Mortality among Hispanic drug users in Puerto Rico

This paper assesses mortality rate for a cohort of drug users in Puerto Rico compared with that of the Island's general population, examining causes of death and estimating relative risk of death. Date and cause of death were obtained from death certificates during 1998. Vital status was confirmed through contact with subjects, family, and friends. HIV/AIDS was the major cause of death (47.7%), followed by homicide (14.6%), and accidental poisoning (6.3%). Females had higher relative risk of death than males in all age categories. Not living with a sex partner and not receiving drug treatment were related to higher mortality due to HIV/AIDS. Drug injection was the only variable explaining relative risk of death due to overdose. Puerto Rico needs to continue developing programs to prevent HIV/AIDS among drug users. Special attention should be given to young women, who appear to be in greatest need of programs to prevent early mortality.

Prevalence and correlates of DSM-IV substance use disorders in Puerto Rico

We report the basic findings of a survey aimed at estimating rates of substance disorders in a probability sample of 4,709 household residents aged 15 to 64 years old. Lifetime use of alcohol was reported by 77.2, and 10.7 reported ever using illicit drugs. Overall, 14.7 of the sample met criteria for a lifetime substance disorder, and 4.9 for a past year disorder. The rates of lifetime disorders were 13.1 for alcohol and 4.1 for illicit drug. Past year abuse/dependence was 4.3 for alcohol and 1.3 for illicit drugs. Alcohol use disorders were associated with male gender, higher family annual income, being employed, and being married. Illicit drug use disorders were associated with male gender and younger age. Only 13.0 of respondents with a past year disorder reported using services for their disorder. A program of continuous monitoring of substance using disorders is critical to establishing and monitoring effective policies

The validity of drug use responses in a household survey in Puerto Rico: comparison of survey responses of cocaine and heroin use with hair tests.

BACKGROUND: Despite the widespread use of household surveys to assess the epidemiology of illicit drug use and abuse, there is very little information about the willingness of respondents to disclose their use of drugs in household studies outside the US. METHODS: As part of a household study of substance use disorders in Puerto Rico, we collected hair specimens from a sub-sample of 114 respondents. Hair specimens were screened using a radio immunoassay. Screened-positive specimens were confirmed using gas chromatography/mass spectrometry. RESULTS: Using hair-test results as the standard, specificity of self-reports was 98% or higher for both drugs. The sensitivity of all self-reports was low, although lifetime use reports had somewhat higher sensitivities. The sensitivity of self-reports of recent cocaine use was particularly low, 7.1%. The sensitivity of heroin use reports was somewhat higher, 33.3% for recent use and 66.7% for lifetime use. The estimate of recent cocaine use based on hair tests was 13.7 times the estimate generated from interview reports. For heroin use, the test-based estimate was 2.9 times the rate generated from the interview reports. A shift from the cut-off level of 0.2 ng/mg to 0.5 ng/mg had only a marginal improvement on validity, with sensitivity increasing from 7.1% to 11.1% for self-reported recent cocaine use. CONCLUSIONS: The results suggest that drug users, for the most part, are not willing to disclose their use of drugs in household surveys in Puerto Rico. Methods to increase the willingness of respondents to disclose their use of drugs are needed.

Between-city variation in frequency of injection among Puerto Rican injection drug users: East Harlem, New York, and Bayamon, Puerto Rico.

Frequency of injection has been consistently found to be higher among Puerto Rican Injection drug users (IDUs) than among other groups of IDUs. Several explanations have been suggested, but an empirical explanation has yet to be presented. This study compares the frequency of injection of Puerto Rican IDUs in East Harlem, New York, with that of IDUs in Bayamon, Puerto Rico. Study subjects comprised 521 Puerto Rican IDUs from East Harlem and 303 IDUs from Bayamon. The mean frequency of injection among IDUs in East Harlem was 2.8, the corresponding mean in Bayamon was 5.4. Younger IDUs reported a higher number of daily injection episodes than older IDUs, and the IDU group in Bayamon was 5 years younger than the group in East Harlem. The drug use variables accounted for a greater portion of the between-city difference than the demographic and psychosocial variables. Use of noninjected drugs, as well as the use of prescribed methadone, were found to be associated with a lower number of daily injections. Conversely, injection of cocaine, injection of cocaine mixed with heroin ("speedball"), and injection of larger amounts of drug solution were found to be associated with a higher number of daily injections.

