Patterns of alcohol and illicit substance use in the United States and Mexico. Substantive and methodologic issues in the cross-national analysis of alcohol and drug use data

This research examines prevalence of alcohol and illicit substance use in the United States and Mexico and associated socio-demographic characteristics. The sources of data for this study are public domain data from the U.S. National Household Survey of Drug Abuse, 1988 (n = 8814), and the Mexican National Survey of Addictions, 1988 (n = 12,579). In addition, this study discusses methodologic issues in cross-cultural and cross-national comparison of behavioral and epidemiologic data from population-based samples. The extent to which patterns of substance abuse vary among subgroups of the U.S. and Mexican populations is assessed, as well as the comparability and equivalence of measures of alcohol and drug use in these national samples.^ The prevalence of alcohol use was somewhat similar in the two countries for all three measures of use: lifetime, past year and past year heavy use, (85.0%, 68.1%, 39.6% and 72.6%, 47.7% and 45.8% for the U.S. and Mexico respectively). The use of illegal substances varied widely between countries, with U.S. respondents reporting significantly higher levels of use than their Mexican counterparts. For example, reported use of any illicit substance in lifetime and past year was 34.2%, 11.6 for the U.S., and 3.3% and 0.6% for Mexico. Despite these differences in prevalence, two demographic characteristics, gender and age, were important correlates of use in both countries. Men in both countries were more likely to report use of alcohol and illicit substances than women. Generally speaking, a greater proportion of respondents in both countries 18 years of age or older reported use of alcohol for all three measures than younger respondents; and a greater proportion of respondents between the ages of 18 and 34 years reported use of illicit substances during lifetime and past year than any other age group.^ Additional substantive research investigating population-based samples and at-risk subgroups is needed to understand the underlying mechanisms of these associations. Further development of cross-culturally meaningful survey methods is warranted to validate comparisons of substance use across countries and societies. ^

Illicit drug use, alcohol use and nicotine dependence as predictors of antiretroviral adherence in a sample of HIV positive smokers

Objective. Predictors of non-adherence to antiretroviral medications in a population of low-income, multiethnic, HIV-positive smokers were investigated. ^ Methods. A secondary analysis was conducted using baseline data collected from 326 patients currently prescribed antiretrovirals enrolled in a randomized clinical trial assessing smoking outcomes. Variables evaluated included demographics, stress, depression, nicotine dependence, illicit drug use and alcohol use. ^ Results. The average age of participants was 45.9 years (SD=7.6). The majority of participants were male (72.1%), Black (76.7%), reported sexual contact as the method of HIV exposure (heterosexual (43%) and MSM (27%)) and were antiretroviral adherent (60.4%). Results from unadjusted analyses indicated depression (OR=1.02; 95% CI=1.00-1.04), illicit drug use (OR=2.39; 95% CI=1.51-3.79) and alcohol consumption (OR=2.86; 95% CI=1.79-4.57) were associated with non-adherence. Multivariate analyses indicated nicotine dependence (OR=1.13; 95% CI=1.02-1.25), illicit drug use (OR=2.10; 95% CI=1.27-3.49) and alcohol use (OR=2.50; 95% CI=1.52-4.12) were associated with nonadherence. ^ Conclusions. Illicit drug use, alcohol use and nicotine dependence are formidable barriers to antiretroviral adherence in this population. Future research is needed to assess how to address these variables in the context of improving antiretroviral adherence for individuals living with HIV/AIDS.^

Club drug use and unprotected anal intercourse among HIV-seronegative men who have sex with men seeking HIV/STD testing at a local STD clinic in Houston

Objective. To explore (1) the association between "club drug" use and unprotected anal intercourse (UAI) and (2) the association between binge drug use and UAI among HIV seronegative men who have sex with men (MSM) seeking HIV/STD testing at a local clinic in Houston. ^ Study design. A sub-sample of 297 HIV seronegative MSM from a cross-sectional study of drug and sexual behavior in Houston was conducted in 2006. Patients who were seeking HIV/STD testing at a local MSM-identified STD clinic were recruited for an anonymous computer-assisted interview. Analysis of identified secondary data consisted of self-reported information about demographic characteristics, use of drugs, and sexual behaviors. ^ Results. With new and casual sex partners, there was a strong and statistically significant association between use of "club drugs" and UAI. No association between binge drug use and UAI was evident. Men aware of HIV seropositivity or unaware of the HIV serostatus of their primary partner were less likely to report UAI. ^ Conclusion. These data suggest that in the Houston area, HIV-negative MSM club drug users, particularly multiple drug users, are at higher risk of UAI than comparable MSMs who do not use club drugs. Episode-level data regarding binge use of these and other drugs, and UAI should be collected in future studies to explore their relationship. The 'new partner' category should be added to sex partner types to measure sex and drug use behaviors in future studies.^ Keywords. HIV-negative MSM; club drugs; unprotected anal intercourse; binge drug use. ^

