medical SchoolUniversity of BristolBristolUK
| | - Daniela De Angelis
- Statistics Modelling and Economics DepartmentNational Infection ServicePublic Health EnglandLondonUK,MRC Biostatistics UnitCambridge Institute of Public HealthCambridgeUK
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4
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Steer CD, Macleod J, Tilling K, Lim AG, Marsden J, Millar T, Strang J, Telfer M, Whitaker H, Vickerman P, Hickman M. The impact of opiate substitution treatment on mortality risk in drug addicts: a natural experiment study. HEALTH SERVICES AND DELIVERY RESEARCH 2019. [DOI: 10.3310/hsdr07030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Background
Opiate substitution treatment (OST) is the main treatment for people addicted to heroin and other opioid drugs. However, there is limited information on how the delivery of this treatment affects mortality risk.
Objectives
To investigate the associations of mortality risk with periods during treatment and following cessation of treatment, medication type, co-prescription of other medication and dosing regimens during titration and detoxification. The trends with time of prescribed medication, dose and treatment duration were also explored.
Design
Prospective longitudinal observational study.
Setting
UK primary care between 1998 and 2014.
Participants
A total of 12,780 patients receiving methadone, buprenorphine or dihydrocodeine.
Main outcome measures
All-cause mortality relating to 657 deaths and drug-related poisoning relating to 113 deaths.
Data sources
Clinical Practice Research Datalink with linked information on cause of death from the Office for National Statistics.
Results
For both outcomes, the lowest mortality risk was observed after 4 weeks of treatment and the highest risk was observed in the first 4 weeks following cessation of treatment [e.g. for drug-related poisoning, incidence rate ratio (IRR) 8.15, 95% confidence interval (CI) 5.45 to 12.19]. There was evidence that the treatment period risks varied with OST medication. The largest difference in risk was for the first 4 weeks of treatment for both outcomes, with patients on buprenorphine being at lower risk than those on methadone (e.g. for drug-related poisoning, IRR 0.08, 95% CI 0.01 to 0.48). The co-prescription of benzodiazepines was associated with linearly increasing the risk of drug-related deaths by dose (IRR 2.02, 95% CI 1.66 to 2.47), whereas z-drugs (zolpidem, zopiclone and zaleplon) were associated with increased risk of both all-cause (IRR 1.83, 95% CI 1.59 to 2.12) and drug-related (IRR 3.31, 95% CI 2.45 to 4.47) mortality. There was weak evidence that higher initial and final doses were associated with increased all-cause mortality risk. In the first 4 weeks of treatment, the risk increased by 4% for each 5-mg increment in methadone dose (1-mg increase in buprenorphine) (hazard ratio 1.04, 95% CI 1.00 to 1.09). In the first 4 weeks after treatment ceased, a similar increment in final dose increased the risk by 3% (hazard ratio 1.03, 95% CI 0.99 to 1.07). There were too few deaths to evaluate the effects on drug-related poisoning. The proportion of OST patients receiving buprenorphine increased between 1998 and 2006. Median treatment duration was consistently shorter for buprenorphine than for methadone for each year studied (overall median duration of 48 and 106 days, respectively).
Limitations
As this was an observational study, the possibility remains of bias from unmeasured factors, which covariate adjustment and inverse probability weighting can eliminate only partially.
Conclusions
Using buprenorphine as an alternative to methadone may not reduce mortality overall despite resulting in lower IRRs from shorter treatment duration. Clinical guidance needs to consider strengthening warnings about the co-prescription of a range of drugs for OST patients.
Future work
Our analyses need to be replicated using other clinical data sets in the UK and in other countries. New interventions and trials are required to investigate improving the retention of OST patients in primary care.
Funding
The National Institute for Health Research Health Services and Delivery Research programme.
