Prevalence of drug use before and during imprisonment in seven European countries (2014-2018).

Substance use is a global phenomenon that is particularly affecting the prison population. This study aimed to describe the prevalence of drug use among people in prison before and during incarceration in seven European countries and to compare it with the prevalence in the general population. Individual data collection was carried out between 2014 and 2018 with a model European Questionnaire on Drug Use among people in prison. A total of 12,918 people living in prison filled in the survey. People in prison report higher level of drug use when compared with the general population and the use of drug inside prison exist, although at lower levels when compared with predetention. Prisons can represent a point of access to engage individuals who use drugs in interventions that address drug use and risk factors related to both drug use and imprisonment.

Prevalence of HCV among people who inject drugs in Brussels-a respondent-driven sampling survey.

BACKGROUND: In Belgium, people who inject drugs (PWID) are at a high risk of being infected by hepatitis C (HCV) as injecting drug use is the main mode for transmission of HCV in Europe. Estimates about the number of people living with HCV in Belgium are rare and even less is known about the prevalence of HCV among PWID. METHOD: Between 1 February 2019 and 26 April 2019, PWID and high-risk opiate users (HROU) were recruited in Brussels through respondent-driven sampling (RDS). They were invited to a questionnaire and underwent a rapid HCV test. RESULTS: A total of 253 respondents participated in the study, of which 168 were PWID and 238 were HROU, with 153 respondents belonging to both categories. The overall unweighted sample average for HCV antibodies was 41.1%. The weighted population estimates were 43.7% (95% CI 30.6-56.8%) for RDS-II and 43.4% (95% CI 28.9-58.0%) for RDS-SS. CONCLUSIONS: This prevalence is lower than the prevalence estimates reported elsewhere in Europe. However, the data still suggest that serious efforts are needed to reach the goal set by the WHO to reduce HCV by 2030 with 90%.

Prevalence of chronic HCV infection in EU/EEA countries in 2019 using multiparameter evidence synthesis.

Background: Epidemiological data are crucial to monitoring progress towards the 2030 Hepatitis C Virus (HCV) elimination targets. Our aim was to estimate the prevalence of chronic HCV infection (cHCV) in the European Union (EU)/European Economic Area (EEA) countries in 2019. Methods: Multi-parameter evidence synthesis (MPES) was used to produce national estimates of cHCV defined as: π = πrecρrec + πexρex + πnonρnon; πrec, πex, and πnon represent cHCV prevalence among recent people who inject drugs (PWID), ex-PWID, and non-PWID, respectively, while ρrec, ρex, and ρnon represent the proportions of these groups in the population. Information sources included the European Centre for Disease Prevention and Control (ECDC) national operational contact points (NCPs) and prevalence database, the European Monitoring Centre for Drugs and Drug Addiction databases, and the published literature. Findings: The cHCV prevalence in 29 of 30 EU/EEA countries in 2019 was 0.50% [95% Credible Interval (CrI): 0.46%, 0.55%]. The highest cHCV prevalence was observed in the eastern EU/EEA (0.88%; 95% CrI: 0.81%, 0.94%). At least 35.76% (95% CrI: 33.07%, 38.60%) of the overall cHCV prevalence in EU/EEA countries was associated with injecting drugs. Interpretation: Using MPES and collaborating with ECDC NCPs, we estimated the prevalence of cHCV in the EU/EEA to be low. Some areas experience higher cHCV prevalence while a third of prevalent cHCV infections was attributed to PWID. Further efforts are needed to scale up prevention measures and the diagnosis and treatment of infected individuals, especially in the east of the EU/EEA and among PWID. Funding: ECDC.

Dependence-Robust Confidence Intervals for Capture-Recapture Surveys.