The role of drug use in welfare to work: Evidence from Houston, Texas

The purpose of this study is to examine the prevalence of drug abuse among welfare recipients in Houston, TX and compare the work activities and employment barriers of drug abusers in order to better understand the potential effects of welfare reform for this population. Four hypotheses were tested comparing the work activities and employment barriers of drug abusers to others on welfare and the relative importance of drug abuse and employment barriers in predicting work activity. ^ This cross-sectional study examined the characteristics and work activities of 447 welfare recipients (81 drug abusers and 366 non-abusers) who were surveyed between October 1998 and April 1999 in Houston, TX. Subjects were introduced and recruited to participate in the study through a flyer, door to door visits, and peer driven recruitment/referral. ^ About 18% were found to be drug abusers, which is consistent with the national average (10–33%) among welfare recipients. Compared to others on welfare, drug abusers were less involved in work activities, and had more employment barriers. Employment barriers were found to be more predictive of welfare to work activities than drug abuse. The results suggest that alleviating employment barriers should be stressed in programs aimed at welfare recipients with drug abuse problems. ^

Childhood sexual victimization: Risk factor for drug use and sexual risk behaviors

The purpose of this dissertation was to survey men in the Harris County Jail (HCJ) to establish a more valid estimate of childhood sexual abuse (CSA) prevalence in a jailed-based population; to assess whether inmates with a history of CSA were at greater risk for use of drugs and alcohol and engaging in high-risk sexual behaviors than those without histories of childhood sexual abuse. ^ The first study determined the prevalence of childhood sexual abuse among incarcerated males in a county jail. In this study, sixty-three percent of the subjects reported having been sexually abused. Sixty-one percent reported abuse pre-puberty and 10% reported abuse post puberty. In pre-puberty abuse the initiation of first abuse occurred at a mean age of 5.6 years (SD 5.096, range: 2–13 years). ^ The second study explored the association between inmates with histories of CSA as a risk factor for sexual risk behaviors. A history of sexual abuse did not appear to be associated with an elevated risk of sexual risk behaviors. ^ The third study explored a history of drug use and a history of CSA among the inmates. A chi-square test showed that the inmates who reported a history of CSA, was significantly greater for the following drugs: Marijuana (02), Crack (03), Heroin/Morphine (.03), Amphetamines/Speed (01), Downers/Barbiturates (.001), Methamphetamine/Crystal Meth (.001), Valium .02), LSD/Acid (.001), and Inhalants (.001), p < .05). Significance was not found in alcohol, tobacco, cocaine, Quaaludes and methadone. ^ The research from this study provides empirical data supporting previous research. The current data shows that incarcerated inmates have a high prevalence of childhood sexual abuse and drug use. Sexual victimization as a child does not appear to be associated with an elevated risk of unsafe sexual behaviors. However, men who used drugs were twice as likely to have engaged in unprotected sex with casual and regular partners, and rarely used condoms with paid sex. Although our study methods do not permit a causal explanation for this association, we believe it is of concern. Finally, data in this study shows that sexually abused children are likely candidates for adult criminal behavior. ^

High-risk drug use and sexual behaviors among out-of-treatment drug users: An aging and life course perspective

High-risk injection drug use and the sexual behaviors that accompany it have large social and financial costs. Tailored treatments have been shown to successfully reduce high-risk behaviors. However, little is known about how age and age at first drug use are related to high-risk injection or sex behaviors. The current study draws on life course theory and hypothesizes that age will have a strong relationship with high-risk behaviors of out-of-treatment drug users. Data from the NIDA Cooperative Agreement was used to analyze the relationship between (1) age, and (2) age at first drug use with seven high-risk injection and sexual behavior variables. Negative binomial regression models revealed that high-risk sexual behavior decreases between 15.8 and 20.9% with each decade of age, while high-risk injection behavior increases between 32 and 67% with each decade of age after the addition of demographic controls. Both high-risk injection and high-risk sex behaviors are significantly reduced with a delayed age at first drug use. Previous research promotes interventions to reduce the high-risk sexual behaviors of older drug users. The current study suggests a refocusing of public health efforts on the high-risk injection habits of older drug users.^