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Affiliation(s)
- Colin D Steer
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - John Macleod
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kate Tilling
- 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
| | - John Marsden
- National Addiction Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Tim Millar
- Centre for Mental Health and Safety, School of Health Sciences, University of Manchester, Manchester, UK
| | - John Strang
- National Addiction Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | | | - Heather Whitaker
- Department of Mathematics and Statistics, The Open University, Milton Keynes, UK
| | - Peter Vickerman
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Matthew Hickman
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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5
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Mook P, Gardiner D, Kanagarajah S, Kerac M, Hughes G, Field N, McCarthy N, Rawlings C, Simms I, Lane C, Crook PD. Use of gender distribution in routine surveillance data to detect potential transmission of gastrointestinal infections among men who have sex with men in England. Epidemiol Infect 2018; 146:1468-1477. [PMID: 29923475 PMCID: PMC9133680 DOI: 10.1017/s0950268818001681] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/20/2018] [Accepted: 05/23/2018] [Indexed: 11/06/2022] Open
Abstract
Detecting gastrointestinal (GI) infection transmission among men who have sex with men (MSM) in England is complicated by a lack of routine sexual behavioural data. We investigated whether gender distributions might generate signals for increased transmission of GI pathogens among MSM. We examined the percentage male of laboratory-confirmed patient-episodes for patients with no known travel history for 10 GI infections of public health interest in England between 2003 and 2013, stratified by age and region. An adult male excess was observed for Shigella spp. (annual maximum 71% male); most pronounced for those aged 25-49 years and living in London, Brighton and Manchester. An adult male excess was observed every year for Entamoeba histolytica (range 59.8-76.1% male), Giardia (53.1-57.6%) and Campylobacter (52.1-53.5%) and for a minority of years for hepatitis A (max. 69.8%) and typhoidal salmonella (max. 65.7%). This approach generated a signal for excess male episodes for six GI pathogens, including a characterised outbreak of Shigella among MSM. Stratified analyses by geography and age group were consistent with MSM transmission for Shigella. Optimisation and routine application of this technique by public health authorities elsewhere might help identify potential GI infection outbreaks due to sexual transmission among MSM, for further investigation.
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Affiliation(s)
- P. Mook
- Field Epidemiology Service, Public Health England, London, UK
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - D. Gardiner
- Field Epidemiology Service, Public Health England, London, UK
| | - S. Kanagarajah
- Field Epidemiology Service, Public Health England, London, UK
| | - M. Kerac
- Field Epidemiology Service, Public Health England, London, UK
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK
- Department of Epidemiology & Public Health, Leonard Cheshire Disability & Inclusive Development Centre, University College London, London, UK
| | - G. Hughes
- HIV and STI Department, National Infection Service, Public Health England, London, UK
| | - N. Field
- HIV and STI Department, National Infection Service, Public Health England, London, UK
- Centre for Molecular Epidemiology and Translational Research, Institute for Global Health, University College London, London, UK
| | - N. McCarthy
- Field Epidemiology Service, Public Health England, London, UK
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
- National Institute Health Research (NIHR) Health Protection Research Unit in Gastrointestinal Infections, London, UK
| | - C. Rawlings
- Field Epidemiology Service, Public Health England, London, UK
| | - I. Simms
- HIV and STI Department, National Infection Service, Public Health England, London, UK
| | - C. Lane
- Gastrointestinal, Emerging and Zoonotic Infections Department, Public Health England, London, UK
| | - P. D. Crook
- Field Epidemiology Service, Public Health England, London, UK
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6
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Jones HE, Goulding N, Hickman M. Commentary on Lai et al. (2018): Potential and limitations of wastewater-based epidemiology in monitoring substance use. Addiction 2018; 113:1137-1138. [PMID: 29732695 DOI: 10.1111/add.14207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 02/27/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Hayley E Jones
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Neil Goulding
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Matthew Hickman
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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7
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Wesson P, Reingold A, McFarland W. Theoretical and Empirical Comparisons of Methods to Estimate the Size of Hard-to-Reach Populations: A Systematic Review. AIDS Behav 2017; 21:2188-2206. [PMID: 28078496 DOI: 10.1007/s10461-017-1678-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Worldwide, the HIV epidemic is concentrated among hidden populations (i.e., female sex workers, men who have sex with men, and people who inject drugs). To understand the true scope and scale of the HIV epidemic, estimates of the sizes of these populations are needed. Various methods are available to enumerate hidden populations, but the degree of agreement between these methods has not been formally evaluated. We systematically reviewed the peer-reviewed literature to assess the extent to which different population size estimation methods provide the same estimate of a target population. Of the 341 studies identified from our search, 25 met our eligibility criteria. Twenty-one unique methods were documented. The service multiplier method was the most common in the review. Eighty target populations were estimated, covering 16 countries. We observed variable population size estimates, with little agreement between methods. We note trends in the relative performance of individual methods.
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Affiliation(s)
- Paul Wesson
- Center for AIDS Prevention Studies, TAPS Fellowship Program, University of California, San Francisco, Mission Hall, 550 16th Street, 3rd Floor, Mail Code 0886, San Francisco, CA, 94158, USA.