Determinants of environmental tobacco smoke in a population of Puerto Rican children.

This study was designed to determine among various personal, socioeconomic, and environmental factors those which had the greatest influence on exposure to environmental tobacco smoke (ETS) in a population of children residing in a tropical environment and to compare these results with those obtained in the literature of tobacco exposed children in temperate climates. Urine specimens were collected from 606 healthy Puerto Rican children (2-12 years) living in an industrial area and analyzed for cotinine, a quantitative biomarker for exposure to ETS. Parents completed a questionnaire covering smoking habits and socioeconomic information. Seventy per cent of the children were reported to be exposed to ETS, 50% resulting from exposure to smoke from either or both parents. Major determinants to ETS exposure were found to be presence of smoker, number of smokers, identity of smoker, number of cigarettes smoked in the household and child age with the youngest children suffering twice the exposure of older children. Non-determinants were exposure to smoke other than from the parent, sex of the child, season of the year and several socioeconomic factors including civil and employment status of the mother, mother's age and educational background and whether food stamps were being received. Results of a multiple regression analysis showed that our predictors accounted for 40% of cotinine appearing in the urine. Reasons for this relatively low value may be due in part to precision of our analytic method and lower levels of ambient smoke in our population vs. others that reported higher R(2) values. Predictions from questionnaire information for high ETS exposure were not always the same as those indicated by urinary cotinine emphasizing that the bioindicator, which indicates the actual inhalation of ETS, is a better predictor of exposure than responses from a questionnaire.

Prevalence and correlates of DSM-IV substance use disorders in Puerto Rico.

We report the basic findings of a survey aimed at estimating rates of substance disorders in a probability sample of 4,709 household residents aged 15 to 64 years old. Lifetime use of alcohol was reported by 77.2%, and 10.7% reported ever using illicit drugs. Overall, 14.7% of the sample met criteria for a lifetime substance disorder, and 4.9% for a past year disorder. The rates of lifetime disorders were 13.1% for alcohol and 4.1% for illicit drug. Past year abuse/dependence was 4.3% for alcohol and 1.3% for illicit drugs. Alcohol use disorders were associated with male gender, higher family annual income, being employed, and being married. Illicit drug use disorders were associated with male gender and younger age. Only 13.0% of respondents with a past year disorder reported using services for their disorder. A program of continuous monitoring of substance using disorders is critical to establishing and monitoring effective policies.

Factors associated with changes in sex behaviour among drug users in Puerto Rico.

Despite available strategies to prevent sex risk behaviours in Puerto Rico, heterosexual transmission of HIV continues to increase. Since 1990, heterosexual contact has been the fastest growing infection risk category among the island's general population, and the primary transmission route for women and children. To understand change in sex risk behaviours and factors related to change, 911 drug injectors and 359 crack smokers were recruited from the San Juan metropolitan area following a stratified cluster design. This study comprised a total of 1,004 (79.1%) drug users who were assessed at follow-up. Abstinence from sex behaviour increased from 54.6% to 61.1% (p < 0.01), use of condoms during vaginal sex also increased from 26.4% to 36.9% (p < 0.01). In multivariate analysis, significant predictors of abstinence were gender, injection drug use, HIV seropositivity and not having a steady partner. Predictors of using condoms during vaginal sex were HIV seropositivity, STD diagnosis and participation in an HIV preventive programme. These findings indicate that additional HIV preventive efforts are needed to reduce sex risk behaviours among drug users who have a steady sex partner, as well as among drug users who are HIV-negative.