A simulation study using the hybrid statistic and the meta-analysis t-test for data with matched and unmatched subjects in the interim analysis of clinical trials

An interim analysis is usually applied in later phase II or phase III trials to find convincing evidence of a significant treatment difference that may lead to trial termination at an earlier point than planned at the beginning. This can result in the saving of patient resources and shortening of drug development and approval time. In addition, ethics and economics are also the reasons to stop a trial earlier. In clinical trials of eyes, ears, knees, arms, kidneys, lungs, and other clustered treatments, data may include distribution-free random variables with matched and unmatched subjects in one study. It is important to properly include both subjects in the interim and the final analyses so that the maximum efficiency of statistical and clinical inferences can be obtained at different stages of the trials. So far, no publication has applied a statistical method for distribution-free data with matched and unmatched subjects in the interim analysis of clinical trials. In this simulation study, the hybrid statistic was used to estimate the empirical powers and the empirical type I errors among the simulated datasets with different sample sizes, different effect sizes, different correlation coefficients for matched pairs, and different data distributions, respectively, in the interim and final analysis with 4 different group sequential methods. Empirical powers and empirical type I errors were also compared to those estimated by using the meta-analysis t-test among the same simulated datasets. Results from this simulation study show that, compared to the meta-analysis t-test commonly used for data with normally distributed observations, the hybrid statistic has a greater power for data observed from normally, log-normally, and multinomially distributed random variables with matched and unmatched subjects and with outliers. Powers rose with the increase in sample size, effect size, and correlation coefficient for the matched pairs. In addition, lower type I errors were observed estimated by using the hybrid statistic, which indicates that this test is also conservative for data with outliers in the interim analysis of clinical trials.^

Is paromomycin an effective and safe treatment against cutaneous leishmaniasis? A meta-analysis of 14 randomized controlled trials.

BACKGROUND: High cost, poor compliance, and systemic toxicity have limited the use of pentavalent antimony compounds (SbV), the treatment of choice for cutaneous leishmaniasis (CL). Paromomycin (PR) has been developed as an alternative to SbV, but existing data are conflicting. METHODOLOGY/PRINCIPAL FINDINGS: We searched PubMed, Scopus, and Cochrane Central Register of Controlled Trials, without language restriction, through August 2007, to identify randomized controlled trials that compared the efficacy or safety between PR and placebo or SbV. Primary outcome was clinical cure, defined as complete healing, disappearance, or reepithelialization of all lesions. Data were extracted independently by two investigators, and pooled using a random-effects model. Fourteen trials including 1,221 patients were included. In placebo-controlled trials, topical PR appeared to have therapeutic activity against the old world and new world CL, with increased local reactions, when used with methylbenzethonium chloride (MBCL) compared to when used alone (risk ratio [RR] for clinical cure, 2.58 versus 1.01: RR for local reactions, 1.60 versus 1.07). In SbV-controlled trials, the efficacy of topical PR was not significantly different from that of intralesional SbV in the old world CL (RR, 0.70; 95% confidence interval, 0.26-1.89), whereas topical PR was inferior to parenteral SbV in treating the new world CL (0.67; 0.54-0.82). No significant difference in efficacy was found between parenteral PR and parenteral SbV in the new world CL (0.88; 0.56-1.38). Systemic side effects were fewer with topical or parenteral PR than parenteral SbV. CONCLUSIONS/SIGNIFICANCE: Topical PR with MBCL could be a therapeutic alternative to SbV in selected cases of the old world CL. Development of new formulations with better efficacy and tolerability remains to be an area of future research.

