Liverpool Skyline

Public Health Institute

Dr Gordon Hay

Dr Gordon Hay

Telephone: 0151 231 4385



Dr Gordon Hay is a Reader in Social Epidemiology within the Public Health Institute. Prior to that appointment he was a Senior Research Fellow at the Centre for Drug Misuse Research at the University of Glasgow. His research has focused on the application of epidemiological and statistical methodologies within the area of drug or alcohol use and in his new position he aims to further develop this work more into other areas of public health.

Gordon’s main research has been developing and applying statistical methods to estimate the number of people who use drugs such as heroin or crack cocaine. Traditional surveys are often inappropriate therefore other approaches, such as the capture-recapture method, have been developed. He has carried out such work at the local, national and international level and has led a programme of research studies that have produced the annual estimates of opiate / crack cocaine use in England. He is currently carrying out a study in Ireland to provide up-to-date estimates of the prevalence of opiate use.

He is the UK Scientific Expert to the EMCDDA for their Problem Drug Use Key Indicator and has carried out a range of projects for the EMCDDA and other international organisations such as the UNODC in various countries including the Baltic States and Turkey. Gordon has collaborated with qualitative and quantitative colleagues in a number of studies, including research that quantified and sought to understand benefit uptake by drug or alcohol users for the DWP.

He has been involved in a number of large-scale evaluations, such a multi-method evaluation of the UK Government funded programme of drugs prevention projects within Health Action Zones. He also led studies looking at the social and economic costs of drug use and the likely size of the Scottish drugs market. Gordon’s PhD at the University of Strathclyde used mathematical models to examine the spread of HIV amongst people who inject drugs and he still maintains an interest in blood-borne virus epidemiology and drug-related mortality and has continued to publish in these areas.

Gordon also collaborated with colleagues at the Universities of Bath and Stirling on an ESRC funded study on bereavement following substance use. A set of guidelines for practitioners has been published as part of this study.


2002, University of Glasgow, United Kingdom, MPH
1999, University of Strathclyde, United Kingdom, PhD
1991, University of Aberdeen, United Kingdom, BSc (Hons)

Academic appointments

Reader in Social Epidemiology, Public Health Institute, Liverpool John Moore University, 2016 - present
Reader in Social Epidemiology, Centre for Public Health, Liverpool John Moores University, 2012 - 2016
Senior Research Fellow, Institute of Health and Wellbeing, University of Glasgow, 2011 - 2012
Senior Research Fellow, Centre for Drug Misuse Research, University of Glasgow, 2005 - 2011
Research Fellow, Centre for Drug Misuse Research, University of Glasgow, 2000 - 2005
Research Assistant, Centre for Drug Misuse Research, University of Glasgow, 1994 - 2000



Hay G, Rael Dos Santos A, Reed H, Hope V. 2019. Estimates of the Prevalence of Opiate Use and/or Crack Cocaine Use, 2016/17: Sweep 13 report Estimates of the Prevalence of Opiate Use and/or Crack Cocaine Use, 2016/17: Sweep 13 report >Link

Journal article

Wiessing L, Ferri M, Běláčková V, Carrieri P, Friedman SR, Folch C, Dolan K, Galvin B, Vickerman P, Lazarus JV, Mravčík V, Kretzschmar M, Sypsa V, Sarasa-Renedo A, Uusküla A, Paraskevis D, Mendão L, Rossi D, van Gelder N, Mitcheson L, Paoli L, Gomez CD, Milhet M, Dascalu N, Knight J, Hay G, Kalamara E, Simon R, EUBEST working group , Comiskey C, Rossi C, Griffiths P. 2017. Monitoring quality and coverage of harm reduction services for people who use drugs: a consensus study. Harm Reduct J, 14 :19-19 >DOI >Link >Public Url

Templeton L, Valentine C, McKell J, Ford A, Velleman R, Walter T, Hay G, Bauld L, Hollywood J. 2017. Bereavement following a fatal overdose: The experiences of adults in England and Scotland Drugs: Education, Prevention and Policy, 24 :58-66 >DOI >Public Url

Hay G, Richardson C. 2016. Estimating the prevalence of drug use using mark-recapture methods Journal of Statistical Science, 31 :191-204 >DOI >Public Url

Templeton L, Ford A, McKell J, Valentine C, Walter T, Velleman R, Bauld L, Hay G, Hollywood J. 2016. Bereavement through substance use: findings from an interview study with adults in England and Scotland Addiction Research and Theory, 24 :341-354 >DOI >Public Url

Timpson H, Eckley L, Sumnall H, Pendlebury M, Hay G. 2016. “Once you’ve been there, you’re always recovering”: exploring experiences, outcomes, and benefits of substance misuse recovery Drugs and Alcohol Today, 16 :29-38 >DOI >Link >Public Url

