Aims: This review provides an up‐to‐date curated source of information on alcohol, tobacco and illicit drug use and their associated mortality and burden of disease. Limitations in the data are also discussed, including how these can be addressed in the future.Methods: Online data sources were identified through expert review. Data were obtained mainly from the World Health Organization, United Nations Office on Drugs and Crime and Institute for Health Metrics and Evaluation.Results: In 2015, the estimated prevalence among the adult population was 18.4% for heavy episodic alcohol use (in the past 30 days); 15.2% for daily tobacco smoking; and 3.8, 0.77, 0.37 and 0.35% for past‐year cannabis, amphetamine, opioid and cocaine use, respectively. European regions had the highest prevalence of heavy episodic alcohol use and daily tobacco use. The age‐standardized prevalence of alcohol dependence was 843.2 per 100 000 people; for cannabis, opioids, amphetamines and cocaine dependence it was 259.3, 220.4, 86.0 and 52.5 per 100 000 people, respectively. High‐income North America region had among the highest rates of cannabis, opioid and cocaine dependence. Attributable disability‐adjusted life‐years (DALYs) were highest for tobacco smoking (170.9 million DALYs), followed by alcohol (85.0 million) and illicit drugs (27.8 million). Substance‐attributable mortality rates were highest for tobacco smoking (110.7 deaths per 100 000 people), followed by alcohol and illicit drugs (33.0 and 6.9 deaths per 100 000 people, respectively). Attributable age‐standardized mortality rates and DALYs for alcohol and illicit drugs were highest in eastern Europe; attributable age‐standardized tobacco mortality rates and DALYs were highest in Oceania.Conclusions: In 2015 alcohol use and tobacco smoking use between them cost the human population more than a quarter of a billion disability‐adjusted life years, with illicit drugs costing further tens of millions. Europeans suffered proportionately more, but in absolute terms the mortality rate was greatest in low‐ and middle‐income countries with large populations and where the quality of data was more limited. Better standardized and rigorous methods for data collection, collation and reporting are needed to assess more accurately the geographical and temporal trends in substance use and its disease burden.

Background and Aims: People who have recently injected drugs are a priority population in efforts to achieve hepatitis C virus (HCV) elimination. This study estimated the prevalence and number of people with recent injecting drug use living with HCV, and the proportion of people with recent injecting drug use among all people living with HCV infection at global, regional and country‐levels.Methods: Data from a global systematic review of injecting drug use and HCV antibody prevalence among people with recent (previous year) injecting drug use were used to estimate the prevalence and number of people with recent injecting drug use living with HCV. These data were combined with a systematic review of global HCV prevalence to estimate the proportion of people with recent injecting drug use among all people living with HCV.Results: There are an estimated 6.1 million [95% uncertainty interval (UI) = 3.4–9.2] people with recent injecting drug use aged 15–64 years living with HCV globally (39.2% viraemic prevalence; UI = 31.6–47.0), with the greatest numbers in East and Southeast Asia (1.5 million, UI = 1.0–2.1), eastern Europe (1.5 million, UI = 0.7–2.4) and North America (1.0 million, UI = 0.4–1.7). People with recent injecting drug use comprise an estimated 8.5% (UI = 4.6–13.1) of all HCV infections globally, with the greatest proportions in North America (30.5%, UI = 11.7–56.7), Latin America (22.0%, UI = 15.3–30.4) and eastern Europe (17.9%, UI = 8.2–30.9).Conclusions: Although, globally, 39.2% of people with recent injecting drug use are living with hepatitis C virus (HCV) and 8.5% of all HCV infections occur globally among people with recent injecting drug use, there is wide variation among countries and regions.

Background and Aims: Studies often rely upon self‐report and biological testing methods for measuring illicit drug use, although evidence for their agreement is limited to specific populations and self‐report instruments. We aimed to examine comprehensively the evidence for agreement between self‐reported and biologically measured illicit drug use among all major illicit drug classes, biological indicators, populations and settings.Methods: We systematically searched peer‐reviewed databases (Medline, Embase and PsycINFO) and grey literature. Included studies reported 2 × 2 table counts or agreement estimates comparing self‐reported and biologically measured use published up to March 2022. With biological results considered to be the reference standard and use of random‐effect regression models, we evaluated pooled estimates for overall agreement (primary outcome), sensitivity, specificity, false omission rates (proportion reporting no use that test positive) and false discovery rates (proportion reporting use that test negative) by drug class, potential consequences attached to self‐report (i.e. work, legal or treatment impacts) and time‐frame of use. Heterogeneity was assessed by inspecting forest plots.Results: From 7924 studies, we extracted data from 207 eligible studies. Overall agreement ranged from good to excellent (> 0.79). False omission rates were generally low, while false discovery rates varied by setting. Specificity was generally high but sensitivity varied by drug, sample type and setting. Self‐report in clinical trials and situations of no consequences was generally reliable. For urine, recent (i.e. past 1–4 days) self‐report produced lower sensitivity and false discovery rates than past month. Agreement was higher in studies that informed participants biological testing would occur (diagnostic odds ratio = 2.91, 95% confidence interval = 1.25–6.78). The main source of bias was biological assessments (51% studies).Conclusions: While there are limitations associated with self‐report and biological testing to measure illicit drug use, overall agreement between the two methods is high, suggesting both provide good measures of illicit drug use. Recommended methods of biological testing are more likely to provide reliable measures of recent use if there are problems with self‐disclosure.