A Su Salud Injury Prevention expansion: Analysis of injury prevention perceptions in a Hispanic community

Unintentional injury is the leading cause of death for American ages one to 44 and is ranked in the top ten causes of death for all age groups (CDC, 2006a). A Su Salud Injury Prevention was developed to address injury prevention awareness and education. The program is a mass media education campaign that uses role models, mass media, and community outreach to prevent injury. In 2009, University Health System (UHS) expanded the program. Baseline data were collected from 426 residents in targeted neighborhoods northwest of downtown San Antonio to support the expansion. The purpose of this study was to explore injury perceptions, knowledge, and behaviors of adults living in the expansion area, and define the predominant factors associated with these perceptions. A secondary aim was to assess community awareness and willingness to participate in the program.^ Survey results showed motor vehicle crashes (MVC), falls, drinking and driving, and guns and assaults were considered the most serious injures for adults. The most serious child injuries were MVC, abuse and neglect, falls, and head injuries. Residents were knowledgeable of state seatbelt policy, and over 90% responded as compliant for seatbelt and child car seat use. Most were knowledgeable about drinking and driving state policy and negative outcomes. However, 70% of those reporting driving under the influence of alcohol within the last year engaged in repeat high risk behavior. Men and residents under the age of 55 were more likely to engage in repeat drinking and driving (OR= 3.6, 7.0 respectively). Residents consider injury prevention an important issue, and have interest in a local injury prevention program. Younger women are the most likely to participate in a local program as potential role models and volunteers.^ Results from the study are summarized into an injury prevention and demographic profile of the community that will be used to develop tailored injury prevention messages to create a more effective program, and support program coordinators in effective community engagement. Results will also be used as a comparative basis for future evaluation of a behavioral injury prevention program focused on a predominantly Mexican-American community.^

Optimal frequency of Imiquimod (Aldara(RTM)) 5% cream treatment of external genital warts in immunocompetent adults. Systematic review and meta-analysis

Genital warts are a sexually transmitted disease with high prevalence in the U.S. Imiquimod 5% cream is a self-applied treatment, prescribed three-times weekly, at bedtime, for 16 weeks. The post-marketing research addressed questions of imiquimod dosing frequency. MEDLINE, Embase, and the Cochrane Library were searched for randomized trials on efficacy and safety of imiquimod 5% cream with either three-times weekly or once-daily regimens to systemically review treatment options. Efficacy was evaluated by completely cleared warts at the end of treatment, and safety - by frequency of adverse events and at least one rest period taken from treatment. Six studies were selected for the analysis, including circumcised men, uncircumcised men, and women. The once-daily compared to three-times weekly regimen did not improve the efficacy, but resulted in increased incidence of local skin reactions and events, when at least one rest period was taken from treatment. The optimal regimen is three-times weekly.^

Bayesian generalized linear models for meta-analysis of diagnostic tests

With the recognition of the importance of evidence-based medicine, there is an emerging need for methods to systematically synthesize available data. Specifically, methods to provide accurate estimates of test characteristics for diagnostic tests are needed to help physicians make better clinical decisions. To provide more flexible approaches for meta-analysis of diagnostic tests, we developed three Bayesian generalized linear models. Two of these models, a bivariate normal and a binomial model, analyzed pairs of sensitivity and specificity values while incorporating the correlation between these two outcome variables. Noninformative independent uniform priors were used for the variance of sensitivity, specificity and correlation. We also applied an inverse Wishart prior to check the sensitivity of the results. The third model was a multinomial model where the test results were modeled as multinomial random variables. All three models can include specific imaging techniques as covariates in order to compare performance. Vague normal priors were assigned to the coefficients of the covariates. The computations were carried out using the 'Bayesian inference using Gibbs sampling' implementation of Markov chain Monte Carlo techniques. We investigated the properties of the three proposed models through extensive simulation studies. We also applied these models to a previously published meta-analysis dataset on cervical cancer as well as to an unpublished melanoma dataset. In general, our findings show that the point estimates of sensitivity and specificity were consistent among Bayesian and frequentist bivariate normal and binomial models. However, in the simulation studies, the estimates of the correlation coefficient from Bayesian bivariate models are not as good as those obtained from frequentist estimation regardless of which prior distribution was used for the covariance matrix. The Bayesian multinomial model consistently underestimated the sensitivity and specificity regardless of the sample size and correlation coefficient. In conclusion, the Bayesian bivariate binomial model provides the most flexible framework for future applications because of its following strengths: (1) it facilitates direct comparison between different tests; (2) it captures the variability in both sensitivity and specificity simultaneously as well as the intercorrelation between the two; and (3) it can be directly applied to sparse data without ad hoc correction. ^