Overstall AM, King R, Bird SM, Hutchinson SJ, Hay G. 2013. Incomplete contingency tables with censored cells with application to estimating the number of people who inject drugs in Scotland Statistics in Medicine, >DOI >Public Url

Hansen N, Hay G, Cowan S, Jepsen P, Bygum Krarup H, Obel N, Weis N, Brehm Christensen P. 2013. Hepatitis B prevalence in Denmark - An estimate based on nationwide registers and a national screening programme, as on 31 December 2007 Eurosurveillance, 18 >DOI

Bauld L, McKell J, Templeton L, Silver K, Novak C, Hay G. 2013. Pathways back to work for problem alcohol users Policy Studies, >DOI

King R, Bird SM, Overstall AM, Hay G, Hutchinson SJ. 2013. Estimating prevalence of injecting drug users and associated heroin-related death rates in England by using regional data and incorporating prior information Journal of the Royal Statistical Society. Series A: Statistics in Society, >DOI

King R, Bird SM, Overstall A, Hay G, Hutchinson SJ. 2013. Injecting drug users in Scotland, 2006: Listing, number, demography, and opiate-related death-rates Addiction Research and Theory, 21 :235-246 >DOI

Bauld L, McKell J, Carroll C, Hay G, Smith K. 2012. Benefits and employment: How problem drug users experience welfare and routes into work Journal of Social Policy, 41 :751-768 >DOI

Christensen PB, Hay G, Jepsen P, Omland LH, Just SA, Krarup HB, Weis N, Obel N, Cowan S. 2012. Hepatitis C prevalence in Denmark -an estimate based on multiple national registers BMC INFECTIOUS DISEASES, 12 >DOI >Link

Hay G, Gannon M, MacDougall J, Eastwood C, Williams K, Millar T. 2010. Opiate and crack cocaine use: A new understanding of prevalence DRUGS-EDUCATION PREVENTION AND POLICY, 17 :135-147 >DOI >Link

Bird SM, Hutchinson SJ, Hay G, King R. 2010. Missing targets on drugs-related deaths, and a Scottish paradox INTERNATIONAL JOURNAL OF DRUG POLICY, 21 :155-159 >DOI >Link

King R, Bird SM, Hay G, Hutchinson SJ. 2009. Estimating current injectors in Scotland and their drug-related death rate by sex, region and age-group via Bayesian capture-recapture methods STATISTICAL METHODS IN MEDICAL RESEARCH, 18 :341-359 >DOI >Link

McKeganey N, Casey J, McGallagly J, Hay G. 2009. Heroin seizures and heroin use in Scotland JOURNAL OF SUBSTANCE USE, 14 :240-249 >DOI >Link

Hay G, Gannon M, MacDougall J, Eastwood C, Williams K, Millar T. 2009. Capture--recapture and anchored prevalence estimation of injecting drug users in England: national and regional estimates. Stat Methods Med Res, 18 :323-339 >DOI >Link

Millar T, Domingo-Salvany A, Eastwood C, Hay G. 2008. Glossary of terms relating to capture-recapture methods JOURNAL OF EPIDEMIOLOGY AND COMMUNITY HEALTH, 62 :677-681 >DOI >Link

Bloor M, Gannon M, Hay G, Jackson G, Leyland AH, McKeganey N. 2008. Contribution of problem drug users' deaths to excess mortality in Scotland: secondary analysis of cohort study. BMJ, 337 :a478 >DOI >Link

Uuskula A, Rajaleid K, Talu A, Abel K, Ruutel K, Hay G. 2007. Estimating injection drug use prevalence using state wide administrative data sources: Estonia, 2004 ADDICTION RESEARCH & THEORY, 15 :411-424 >DOI >Link

Mckeganey N, Neale J, Lloyds C, Hay G. 2007. Drugs in the future: A response to Frisher DRUGS-EDUCATION PREVENTION AND POLICY, 14 :467-470 >DOI >Link

Millar T, Gemmell I, Hay G, Heller RF, Donmall M. 2006. How well do trends in incidence of heroin use reflect hypothesised trends in prevalence of problem drug use in the North West of England? ADDICTION RESEARCH & THEORY, 14 :537-549 >DOI >Link

Hay G, Gannon M. 2006. Capture-recapture estimates of the local and national prevalence of problem drug use in Scotland INTERNATIONAL JOURNAL OF DRUG POLICY, 17 :203-210 >DOI >Link

