Abstract
BACKGROUND: Globally, an estimated 15·6 million people inject drugs. We aimed to investigate global variation in the age profile of people who inject drugs (PWID), identify country-level factors associated with age of PWID, and assess the association between injecting drug use (IDU) in young people and rates of injecting and sexual risk behaviours at the country level.
METHODS: We derived data from a previously published global systematic review done in April, 2016 (and updated in June, 2017) on the percentage of young PWID, duration of IDU, average age of PWID, average age at IDU initiation, and the percentage of PWID reporting sexual and injecting risk behaviours. We also derived national development indicators from World Bank data. We estimated the percentage of young PWID for each country, using a random-effects meta-analysis (DerSimonian-Laird methodology) and generated pooled regional and global estimates for all indicators of IDU in young people. We used univariable and multivariable generalised linear models to test for associations between the age indicators and country urban population growth, youth unemployment percentage, the percentage of PWID who are female, the percentage of the general population aged 15-24 years, Gini coefficient, opioid substitution therapy coverage (per PWID per year), gross domestic product (GDP) per capita (US$1000), and sexual and injecting risk behaviours.
FINDINGS: In the original systematic review, data on age of PWID was reported in 741 studies across 93 countries. Globally, 25·3% (95% uncertainty interval [UI] 19·6-31·8) of PWID were aged 25 years or younger. The highest percentage of young PWID resided in eastern Europe (43·4%, 95% UI 39·4-47·4), and the lowest percentage resided in the Middle East and north Africa (6·9%, 5·1-8·8). At the country level, in multivariable analysis higher GDP was associated with longer median injecting duration (0·11 years per $1000 GDP increase, 95% CI 0·04-0·18; p=0·002), and older median age of PWID (0·13 years per $1000 increase, 0·06-0·20; p<0·0001). Urban population growth was associated with higher age at IDU initiation (1·40 years per annual percentage change, 0·41-2·40). No associations were identified between indicators of IDU in young people and youth unemployment, Gini coefficient, or opioid substitution therapy coverage provision at the country level. No associations were identified between injecting and sexual risk behaviours and age of PWID.
INTERPRETATION: Variation in the age profile of PWID was associated with GDP and urbanisation. Regions with the highest prevalence of young PWID (aged ≤25 years) had low coverage of interventions to prevent the spread of blood-borne viruses. Data quality highlights the need for improvements in monitoring of PWID populations.
FUNDING: Australian National Drug and Alcohol Research Centre, Australian National Health and Medical Research Council, Open Society Foundation, WHO, the Global Fund, UNAIDS, National Institute for Health Research Health Protection Research Unit for Evaluation of Interventions, Wellcome Trust.
| Original language | English |
|---|---|
| Pages (from-to) | e76-e91 |
| Number of pages | 16 |
| Journal | The Lancet. Global Health |
| Volume | 8 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 31 Jan 2020 |
| Externally published | Yes |
Bibliographical note
LAH reports grants from the Australian Government and Wellcome Trust during the conduct of the study. SL has received investigator-initiated untied educational grants from Indivior. AP reports grants from the WHO, Global Fund, UNAIDS, and the Australian Government Department of Health during the conduct of the study, and has received investigator-initiated untied educational grants from Mundipharma and Seqirus. LD reports investigator-initiated untied educational grants for studies of opioid medications in Australia from Indivior, Mundipharma, and Seqirus. MH reports personal fees from MSD and Gilead Sciences, outside the submitted work. JG is a consultant and advisor for and has received research grants from AbbVie, Cepheid, Gilead Sciences, and MSD. All other authors declare no competing interests.Acknowledgements
We thank the research assistants whoassisted with searches for and extraction of data from the eligible papers
in this review: Griselda Buckland and Harriet Townsend (National Drug
and Alcohol Research Centre, University of New South Wales), and
Diana Sergiienko (Ukrainian Institute of Public Health Policy). We also
thank the individuals who provided encouragement and support in
various ways throughout the conduct of this study, including circulating
requests for data, provision of in-country contacts and assistance with
locating data: Annette Verster, Vladimir Poznyak (WHO), Andre Noor,
Eleni Kalamara (European Monitoring Centre for Drugs and Drug
Addiction), Jinkou Zhao (the Global Fund), Keith Sabin (UNAIDS),
Catherine Cook, (Harm Reduction International), and Riku Lehtovuori,
and Gilberto Gerra (UN Office on Drugs and Crime). Assistance in
sourcing and verifying data was provided by many individuals from
government, non-government, and research organisations around the
world, for which we are thankful.
Funding
This study was partly funded by the Australian National Drug and Alcohol Research Centre (University of New South Wales). LAH is supported by a Sir Henry Wellcome Postdoctoral Fellowship from the Wellcome Trust. LD is supported by an Australian National Health and Medical Research Council (NHMRC) Senior Principal Research Fellowship. JL acknowledges funding from the Bill & Melinda Gates Foundation. The Kirby Institute is funded by the Australian Government Department of Health and Ageing. The views expressed in this publication are those of the authors and do not necessarily represent the position of the Australian Government. JG is supported by an NHMRC Career Development Fellowship. JS acknowledges funding from a PhD scholarship from the Engineering and Physical Sciences Research Council. AT has received PhD funding from the National Institute for Health Research (NIHR). MH and PV acknowledge support from NIHR Health Protection Research Unit in Evaluation of Interventions (HPRU EI) at the University of Bristol. MH is an NIHR senior investigator and acknowledges NIHR School of Public Health Research and the NIHR HPRU EI. PV acknowledges support from the NIHR HPRU in Blood Borne and Sexually Transmitted Infections at University College London and National Institute for Drug Abuse (grant number R01 DA037773–01A1).
Keywords
- Adolescent
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Female
- Global Health/statistics & numerical data
- Humans
- Male
- Middle Aged
- Prevalence
- Risk-Taking
- Substance Abuse, Intravenous/epidemiology
- Young Adult