A meta-analysis: Obesity and colorectal cancer screening

Of cancer death, colorectal cancer death ranks second in the United States. Obesity is an important risk factor for colorectal cancer (1). Early detection of colorectal cancer when it is localized can effectively reduce mortality of colorectal cancer and increase survival time of patients if they are treated. Also, previous studies showed that obese women were more likely to delay breast cancer screening and cervical cancer screening than normal weight women (2-5). However, results from prior studies demonstrating the relationship between obesity and colorectal cancer screening are not consistent. This research was done to conduct a meta-analysis of previous cross-sectional studies selected from the Medline database and to evaluate the association between obesity and colorectal cancer screening. While the odds ratio was not statistically different from one, the results from this meta-analysis under the random effects model showed that obese people are slightly less likely to have colorectal cancer screening compared to normal weight individuals (OR,0.93;95% CI 0.75-1.15). This meta-analysis was particularly sensitive to one individual study (6) and the effect of obesity on colorectal cancer screening was statistically significant (OR, 0.87; 95% CI, 0.81-0.92) after removing Heo's study. Further systematic studies focused on whether the effect of obesity on colorectal cancer screening is limited to women only are suggested. ^

A systematic review and meta-analysis of diabetes disease management programs

Context. Despite the rapid growth of disease management programs, there are still questions about their efficacy and effectiveness for improving patient outcomes and their ability to reduce costs associated with chronic disease. ^ Objective. To determine the effectiveness of disease management programs on improving the results of HbA1c tests, lipid profiles and systolic blood pressure (SBP) readings among diabetics. These three quantitative measures are widely accepted methods of determining the quality of a patient's diabetes management and the potential for future complications. ^ Data Sources. MEDLINE and CINAHL were searched from 1950 to June 2008 using MeSH terms designed to capture all relevant studies. Scopus pearling and hand searching were also done. Only English language articles were selected. ^ Study Selection. Titles and abstracts for the 2347 articles were screened against predetermined inclusion and exclusion criteria, yielding 217 articles for full screening. After full article screening, 29 studies were selected for inclusion in the review. ^ Data Extraction. From the selected studies, data extraction included sample size, mean change over baseline, and standard deviation for each control and experimental arm. ^ Results. The pooled results show a mean HbA1c reduction of 0.64%, 95% CI (-0.83 to -0.44), mean SBP reduction of 7.39 mmHg (95% CI to -11.58 to -3.2), mean total cholesterol reduction of 5.74 mg/dL (95% CI, -10.01 to -1.43), and mean LDL cholesterol reduction of 3.74 mg/dL (95% CI, -8.34 to 0.87). Results for HbA1c, SBP and total cholesterol were statistically significant, while the results for LDL cholesterol were not. ^ Conclusions. The findings suggest that disease management programs utilizing five hallmarks of care can be effective at improving intermediate outcomes among diabetics. However, given the significant heterogeneity present, there may be fundamental differences with respect to study-specific interventions and populations that render them inappropriate for meta-analysis. ^

Ascertainment, meta-analysis and reporting of adverse reactions in clinical trials of antibiotics

The ascertainment and analysis of adverse reactions to investigational agents presents a significant challenge because of the infrequency of these events, their subjective nature and the low priority of safety evaluations in many clinical trials. A one year review of antibiotic trials published in medical journals demonstrates the lack of standards in identifying and reporting these potentially fatal conditions. This review also illustrates the low probability of observing and detecting rare events in typical clinical trials which include fewer than 300 subjects. Uniform standards for ascertainment and reporting are suggested which include operational definitions of study subjects. Meta-analysis of selected antibiotic trials using multivariate regression analysis indicates that meaningful conclusions may be drawn from data from multiple studies which are pooled in a scientifically rigorous manner. ^

Bayesian inference and its application to meta-analysis of epidemiologic data

In Part One, the foundations of Bayesian inference are reviewed, and the technicalities of the Bayesian method are illustrated. Part Two applies the Bayesian meta-analysis program, the Confidence Profile Method (CPM), to clinical trial data and evaluates the merits of using Bayesian meta-analysis for overviews of clinical trials.^ The Bayesian method of meta-analysis produced similar results to the classical results because of the large sample size, along with the input of a non-preferential prior probability distribution. These results were anticipated through explanations in Part One of the mechanics of the Bayesian approach. ^