- Department of Epidemiology, School of Public Health, University of California, Berkeley, Berkeley, CA, USA.
| | - Arthur Reingold
- Department of Epidemiology, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Willi McFarland
- Department of Epidemiology, University of California, San Francisco, San Francisco, CA, USA
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Dombrowski K, Sittner K, Crawford D, Welch-Lazoritz M, Habecker P, Khan B. Network Approaches to Substance Use and HIV/Hepatitis C Risk among Homeless Youth and Adult Women in the United States: A Review. Health (London) 2016; 8:1143-1165. [PMID: 28042394 PMCID: PMC5193114 DOI: 10.4236/health.2016.812119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During the United States economic recession of 2008-2011, the number of homeless and unstably housed people in the United States increased considerably. Homeless adult women and unaccompanied homeless youth make up the most marginal segments of this population. Because homeless individuals are a hard to reach population, research into these marginal groups has traditionally been a challenge for researchers interested in substance abuse and mental health. Network analysis techniques and research strategies offer means for dealing with traditional challenges such as missing sampling frames, variation in definitions of homelessness and study inclusion criteria, and enumeration/population estimation procedures. This review focuses on the need for, and recent steps toward, solutions to these problems that involve network science strategies for data collection and analysis. Research from a range of fields is reviewed and organized according to a new stress process framework aimed at understanding how homeless status interacts with issues related to substance abuse and mental health. Three types of network innovation are discussed: network scale-up methods, a network ecology approach to social resources, and the integration of network variables into the proposed stress process model of homeless substance abuse and mental health. By employing network methods and integrating these methods into existing models, research on homeless and unstably housed women and unaccompanied young people can address existing research challenges and promote more effective intervention and care programs.
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Affiliation(s)
- Kirk Dombrowski
- Department of Sociology, University of Nebraska-Lincoln, Lincoln, USA
| | - Kelley Sittner
- Department of Sociology, Oklahoma State University, Stillwater, USA
| | | | | | - Patrick Habecker
- Department of Sociology, University of Nebraska-Lincoln, Lincoln, USA
| | - Bilal Khan
- Department of Sociology, University of Nebraska-Lincoln, Lincoln, USA
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9
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Hay G, Richardson C. Estimating the Prevalence of Drug Use Using Mark-Recapture Methods. Stat Sci 2016. [DOI: 10.1214/16-sts553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Jones HE, Welton NJ, Ades AE, Pierce M, Davies W, Coleman B, Millar T, Hickman M. Problem drug use prevalence estimation revisited: heterogeneity in capture-recapture and the role of external evidence. Addiction 2016; 111:438-47. [PMID: 26499106 PMCID: PMC4981907 DOI: 10.1111/add.13222] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/10/2015] [Accepted: 10/15/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND AIMS Capture-recapture (CRC) analysis is recommended for estimating the prevalence of problem drug use or people who inject drugs (PWID). We aim to demonstrate how naive application of CRC can lead to highly misleading results, and to suggest how the problems might be overcome. METHODS We present a case study of estimating the prevalence of PWID in Bristol, UK, applying CRC to lists in contact with three services. We assess: (i) sensitivity of results to different versions of the dominant (treatment) list: specifically, to inclusion of non-incident cases and of those who were referred directly from one of the other services; (ii) the impact of accounting for a novel covariate, housing instability; and (iii) consistency of CRC estimates with drug-related mortality data. We then incorporate formally the drug-related mortality data and lower bounds for prevalence alongside the CRC into a single coherent model. RESULTS Five of 11 models fitted the full data equally well but generated widely varying prevalence estimates, from 2740 [95% confidence interval (CI) = 2670, 2840] to 6890 (95% CI = 3740, 17680). Results were highly sensitive to inclusion of non-incident cases, demonstrating the presence of considerable heterogeneity, and were sensitive to a lesser extent to inclusion of direct referrals. A reduced data set including only incident cases and excluding referrals could be fitted by simpler models, and led to much greater consistency in estimates. Accounting for housing stability improved model fit considerably more than did the standard covariates of age and gender. External data provided validation of results and aided model selection, generating a final estimate of the number of PWID in Bristol in 2011 of 2770 [95% credible interval (Cr-I) = 2570, 3110] or 0.9% (95% Cr-I = 0.9, 1.0%) of the population aged 15-64 years. CONCLUSIONS Steps can be taken to reduce bias in capture-recapture analysis, including: careful consideration of data sources, reduction of lists to less heterogeneous subsamples, use of covariates and formal incorporation of external data.
