Psychosocial considerations for the prevention of HIV infection in injecting drug users

In this article, the authors discuss a study that investigated the meaning that injecting drug users attribute to risk behaviors linked to HIV transmission, especially through the use of nonsterile syringes or the failure to use condoms. To do this, social discourses with respect to the prevention of HIV infection are evaluated. The discussion focuses on how these discourses affect the daily practices of heroin users, practices that in turn influence discourses. Ethnography was used to observe 78 heroin users and 35 people following a methadone treatment program. Observation was carried out in a central district of Barcelona, Spain, with a low socioeconomic level. The results are a useful starting point for generating strategies aimed at preventing HIV transmission among this population on personal, community, and sociostructural levels.

Analytical considerations in the use of capture-recapture to estimate prevalence: case studies of the estimation of opiate use in the metropolitan area of Barcelona, Spain

Capture-recapture, an indirect method widely used to estimate undetected populations, has been criticized because it causes problems due to a lack of compliance with several important assumptions and model selection strategies. This paper expands on the problems encountered when applying this methodology to drug abuse estimations, specifically the prevalence of opiate use in the metropolitan area of Barcelona, Spain, in 1993. Three samples of opiate users (from hospital emergency rooms, treatment centers, and prisons) were available in the area studied; an additional sample (mortality data) was analyzed for the city of Barcelona. Log-linear models that provided a good fit were considered, to which further model selection strategies were applied. A total of 3,207 unique individuals aged 15-44 years were identified in the three samples from the greater Barcelona area; the mortality sample from the city of Barcelona contained an additional 83 individuals. Heterogeneity was observed in different age, sex, and residence area subgroups. Population estimates differed widely according to the log-linear model chosen. Minimum Akaike's information criterion model and saturated model estimates were used to produce population prevalence rates. The main problems the authors encountered in this study were related to population definition, source heterogeneity, and assessment of an adequate model, a problem associated with sample size.

[Information on opiate and cocaine consumption in the emergency room clinical records: validity and reliability]

BACKGROUND

Data on drug consumption obtained from emergency room clinical records have been used for various epidemiological purposes. However the validity and reliability of these data remain unknown. This paper assesses the reliability and validity of an Emergency Room Toxicological Register (HMR) which has collected information on drug misuse from emergency room clinical records since 1979, and examines the implications for epidemiological applications.

SUBJECTS AND METHODS

An Emergency Room Survey (ERS) was carried out in a Barcelona Hospital including opiate or cocaine users identified by the physician and a systematic sample of other patients age 15 to 49 years old. Data on clinical records of interviewed patients were also reviewed. Episodes from identified drug users (686) and HMR (676) for the same study period were linked and validity and reliability were analyzed.

RESULTS

Sensitivity ranged between 63 and 86%, and specificity was 98%, Kappa index higher than 0.72 and intraclass correlation coefficient was 0.99.

CONCLUSIONS

Information about drug users included in emergency room clinical records proved to be valid as an information system for drug use surveillance. However data about patterns of less heavy users, as cocaine use, are underreported.

Use of capture-recapture to estimate the prevalence of opiate addiction in Barcelona, Spain, 1989

It is difficult to obtain accurate prevalence estimates of opiate addiction with direct methods. The capture-recapture method has been used to estimate the prevalence of hidden populations, including opiate addicts. In this study, we applied capture-recapture, including log-linear modeling, to estimate the prevalence of opiate addicts in Barcelona, Spain. Anonymous identification data from three 1989 sources (hospital emergency rooms, treatment admissions, and heroin overdose deaths) in Barcelona were used to obtain population samples. For prevalence estimation, two strategies were followed: 1) emergency room data only, divided into trimesters; and 2) all three sources used simultaneously. Estimates based only on emergency room data were lower than estimates obtained by the simultaneous analysis of all three data sources; the latter estimates gave narrower confidence intervals (6,324-7,414 addicts), giving a prevalence for Barcelona in 1989 of between 8.5 and 9.9 opiate addicts per 1,000 residents aged 15-44 years. The estimated prevalence varied by sex and age group and was highest in males aged 15-29 years (between 17.1 and 21.2). At least 42% had contacted one or more of the services studied, although only one in seven had been admitted for treatment during 1989. Capture-recapture is the election method for prevalence estimation when direct methods are not feasible.

