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Biomedical subjects

H Sahai

Publications and source records attributed to H Sahai.

At least 19 recordsLinked to original sources
PubMed1998

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.

AIDS-Related Opportunistic Infections↗
PubMed1998

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.

Adult↗
PubMed1996

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.

Binomial Distribution↗
PubMed1996

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.

Female↗
PubMed1996

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.

Adult↗
PubMed1995

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.

Acquired Immunodeficiency Syndrome↗
PubMed1995

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.

Biometry↗
PubMed1995

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.

Adult↗
PubMed1993

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.

Adult↗
PubMed1993

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.

Adult↗
PubMed1992

Behavioral risk factors and human immunodeficiency virus (HIV) prevalence among intravenous drug users in Puerto Rico.

This study reports on four empirical models likely to contribute to understanding the behaviors linked with human immunodeficiency virus (HIV) among intravenous drug users. The sample comprises 1,637 intravenous drug users recruited between May 1989 and June 1990 in San Juan, Puerto Rico. Adjusting for sociodemographics, four logistic regression models were constructed to assess the association of risk behaviors with HIV seropositivity. In model 1, the variables found to be significantly associated with HIV seropositivity were injecting four times a day, injection as the only route of consuming drugs, and years of injection. In model 2, the only risk behavior significantly associated with HIV seropositivity was injecting drugs in shooting galleries. In model 3, all sex risk variables failed to meet the adjusted level of significance. In model 4, pneumonia, hepatitis, and syphilis were significantly linked with HIV infection. In order to assess the individual effects of the significant variables in each one of the four models, a logistic regression analysis was performed simultaneously controlling for all of the variables. After adjustment for the Bonferroni correction, age group 25-34 years, injection as the only route of using drugs, number of years of injection, and syphilis were the only significant variables remaining.

Age Factors↗
PubMed1992

Changes in HIV risk behaviors among intravenous drug users in San Juan, Puerto Rico.

Strategies for reaching intravenous drug users (IVDUs) not in treatment and reducing risk behaviors are urgently needed to reduce the human immunodeficiency virus (HIV) epidemic. Of special concern is the need to detect which types of risk behaviors are more likely to change and which are resistant to change. The present paper analyzes changes occurring in HIV transmission risk behaviors among 778 IVDUs not in treatment, in the city of San Juan, Puerto Rico. Results show discontinuation rates of risk behaviors to be substantial. Discontinuation rates of injection equipment sharing practices varied from 33% in shared use of cookers to 74.2% in sharing needles with strangers. Drug injection and use of shooting galleries were also reduced, although to a lesser extent (8.5% and 19.3% respectively). Among protective behaviors, use of new needles was found to increase nearly twice as much as the use of bleach (20.6% vs. 11.3% respectively). The results suggest the need to understand the factors facilitating/inhibiting change in specific behaviors and the need to study the stability of these changes over longer periods of time.

Adult↗
PubMed1991

HIV risk and prior drug treatment among Puerto Rican intravenous drug users.

HIV transmission through sharing of drug injection paraphernalia is the single largest mode of infection in Puerto Rico. Of special concern to health professionals is the lack of information related to HIV risk behavior and lifestyles of IVDU's not in drug treatment. The paper analyzes the extent to which 862 currently active IVDU's in Puerto Rico had utilized drug treatment services and the differences between IVDU's with and without prior treatment history. Results show that two thirds of the IVDU's had been previously enrolled in drug treatment on an average of three times and a median per episode length of stay of 3 weeks. A step-wise discriminant analysis revealed that the number of years of drug injection previous incarceration, self-reported previous diagnoses of hepatitis and living with parents are relevant discriminating factors between treatment utilizers and non-utilizers. Policy implications of the results are also discussed.

Adult↗
PubMed1990

Some comments on teaching biostatistics in medical and health sciences.

The role of statistical methods is now well recognized in health sciences since these disciplines are concerned with the study of communities or populations where the principles of sampling and statistical inference are clearly applicable. However, many medical and health sciences teachers and students have been slower to perceive the need for knowledge of biostatistical methods, even though all aspects of medical diagnosis and prognosis are governed by the laws of probability. Some of them are still skeptical about the value and importance of biostatistical principles to their fields and raise questions about the meaning, content, and nature of biostatistics and relevance of its teaching to health sciences disciplines. The purpose of this essay is to address some of these issues with the hope to invoke comments and responses from other biostatistics instructors who have encountered similar predicaments in their teaching and consulting roles to health sciences students and professionals.

Biometry↗
PubMed1989

Relations of sociodemographic variables and cognitive ability: a comparative analysis of the cognitive scores of high school seniors.

This paper compares subgroups using cognitive scores from a test battery administered to high school seniors in the base year survey in 1980. The procedures used to select the sample were designed to yield a data base that can be statistically projected to represent the national population of about 3,040,000 high school seniors. Comparisons were performed to examine differences in cognitive scores by age, sex, race/ethnicity, socioeconomic status, and census region. Boys scored higher than girls on mathematics and visualization tests, but lower on the picture-number and mosaic comparison tests. Mean scores of the two sexes on the vocabulary and reading tests differed by less than 0.1 SD. Asian/Pacific Islanders had higher means than white students and other minority groups on the mathematics, mosaic comparisons, and visualization test, but their scores did not differ significantly from those of white students on the other three tests. Means for Hispanics were lower than those for white students but higher than those for black students, except on reading. Mean scores of Cubans exceeded those of Mexican Americans, Puerto Ricans or other Hispanics. A positive correlation 0.40 obtained between test scores and the socioeconomic status or education attained by the examinees' mothers. Students in New England had the highest means except on visualization for which the highest scores were in the West, followed in order by those in the Middle Atlantic, West North Central, East North Central, Pacific, Mountain, South Atlantic, East South Central, and West South Central regions.

Achievement↗