Estimating the burden of disease attributable to injecting drug use as a risk factor for HIV, hepatitis C, and hepatitis B: findings from the Global Burden of Disease Study 2013.
BACKGROUND
Previous estimates of the burden of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) among people who inject drugs have not included estimates of the burden attributable to the consequences of past injecting. We aimed to provide these estimates as part of the Global Burden of Disease (GBD) Study 2013.


METHODS
We modelled the burden of HBV and HCV (including cirrhosis and liver cancer burden) and HIV at the country, regional, and global level. We extracted United Nations data on the proportion of notified HIV cases by transmission route, and estimated the contribution of injecting drug use (IDU) to HBV and HCV disease burden by use of a cohort method that recalibrated individuals' history of IDU, and accumulated risk of HBV and HCV due to IDU. We estimated data on current IDU from a meta-analysis of HBV and HCV incidence among injecting drug users and country-level data on the incidence of HBV and HCV between 1990 and 2013. We calculated estimates of burden of disease through years of life lost (YLL), years of life lived with disability (YLD), deaths, and disability-adjusted life-years (DALYs), with 95% uncertainty intervals (UIs) calculated for each metric.


RESULTS
In 2013, an estimated 10·08 million DALYs were attributable to previous exposure to HIV, HBV, and HCV via IDU, a four-times increase since 1990. In total in 2013, IDU was estimated to cause 4·0% (2·82 million DALYs, 95% UI 2·4 million to 3·8 million) of DALYs due to HIV, 1·1% (216 000, 101 000-338 000) of DALYs due to HBV, and 39·1% (7·05 million, 5·88 million to 8·15 million) of DALYs due to HCV. IDU-attributable HIV burden was highest in low-to-middle-income countries, and IDU-attributable HCV burden was highest in high-income countries.


CONCLUSIONS
IDU is a major contributor to the global burden of disease. Effective interventions to prevent and treat these important causes of health burden need to be scaled up.


BACKGROUND
Bill & Melinda Gates Foundation and Australian National Health and Medical Research Council.
National Drug and Alcohol Research Centre, University of New South Wales Australia, Sydney, NSW, Australia. Electronic address: l.degenhardt@unsw.edu.au.
Louisa
L
Degenhardt
Policy and Evaluation Group, Queensland Centre for Mental Health Research, Brisbane, QLD, Australia; School of Population Health, University of Queensland, Brisbane, QLD, Australia.
Fiona
F
Charlson
Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Jeff
J
Stanaway
National Drug and Alcohol Research Centre, University of New South Wales Australia, Sydney, NSW, Australia.
Sarah
S
Larney
Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Lily T
LT
Alexander
School of Social and Community Medicine, University of Bristol, Bristol, UK.
Matthew
M
Hickman
Doherty Institute, University of Melbourne, Melbourne, VIC, Australia.
Benjamin
B
Cowie
Centre for Youth Substance Abuse Research, University of Queensland, Brisbane, QLD, Australia; National Addiction Centre, King's College London, London, UK.
Wayne D
WD
Hall
National Addiction Centre, King's College London, London, UK.
John
J
Strang
Policy and Evaluation Group, Queensland Centre for Mental Health Research, Brisbane, QLD, Australia; School of Population Health, University of Queensland, Brisbane, QLD, Australia.
Harvey
H
Whiteford
Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Theo
T
Vos
D017281:Cost of Illness; D000071219:Global Burden of Disease / Q000706:statistics & numerical data*; D014943:Global Health; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology*; D006509:Hepatitis B / Q000150:complications / Q000453:epidemiology*; D006526:Hepatitis C / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D008017:Life Expectancy; D019057:Quality-Adjusted Life Years; D012307:Risk Factors; D012737:Sex Factors; D015819:Substance Abuse, Intravenous