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Affiliation(s)
- Hayley E. Jones
- School of Social and Community MedicineUniversity of BristolBristolUK
| | - Nicky J. Welton
- School of Social and Community MedicineUniversity of BristolBristolUK
| | - A. E. Ades
- School of Social and Community MedicineUniversity of BristolBristolUK
| | - Matthias Pierce
- Institute of Brain, Behaviour and Mental HealthUniversity of ManchesterManchesterUK
| | - Wyn Davies
- Safer Bristol PartnershipBristol City CouncilBristolUK
| | - Barbara Coleman
- Public Health Commissioning and PerformanceBristol City CouncilBristolUK
| | - Tim Millar
- Institute of Brain, Behaviour and Mental HealthUniversity of ManchesterManchesterUK
| | - Matthew Hickman
- School of Social and Community MedicineUniversity of BristolBristolUK
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11
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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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12
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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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13
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Increased uptake and new therapies are needed to avert rising hepatitis C-related end stage liver disease in England: modelling the predicted impact of treatment under different scenarios. J Hepatol 2014; 61:530-7. [PMID: 24824282 DOI: 10.1016/j.jhep.2014.05.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 02/28/2014] [Accepted: 05/03/2014] [Indexed: 12/24/2022]
Abstract
BACKGROUND & AIMS Hepatitis C (HCV) related disease in England is predicted to rise, and it is unclear whether treatment at current levels will be able to avert this. The aim of this study was to estimate the number of people with chronic HCV infection in England that are treated and assess the impact and costs of increasing treatment uptake. METHODS Numbers treated were estimated using national data sources for pegylated interferon supplied, dispensed, or purchased from 2006 to 2011. A back-calculation approach was used to project disease burden over the next 30 years and determine outcomes under various scenarios of treatment uptake. RESULTS 5000 patients were estimated to have been treated in 2011 and 28,000 in total from 2006 to 2011; approximately 3.1% and 17% respectively of estimated chronic infections. Without treatment, incident cases of decompensated cirrhosis and hepatocellular carcinoma were predicted to increase until 2035 and reach 2290 cases per year. Treatment at current levels should reduce incidence by 600 cases per year, with a peak around 2030. Large increases in treatment are needed to halt the rise; and with more effective treatment the best case scenario predicts incidence of around 500 cases in 2030, although treatment uptake must still be increased considerably to achieve this. CONCLUSIONS If the infected population is left untreated, the number of patients with severe HCV-related disease will continue to increase and represent a substantial future burden on healthcare resources. This can be mitigated by increasing treatment uptake, which will have the greatest impact if implemented quickly.
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Healthcare seeking and hospital admissions by people who inject drugs in response to symptoms of injection site infections or injuries in three urban areas of England. Epidemiol Infect 2014; 143:120-31. [PMID: 24568684 DOI: 10.1017/s0950268814000284] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
People who inject drugs (PWID) are vulnerable to infections and injuries at injection sites. The factors associated with reporting symptoms of these, seeking related advice, and hospital admission are examined. PWID were recruited in Birmingham, Bristol and Leeds using respondent-driven sampling (N = 855). During the preceding year, 48% reported having redness, swelling and tenderness (RST), 19% an abscess, and 10% an open wound at an injection site. Overall, 54% reported ⩾1 symptoms, with 45% of these seeking medical advice (main sources emergency departments and General Practitioners). Advice was often sought ⩾5 days after the symptom first appeared (44% of those seeking advice about an abscess, 45% about an open wound, and 35% for RST); the majority received antibiotics. Overall, 9·5% reported hospital admission during the preceding year. Ever being diagnosed with septicaemia and endocarditis were reported by 8·8% and 2·9%, respectively. Interventions are needed to reduce morbidity, healthcare burden and delays in accessing treatment.
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15
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Hickman M, De Angelis D, Jones H, Harris R, Welton N, Ades AE. Multiple parameter evidence synthesis--a potential solution for when information on drug use and harm is in conflict. Addiction 2013; 108:1529-31. [PMID: 23600694 DOI: 10.1111/add.12185] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The quality of the evidence on estimating drug-related harm is not yet as advanced as that for intervention effectiveness. Multiple parameter evidence synthesis offers a potential solution, in which 'all available evidence' is combined into a single coherent model.We present a case study of estimating the number of people infected with hepatitis C.