PIP: Factors associated with changes in HIV risk behaviors were investigated in a prospective study of 911 injecting drug users and 359 crack smokers recruited on the basis of a stratified cluster design in metropolitan San Juan, Puerto Rico, in 1992-93. The findings presented in this paper are based on the 1004 drug users (79.1%) who were available for a follow-up interview 6 months after the baseline interview. Respondents were randomly assigned to receive a standard HIV prevention intervention (pretest counseling, optional HIV testing, and provision of HIV results) or the standard intervention plus a site-specific enhanced intervention entailing access to condoms and needle hygiene equipment, development of a personal risk reduction plan and training in the skills required to implement it, and ongoing contact with outreach workers. Overall, abstinence from sexual behavior increased from 54.6% at baseline to 61.1% at follow-up (p 0.01) while condom use during vaginal sex rose from 26.4% to 36.9% (p 0.01). In multivariate analysis, significant predictors of abstinence were male gender, injecting drug use, a positive HIV test at baseline, and not having a steady partner. Significant predictors of condom use were HIV seropositivity and a sexually transmitted disease diagnosis. Participation in the enhanced compared to the standard HIV prevention program was associated with an odds ratio of 1.29 (95% confidence interval, 0.95-1.74) for abstinence and 1.97 (95% confidence interval, 1.18-3.29) for condom use in vaginal sex.

Risk behaviors, HIV seropositivity, and tuberculosis infection in injecting drug users who operate shooting galleries in Puerto Rico.

This study was designed to assess HIV risk behaviors, HIV seroprevalence, and tuberculosis (TB) infection in shooting gallery managers in Puerto Rico. The subjects were 464 injection drug users (IDUs), of whom 12.5% reported managing shooting galleries. The median frequency of drug injection was higher in shooting gallery managers than in nonmanagers. A trend was observed for purified protein derivative (PPD) reactivity to increase according to the length of time spent as a gallery manager, but this trend was not statistically significant. However, anergy rates increased significantly with increase in the number of months spent as shooting gallery manager (p = .021). Multivariate analyses showed that IDUs reporting shooting gallery management experience of > or = 25 months were more likely to be infected with HIV. Prevention programs need to emphasize strategies to protect the health of shooting gallery clients and, in particular, shooting gallery managers. Additional studies are required to determine effective strategies for reducing the risk of HIV and TB infection in shooting galleries.

PIP: Little information is currently available on the health status of individuals who manage the settings in which drug injection-related behaviors occur. The present study investigated HIV risk behaviors, HIV seroprevalence, and tuberculosis infection among 464 injecting drug users recruited from areas in San Juan, Puerto Rico, known to have high levels of drug activity. 58 respondents (12.5%) reported having been a shooting gallery manager, for a median duration of 18 months. Managers were more likely to be female, over 35 years of age, not married, homeless, to inject only cocaine, to inject more frequently, to have a history of incarceration, and to report disability than drug users who were not managers. No differences in rates of HIV, tuberculosis, or anergy existed between managers with 1-24 months of management experience and nonmanagers. However, gallery managers with 25 or more months of experience were nearly 3 times more likely to be infected with HIV, nearly 2 times more likely to be anergic, and 2.5 times more likely to have tuberculosis than nonmanagers. 41% of nonmanagers, 48% of managers with 1-24 months of experience, and 71% of those who had been managers for 25 months or more were HIV-seropositive. The compromised health status of long-term shooting gallery managers underscores the need for public health interventions to interrupt the spread of sexually transmitted diseases, HIV, and tuberculosis in this high-risk setting.

Exposure of Puerto Rican children to environmental tobacco smoke.

BACKGROUND: Many studies of environmental tobacco smoke (ETS) have been conducted in northern, industrialized countries. As yet, however, no studies have been carried out on ETS exposure with nonsmokers living in tropical environments. METHODS: Urine specimens were collected from 175 healthy Puerto Rican children (2-11 years) living in an industrial area and were analyzed for cotinine, a quantitative biomarker for exposure to ETS. Their parents completed a questionnaire covering smoking habits. RESULTS: Seventy percent of children were exposed to ETS. Quantitatively, exposure to smoke in households consuming more than 1 pack per day (ppd) caused a doubling of cotinine excretion compared with households consuming less than 1 ppd. Smoke from mothers made the greatest contribution to cotinine, followed by smoke from fathers, with smoke from other persons having no effect. Degree of exposure was inversely related to age of the child. CONCLUSIONS: Young children (2-4 years) were detected to have significantly greater exposure to ETS than older children (5-11 years) and in the younger group the effect seemed to be from the mother's smoking much more than the father's, with other persons contributing negligible amounts. This suggests an obvious strategy for prevention of exposure to ETS in young children.