Capture-recapture (CRC) surveys are used to estimate the size of a population whose members cannot be enumerated directly. CRC surveys have been used to estimate the number of Coronavirus Disease 2019 (COVID-19) infections, people who use drugs, sex workers, conflict casualties, and trafficking victims. When k-capture samples are obtained, counts of unit captures in subsets of samples are represented naturally by a 2k contingency table in which one element-the number of individuals appearing in none of the samples-remains unobserved. In the absence of additional assumptions, the population size is not identifiable (i.e., point identified). Stringent assumptions about the dependence between samples are often used to achieve point identification. However, real-world CRC surveys often use convenience samples in which the assumed dependence cannot be guaranteed, and population size estimates under these assumptions may lack empirical credibility. In this work, we apply the theory of partial identification to show that weak assumptions or qualitative knowledge about the nature of dependence between samples can be used to characterize a nontrivial confidence set for the true population size. We construct confidence sets under bounds on pairwise capture probabilities using two methods: test inversion bootstrap confidence intervals and profile likelihood confidence intervals. Simulation results demonstrate well-calibrated confidence sets for each method. In an extensive real-world study, we apply the new methodology to the problem of using heterogeneous survey data to estimate the number of people who inject drugs in Brussels, Belgium.

Use of health care services by people with substance use disorders in Belgium: a register-based cohort study.

BACKGROUND: The objective of the study was to describe the frequencies of health-care utilization by people with substance use disorder (SUD), including contacts with general practitioners (GP), psychiatrists, emergency departments (ED) and hospital admissions and to compare this frequency to the general population. METHODS: Data from the national register of people who were in treatment for SUD between 2011 and 2014 was linked to health care data from the Belgian health insurance (N = 30,905). Four comparators were matched on age, sex and place of residence to each subject in treatment for SUD (N = 123,620). Cases were further divided in five mutually exclusive categories based on the main SUD (opiates, crack/cocaine, stimulants, cannabis and alcohol). We calculated the average number of contacts with GP, psychiatrists and ED, and hospital admissions per person over a ten year period (2008-2017), computed descriptive statistics for each of the SUD and used negative binomial regression models to compare cases and comparators. RESULTS: Over the ten-year period, people in treatment for SUD overall had on average 60 GP contacts, 3.9 psychiatrist contacts, 7.8 visits to the ED, and 16 hospital admissions. Rate ratios, comparing cases and corresponding comparators, showed that people in treatment for SUD had on average 1.9 more contacts with a GP (95 % CI 1.9-2.0), 7.4 more contacts with a psychiatrist (95 % CI 7.0-7.7), 4.2 more ED visits (95 % CI 4.2-4.3), and 6.4 more hospital admissions (95 % CI 6.3-6.5). CONCLUSIONS: The use of health services for people with SUD is between almost two (GP) and seven times (psychiatrist) higher than for comparators. People in treatment for alcohol use disorders use health care services more frequently than people in treatment for other SUD. The use of health services remained stable in the five years before and after the moment people with SUD entered into treatment for SUD. The higher use of primary health care services by people with SUD might indicate that they have higher health care needs than comparators.

Estimates of people who injected drugs within the last 12 months in Belgium based on a capture-recapture and multiplier method.

BACKGROUND: For Belgium, available estimates of the number of people who inject drugs (PWID) are based on data from more than fifteen years ago and apply only to those who report ever injecting drugs. As a result, no reliable baseline data exist to determine the scale of services for PWID. METHODS: We obtained pseudo-anonymized identifier information from treatment and harm reduction service providers and a fieldwork study between February and April 2019 in Brussels. We estimated the number of PWID, defined as people who injected within the last 12 months, in Brussels using capture-recapture (CRC) methodology. To obtain national estimates, we scaled the proportion of PWID in Brussels to the total number of this population in Belgium based on two existing drug treatment registers, which were then multiplied with the result of the CRC. RESULTS: The total population of PWID is estimated to be 703 (95 %CI 538-935) for Brussels and between 6620 (95 %CI 4711 - 8576) and 7018 (95 %CI 4794 - 9527) for Belgium. CONCLUSIONS: These estimates provide crucial information to ensure that services to PWID are adequately maintained. They clearly indicate the need to maximize efforts to achieve the targets set by WHO for 2030 on the provision of 300 sterile needles and syringes per PWID per year, a 90 % reduction of new HCV infections, and a 65 % reduction of liver-related mortality.