King R, Bird SM, Brooks SP, Hutchinson SJ, Hay G. 2005. Prior information in behavioral capture-recapture methods: Demographic influences on drug injectors' propensity to be listed in data sources and their drug-related mortality AMERICAN JOURNAL OF EPIDEMIOLOGY, 162 :694-703 >DOI >Link

Gemmell I, Millar T, Hay G. 2004. Capture-recapture estimates of problem drug use and the use of simulation based confidence intervals in a stratified analysis JOURNAL OF EPIDEMIOLOGY AND COMMUNITY HEALTH, 58 :758-765 >DOI >Link

Ishoy T, Haastrup L, Hay G. 2004. Estimating the prevalence of problem opioid use in Copenhagen 1997-1998 DANISH MEDICAL BULLETIN, 51 :114-116 >Link

Hay G, Smit F. 2003. Estimating the number of drug injectors from needle exchange data ADDICTION RESEARCH & THEORY, 11 :235-243 >DOI >Link

Hickman M, Taylor C, Chatterjee A, Degenhardt L, Frischer M, Hay G, Tilling K, Wiessing L, Griffiths P, McKetin R. 2002. Estimating the prevalence of problematic drug use: A review of methods and their application Bulletin on Narcotics, 54 :15-32

Roy K, Hay G, Andragetti R, Taylor A, Goldberg D, Wiessing L. 2002. Monitoring hepatitis C virus infection among injecting drug users in the European Union: a review of the literature. Epidemiol Infect, 129 :577-585 >DOI >Link

Flavell JM, Hay G. 2001. Using capture-recapture methods to reconstruct the American population in London JOURNAL OF INTERDISCIPLINARY HISTORY, 32 :37-53 >DOI >Link

Hay G, McKeganey N. 2001. The attendance pattern of clients at a Scottish needle exchange. Addiction, 96 :259-266 >DOI >Link

Hay G. 2000. Capture-recapture estimates of drug misuse in urban and non-urban settings in the north east of Scotland. Addiction, 95 :1795-1803 >DOI >Link

Greenhalgh D, Hay G. 1997. Mathematical modelling of the spread of HIV/AIDS amongst injecting drug users. IMA J Math Appl Med Biol, 14 :11-38 >Link

McKeganey N, Forsyth A, Barnard M, Hay G. 1996. Designer drinks and drunkenness among schoolchildren - Reply BRITISH MEDICAL JOURNAL, 313 :1397-1398 >DOI >Link

Hay G, McKeganey N. 1996. Corrigendum: Estimating the prevalence of drug misuse in Dundee, Scotland: An application of capture-recapture methods (Journal of Epidemiology and Community Health (1996) 50 (469-473)) Journal of Epidemiology and Community Health, 50 :691

Hay G, McKeganey N. 1996. Estimating the prevalence of drug misuse in Dundee, Scotland: an application of capture-recapture methods. J Epidemiol Community Health, 50 :469-472 >DOI >Link

McKeganey N, Forsyth A, Barnard M, Hay G. 1996. Designer drinks and drunkenness amongst a sample of Scottish schoolchildren. BMJ, 313 :401 >DOI >Link

McKeganey N, Abel M, Hay G. 1996. Contrasting methods of collecting data on injectors' risk behaviour. AIDS Care, 8 :557-563 >DOI >Link

Hay G, Kraus L, Richardson C, Yagic I, Ilhan MN, Ay P, Karasahin F, Pinarci M, Tuncoglu T, Piontek D, Shulte B. Estimating high-risk cannabis and opiate use in Ankara, Istanbul and Izmir Drug and Alcohol Review, >DOI >Public Url


McKeganey N, Neale J, Lloyd C, Hay G. 2007. Sociology and substance use Drugs and the Future :359-387 9780123706249 >DOI

Hay G. 1998. Estimating the prevalence of substance misuse Bloor M, Wood F. Addictions and Problem Drug Use: Issues in Behaviour, Policy and Practice Jessica Kingsley. London 978-1-85302-438-2

Cartwright P, Templeton L, Hay G. Improving the response of services Valentine C. Aftermath: supporting families and individuals bereaved following a drug or alcohol-related death

Templeton L, McKell J, Velleman R, Hay G. The diversity of bereavement through substance use Valentine C. Aftermath: supporting families and individuals bereaved following a drug or alcohol-related death Routledge

Conference publication

Hay G. 1997. The selection from multiple data sources in epidemiological capture-recapture studies JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES D-THE STATISTICIAN, 16th Annual Conference on Applied Statistics in Ireland 46 :515-520 >DOI >Link

Engagement & Impact

External collaboration:, Centre for Death and Society University of Bath, Tony Jackson

External PGR examinations performed:

University of Manchester, PhD

Trinity College Dublin, PhD