Behavioral effects of receiving HIV test results among injecting drug users in Puerto Rico.

OBJECTIVES: To examine the influence of knowledge of HIV serostatus on changes in risk behaviors among injecting drug users (IDU). PROCEDURES: IDU were recruited through sampling conducted at street drug-selling areas. Of 374 participants, 88.8% consented to be HIV tested and returned for their test results, and 73.5% were relocated and interviewed 6 months later. RESULTS: Of the 176 IDU who reported a seronegative test result prior to baseline, 29 tested seropositive at baseline. No significant differences were found between HIV-positive and HIV-negative IDU in needle risk behaviors. HIV-positive IDU were significantly less likely to report being sexually active [odds ratio (OR), 0.41 : 95% confidence interval (CI), 0.22-0.75] and more likely to use condoms during vaginal (OR, 4.43; 95% CI, 1.48-13.29) and oral sex (OR, 6.67; 95% CI, 1.42-31.33). CONCLUSION: The findings of this study show the importance of encouraging IDU to undergo periodic retesting. HIV testing could have an important role in reducing heterosexual transmission from IDU.

Risk factors for shooting gallery use among drug injectors in Puerto Rico.

Needle sharing is one of the principal risk behaviors leading to HIV transmission among injection drug users (IDUs). Shooting galleries, a social context where IDUs rent, share, and borrow needles, are locations usually found near drug markets. This study, which interviewed 1,700 IDUs from May 1989 to June 1990, assesses sociodemographic characteristics and HIV risk behaviors among shooting gallery users in Puerto Rico. Multivariate analyses showed that shooting gallery use is associated with speedball (a concoction of heroin and cocaine) injection, income from illegal activities and previous drug treatment. Shooting gallery users were more likely to rent, share, and borrow needles, and less likely to always use bleach and water to clean needles. Strategies to reduce shooting gallery use among drug injectors are discussed.

Risk factors for shooting gallery use among drug injectors in Puerto Rico

Needle sharing is one of the principal risk behaviors leading to HIV transmission among injection drug users (IDUs). Shooting galleries, a social context where IDUs rent, share, and borrow needles, are locations usually found near drug markets. This study, which interviewed 1,700 IDUs from May 1989 to June 1990, assesses sociodemographic characteristics and HIV risk behaviors among shooting gallery users in Puerto Rico. Multivariate analyses showed that shooting gallery use is associated with speedball (a concoction of heroin and cocaine) injection, income from illegal activities and previous drug treatment. Shooting gallery users were more likely to rent, share, and borrow needles, and less likely to always use bleach and water to clean needles. Strategies to reduce shooting gallery use among drug injectors are discussed

Formulae and tables for the determination of sample sizes and power in clinical trials for testing differences in proportions for the two-sample design: a review.

This paper is a compendium of exact and asymptotic formulae and tables for estimating the sample size in a clinical trial with two treatment groups and a dichotomous outcome. The paper provides separate formulae for equal and unequal treatment group sizes, formulae for the calculation of power given the sample size, and complete references for all formulae and tables cited.

Formulas and tables for the determination of sample sizes and power in clinical trials for testing differences in proportions for the matched pair design: a review.

This paper is a compendium of exact and asymptotic formulas and tables for calculating the sample size in a clinical trial for a matched-pair design involving a dichotomous outcome. Formulas for calculating power given the sample size are also given.

Prospective effects of perceived risk of developing HIV/AIDS on risk behaviors among injection drug users in Puerto Rico.