COVID-19 and people who use drugs: Impact of the pandemic on general anxiety and depressive disorders among adults in Belgium.

BACKGROUND: During previous pandemics people who use drugs (PWUD) were categorized among the most vulnerable. In the current study, firstly, we wanted to evaluate the impact of the COVID-19 crisis on the prevalence of anxiety and depressive disorders among PWUD. Furthermore, we wanted to compare the prevalence of these disorders with that of members from the general population who did not use drugs. METHODS: We used a matched cohort design based on two separate repeated cross-sectional online surveys (April and November 2020) among PWUD and the general population. Results of GAD-7 and PHQ-9 were used as outcome variables. We calculated absolute and relative risks for matched pairs for both affective disorders, and logistic regression to compare affective disorders over both waves for PWUD. RESULTS: In April, the prevalence of affective disorders was similar for PWUD and the general population. In November, the risks for anxiety disorders increased with 64% for PWUD compared to non-PWUD (RR = 1.64, 95%CI 1.42-1.88), whereas the risks for depressive disorders more than doubled (RR = 2.29, 95%CI 1.97-2.67). Having a job and being male were protective factors for PWUD for both anxiety and depressive disorders. LIMITATIONS: As this study used self-reported data, GAD-7 and PHQ-9 give an indication of the presence of anxiety and depression which might differ from a clinician's judgement. CONCLUSIONS: PWUD might be disproportionally affected by COVID-19. Health care providers should be attentive to substance use as an indicator for increased risk of mental health problems.

Alternatives to prison for drug offenders in Belgium during the past decade.

OBJECTIVE: Imprisonment has a more pronounced criminogenic effect on drug offenders than on other types of offenders. Additionally, little research has been conducted on the practical application of drug-related alternatives to prison. Therefore, this study describes drug-related alternatives to prison in Belgium over a ten years' period since 2005. METHODS: The applied drug-related alternatives to prison ('probation', 'conditional release', 'mediation in criminal cases', 'community service' and 'electronic monitoring') were subject to a secondary data analysis of the database of the Houses of Justice. RESULTS: Men, the age group of 16-24 years old and Belgians are most sentenced to alternatives to prison. Nevertheless, 38% of women are guided towards 'probation' while 8% is 'mediated in criminal cases' compared to 30% and 5% of males respectively (p < .001). 26% of non-Belgians are involved in 'conditional release' and 'electronic monitoring' compared to 22% and 16% among Belgians (p < .001) respectively. With regards to age, 21% of the offenders older than 24 years are involved in 'electronic monitoring' compared to 6% among the offenders younger than 25 years (p < .001). CONCLUSIONS: The results highlight differences in punishment judgments by age, gender and nationality that continues to be indicative for perceived threat, danger and culpability of the offenders.

Treatment for substance use disorders: the Belgian Treatment Demand Indicator registration protocol.

BACKGROUND: Registration of patients with substance use disorders is of key importance to get insights and to study trends in patients characteristics and substance use patterns. The Treatment Demand Indicator (TDI) is gathering this information at European level since 2000. In Belgium, this registration started at national level in 2011 and an increasing number of facilities of different types are participating in this data collection since then. METHODS/DESIGN: This surveillance register collects information on every treatment episode started by patients for their substance use disorder. Information is collected on socio-demographic characteristics of the patient, treatment history and substance use patterns. Patients are identified uniquely using their national identification number in order identify multiple episodes followed by a same person. A large range of treatment facilities have the possibility to participate in this registration to allow a wide coverage of the population. DISCUSSION: The objective of the paper is to facilitate the use of data by authorities or researchers by correctly describing all aspects of the indicator. The case definition, the variables collected and the way data should be reported are of key importance to use and interpret the data correctly. An overview of the data registered in 2014 gives also an idea of the content of the database. The article also pictures the strengths and limitations of the register and foresees some future improvements.