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Affiliation(s)
- Matthew Hickman
- School of Social & Community Medicine; University of Bristol; Bristol; UK
| | | | - Hayley Jones
- School of Social & Community Medicine; University of Bristol; Bristol; UK
| | | | - Nicky Welton
- School of Social & Community Medicine; University of Bristol; Bristol; UK
| | - A. E. Ades
- School of Social & Community Medicine; University of Bristol; Bristol; UK
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16
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King R, Bird SM, Overstall A, Hay G, Hutchinson SJ. Injecting drug users in Scotland, 2006: Listing, number, demography, and opiate-related death-rates. ADDICTION RESEARCH & THEORY 2013; 21:235-246. [PMID: 23730265 PMCID: PMC3665229 DOI: 10.3109/16066359.2012.706344] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 06/19/2012] [Accepted: 06/21/2012] [Indexed: 06/02/2023]
Abstract
Using Bayesian capture-recapture analysis, we estimated the number of current injecting drug users (IDUs) in Scotland in 2006 from the cross-counts of 5670 IDUs listed on four data-sources: social enquiry reports (901 IDUs listed), hospital records (953), drug treatment agencies (3504), and recent Hepatitis C virus (HCV) diagnoses (827 listed as IDU-risk). Further, we accessed exact numbers of opiate-related drugs-related deaths (DRDs) in 2006 and 2007 to improve estimation of Scotland's DRD rates per 100 current IDUs. Using all four data-sources, and model-averaging of standard hierarchical log-linear models to allow for pairwise interactions between data-sources and/or demographic classifications, Scotland had an estimated 31700 IDUs in 2006 (95% credible interval: 24900-38700); but 25000 IDUs (95% CI: 20700-35000) by excluding recent HCV diagnoses whose IDU-risk can refer to past injecting. Only in the younger age-group (15-34 years) were Scotland's opiate-related DRD rates significantly lower for females than males. Older males' opiate-related DRD rate was 1.9 (1.24-2.40) per 100 current IDUs without or 1.3 (0.94-1.64) with inclusion of recent HCV diagnoses. If, indeed, Scotland had only 25000 current IDUs in 2006, with only 8200 of them aged 35+ years, the opiate-related DRD rate is higher among this older age group than has been appreciated hitherto. There is counter-balancing good news for the public health: the hitherto sharp increase in older current IDUs had stalled by 2006.
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Affiliation(s)
- Ruth King
- School of Mathematics and Statistics, University of St Andrews , St Andrews KY16 9SS , UK
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17
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Needles and the damage done: Reasons for admission and financial costs associated with injecting drug use in a Central London Teaching Hospital. J Infect 2013; 66:95-102. [DOI: 10.1016/j.jinf.2012.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/03/2012] [Accepted: 10/07/2012] [Indexed: 11/17/2022]
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18
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Lanumteang K, Böhning D. An extension of Chao’s estimator of population size based on the first three capture frequency counts. Comput Stat Data Anal 2011. [DOI: 10.1016/j.csda.2011.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Harris RJ, Ramsay M, Hope VD, Brant L, Hickman M, Foster GR, De Angelis D. Hepatitis C prevalence in England remains low and varies by ethnicity: an updated evidence synthesis. Eur J Public Health 2011; 22:187-92. [PMID: 21708792 DOI: 10.1093/eurpub/ckr083] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Previous evidence synthesis estimates of Hepatitis C Virus (HCV) in England did not consider excess HCV risk in ethnic minority populations. We incorporate new information on HCV risk among non-injectors by ethnic group, and additional information on injecting prevalence in order to generate new and updated estimates of HCV prevalence risk in England for 2005. METHODS Bayesian evidence synthesis was used to combine multiple sources of data that directly or indirectly provide information on the populations at risk, or prevalence of HCV infection. HCV data were modelled by region, age group and sex as well as ethnicity for never-injectors and by injecting status (ex and current). RESULTS Overall HCV antibody prevalence in England was estimated at 0.67% [95% credible interval (95% CrI): 0.50-0.94] of those aged 15-59 years, or 203 000 (153 000, 286 000) individuals. HCV prevalence in never-injectors remains low, even after accounting for ethnicity, with a prevalence of 0.05% (95% CrI 0.03-0.10) in those of white/other ethnicity and 0.76% (0.48-1.23) in South Asians. Estimates are similar to 2003, although patterns of injecting drug use are different, with an older population of current injecting drug users and lower estimated numbers of ex-injectors, but higher HCV prevalence. CONCLUSIONS Incorporating updated information, including data on ethnicity and improved data on injectors, gave similar overall estimates of HCV prevalence in England. Further information on HCV in South Asians and natural history of injecting are required to reduce uncertainty of estimates. This method may be applied to other countries and settings.