Opiates: prevalence and demographic factors

This paper focuses on the prevalence and profile of opiate use, primarily heroin, in the United States and Europe. Methods include representative population surveys, which understate prevalence, and targeted approaches, which reflect more problematic use. In the United States and Europe, the lifetime prevalence of opiate use reported in surveys remained stable over the 1980s (around 1%), though young adults report higher rates. Estimates for the early 1990s suggest that the prevalence of problematic heroin use in the United States was double the average for western Europe. However, in a few European countries prevalence is now approaching that of the United States. Rates in major cities are considerably higher, especially in the north-east and south-west of the United States. Higher prevalence is often, although not always, associated with socio-economic deprivation. An important trend away from injecting is observed, notably in some European countries. Heroin availability and use, as well as serious heroin-related consequences, are increasing again in many European countries after an apparent pause in the mid-1980s. They are also increasing in parts of the United States. Heroin remains a public health priority, especially among vulnerable populations, including young people in central and eastern Europe.

Opiate and cocaine consumers attending Barcelona emergency rooms: a one year survey (1989)

Due to the limitations of standard epidemiological methods, indirect indicators have often been used to describe the characteristics of drug abusing populations and to assess prevalence trends in illegal drug use. In Barcelona (Spain), a study of emergency room (ER) attendance was carried out to describe the population of opiate/cocaine consumers across the whole city who use this service. Three thousand four hundred and five consumers of opiates and/or cocaine, aged 15-44 years, who attended ERs during 1989, were identified. They accounted for 6807 episodes in the hospitals surveyed. Their mean age was 26 years, men (73%) being 1 year older than women (25.2 years). The drug of abuse was specified in the clinical records of 60% of individuals, heroin being the most frequently specified (56%). The main reason for attendance was 'other medical condition' (OMC) (55% of episodes), followed by withdrawal (34%) and overdoses (6%). Seventy-one percent of individuals were residents of Barcelona city, yielding a rate of 3.2 opiate/cocaine consumers attending ERs per thousand Barcelona residents aged 15-44. The geographical distribution of the rates in the city showed a very large difference between districts, the most deprived ones having a higher rate of consumers attending ERs. ER data can provide valuable insights into the nature and dimensions of drug abuse problems.

Current situation relating to drug abuse assessment in European countries

An increasing abuse of drugs among young people emerged in northwestern Europe during the late 1960s and early 1970s. Since the mid-1970s, the two most important trends have been the substantial increase in heroin abuse in most countries and increasing drug abuse in southern and eastern European countries that had relatively little previous experience with illicit drug use. Drug abuse is assessed using routine statistics, which are available but unreliable, or special epidemiological studies, which are more reliable but also more expensive. There is a need for more systematic and centralized monitoring of routine data from both treatment and enforcement sources; improved co-operation in such activities between European countries would enhance the value and utility of epidemiological work. Common criteria and definitions, as well as data-gathering instruments, need to be adopted so that data on drug abuse will be more comparable. The ways and means through which countries exchange knowledge and experience gained in drug abuse assessment need to be improved.

Evaluation of heroin maintenance in controlled trial

Ninety-six confirmed heroin addicts requesting a heroin maintenance prescription were randomly allocated to treatment with injectable heroin or oral methadone. Progress was monitored throughout the next 12 months by research workers operating independently of the clinic. Heroin can be seen as maintaining the status quo, with the majority continuing to inject heroin regularly and to supplement their maintenance prescription from other sources; it was associated with a continuing intermediate level of involvement with the drug subculture and criminal activity. Refusal to prescribe heroin while offering oral methadone constituted a more confrontational response and resulted in a higher abstinence rate, but also a greater dependence on illegal sources of drugs for these who continued to inject. Those offered oral methadone tended to polarize toward high or low categories of illegal drug use and involvement with the drug subculture, and were more likely to be arrested during the 12-month follow-up. There was no difference between the two groups in terms of employment, health, or consumption of nonopiate drugs. Refusal to prescribe heroin resulted in a significantly greater drop out from regular treatment.