The relationship between perceived risk of developing AIDS and subsequent behavioral risk status is estimated for 1740 Puerto Rican injection drug users (IDUs). Prospective behavioral effects were examined comparing data collected at two intervals approximately 6 months apart. We estimated the association between perceived risk at baseline and risky behaviors at follow-up with unadjusted odds ratios. We confirmed the results with adjusted odds ratios using logistic regressions which included baseline risk status as well as socio-demographic and health status covariates. The analyses showed that having a high HIV/AIDS risk perception was related to subsequent sharing of needles, injection of drugs in shooting galleries and sharing of cookers. None of the tests between risk perception and sex risk behaviors showed a significance association. Increasing IDUs' perceived vulnerability to HIV/AIDS might not be effective in helping reduce HIV risk behaviors. IDUs perceiving themselves to be at high risk of AIDS might believe there is little they can do to reverse the consequences of risky behavior.

Effects of a community outreach program in HIV risk behaviors among injection drug users in San Juan, Puerto Rico: an analysis of trends.

This report assesses the effects of a community outreach program in reducing HIV risk behaviors among injection drug users (IDUs) in San Juan, Puerto Rico. Participants were 1,113 IDUs, 88.3% of whom were also assessed at post-intervention. The analytic strategy consisted in modeling pre- and post-intervention trends in risk behavior levels from successive cohorts of IDUs. The trend analyses showed that secular trends, unrelated to the direct effects of the outreach intervention, accounted for significant portions of the reported risk reductions. Nevertheless, the post-intervention trends in the shared use of cookers and in needle bleaching showed shifts that could not be accounted for by the modeled secular trends. The outreach intervention appears to have had significant but partial effects on the behavioral risks associated to drug injection and no effect on sexual behaviors. The strengths and weaknesses of time-trend analyses for evaluating community HIV-prevention programs lacking experimental designs are discussed.

On analysis of epidemiological data involving a 2 x 2 contingency table: an overview of Fisher's exact test and Yates' correction for continuity.

Fisher's exact test and Pearson's chi-square with continuity correction are frequently employed in the analysis of epidemiological data involving a 2 x 2 contingency table. This paper reviews the concepts and controversies underlying these procedures and discusses their appropriateness and adequacies in analyzing such data. Other related procedures such as unconditional exact tests and randomized and mid-p tests including some generalizations to a r x c table are also briefly reviewed.

A note on confidence intervals for the hypergeometric parameter in analyzing biomedical data.

Some methods of constructing confidence intervals for the probability of success in a hypergeometric distribution are described and illustrated with examples. To assist the readers in implementing the procedures, pertinent information on special tables and computer programs is provided that can be readily employed with little or no additional computation.

Human immunodeficiency virus infection and risk behaviors among injection drug users in four Puerto Rican communities.

This study compares the prevalence of human immunodeficiency virus (HIV) infection and HIV risk behaviors among 1,702 injection drug users (IDUs) recruited within four catchment areas in metropolitan San Juan (79.9% male and 20.1% female). To assess the impact of different antecedent variables on intercommunity risk differences, we constructed separate logistic regression models for each one of the catchment areas in the analysis. Old San Juan/Santurce has the highest rate of HIV seropositivity. Furthermore, Old San Juan/Santurce IDUs were more likely to have had incarceration experience, to report using drugs only by injection, and to have been injecting drugs for 16 years or more. Also, this group was more likely to report practicing prostitution and to have been diagnosed with sexually transmitted diseases (STDs) than their peers from the other sites. The need of preventive programs in specific communities within metropolitan urban areas is discussed.

Incarceration history as a risk factor for HIV infection among Puerto Rican injection drug users.

This study assesses factors associated with incarceration history and HIV seropositivity among 1,700 out-of-treatment drug injectors recruited in Puerto Rico between 1989-1990 from health care centers, emergency rooms, copping areas, shooting galleries, bars, billiard rooms and street corners. Analysis links incarceration history with criminal involvement and chronic drug use. After controlling for sociodemographics and previously reported correlates of HIV status, regression analysis shows incarceration history significantly relates to HIV status. The only predictor of incarceration history not related to HIV status was illegal activity as a major source of income. Analysis emphasizes HIV prevention programs within the penal system.