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Affiliation(s)
- Ross J Harris
- Health Protection Agency Centre for Infections, London, UK.
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20
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Roberts J, Annett H, Hickman M. A systematic review of interventions to increase the uptake of opiate substitution therapy in injecting drug users. J Public Health (Oxf) 2010; 33:378-84. [DOI: 10.1093/pubmed/fdq088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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21
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Cornish R, Macleod J, Strang J, Vickerman P, Hickman M. Risk of death during and after opiate substitution treatment in primary care: prospective observational study in UK General Practice Research Database. BMJ 2010; 341:c5475. [PMID: 20978062 PMCID: PMC2965139 DOI: 10.1136/bmj.c5475] [Citation(s) in RCA: 213] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/25/2010] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To investigate the effect of opiate substitution treatment at the beginning and end of treatment and according to duration of treatment. DESIGN Prospective cohort study. Setting UK General Practice Research Database. PARTICIPANTS Primary care patients with a diagnosis of substance misuse prescribed methadone or buprenorphine during 1990-2005. 5577 patients with 267 003 prescriptions for opiate substitution treatment followed-up (17 732 years) until one year after the expiry of their last prescription, the date of death before this time had elapsed, or the date of transfer away from the practice. MAIN OUTCOME MEASURES Mortality rates and rate ratios comparing periods in and out of treatment adjusted for sex, age, calendar year, and comorbidity; standardised mortality ratios comparing opiate users' mortality with general population mortality rates. RESULTS Crude mortality rates were 0.7 per 100 person years on opiate substitution treatment and 1.3 per 100 person years off treatment; standardised mortality ratios were 5.3 (95% confidence interval 4.0 to 6.8) on treatment and 10.9 (9.0 to 13.1) off treatment. Men using opiates had approximately twice the risk of death of women (morality rate ratio 2.0, 1.4 to 2.9). In the first two weeks of opiate substitution treatment the crude mortality rate was 1.7 per 100 person years: 3.1 (1.5 to 6.6) times higher (after adjustment for sex, age group, calendar period, and comorbidity) than the rate during the rest of time on treatment. The crude mortality rate was 4.8 per 100 person years in weeks 1-2 after treatment stopped, 4.3 in weeks 3-4, and 0.95 during the rest of time off treatment: 9 (5.4 to 14.9), 8 (4.7 to 13.7), and 1.9 (1.3 to 2.8) times higher than the baseline risk of mortality during treatment. Opiate substitution treatment has a greater than 85% chance of reducing overall mortality among opiate users if the average duration approaches or exceeds 12 months. CONCLUSIONS Clinicians and patients should be aware of the increased mortality risk at the start of opiate substitution treatment and immediately after stopping treatment. Further research is needed to investigate the effect of average duration of opiate substitution treatment on drug related mortality.
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Affiliation(s)
- Rosie Cornish
- School of Social and Community Medicine, University of Bristol, Bristol BS8 2PS, UK
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22
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King R, Bird SM, Hay G, Hutchinson SJ. Estimating current injectors in Scotland and their drug-related death rate by sex, region and age-group via Bayesian capture--recapture methods. Stat Methods Med Res 2008; 18:341-59. [PMID: 19036914 DOI: 10.1177/0962280208094701] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Using Bayesian capture-recapture methods, we estimate current injectors in Scotland in 2003, and, thereby, injectors' drug-related death rates for the period 2003-2005. Four different data sources are considered [Hepatitis C Virus (HCV) database, hospital admissions, social enquiry reports, and drug misuse database reports by General Practices or Drug Treatment Agencies] which provide covariate information on sex, region (Greater Glasgow versus elsewhere in Scotland) and age group (15-34 years and 35+ years).We quantified Scotland's current injectors in 2003 at 27,400 (95% highest probability density interval: 20,700-32,100) by incorporating underlying model uncertainty in terms of the possible interactions present between data sources and/or covariates. The posterior probability was 72% that Scotland had more current injectors in 2003 than in 2000. Detailed comparison with 2000 gave evidence of importantly changed numbers of current injectors for different covariate classes.In addition, and of particular social interest, is the estimation of injectors' drug-related death rates. Expert information was used to construct upper and lower bounds on the number of drug-related deaths pertaining to injectors, which were then used to provide bounds on injectors' drug-related death rates. Failure to incorporate expert information could result in over-estimation of drug-related death rates for subclasses of injectors.
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Affiliation(s)
- Ruth King
- School of Mathematics and Statistics, University of St. Andrews, St. Andrews, UK.
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