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Biomedical subjects

Robert G Carlson

Publications and source records attributed to Robert G Carlson.

At least 19 recordsLinked to original sources
PubMed2006

Respondent-driven sampling in the recruitment of illicit stimulant drug users in a rural setting: findings and technical issues.

Increasingly, respondent-driven sampling (RDS) is being applied to study not-in-treatment users of illicit drugs. Although RDS has been successfully applied in recruiting active users in densely-populated, metropolitan areas, its utility with hidden populations in rural areas has yet to be determined. This study critically evaluates the sample of not-in-treatment, illicit stimulant drug users (n=249) recruited from the application of RDS in three rural counties in west-central Ohio. The findings of this study largely support the results of earlier studies in urban areas and suggest that RDS is a useful method of sampling hidden drug using populations in less densely populated rural areas. Some limitations of RDS are also discussed.

Adult↗
PubMed2006

Prevalence and correlates of current depressive symptomatology among a community sample of MDMA users in Ohio.

Research suggests that MDMA can cause serotonin depletion as well as serotonergic neurodegradation that may result in depression among users of the drug. Several small-scale studies have used various editions of the Beck Depression Inventory (BDI) to quantify depressive symptomatology among MDMA users. This study represents the largest application of the BDI to date to explore symptoms of current depression among a community sample of young adult MDMA users (n = 402). Internal consistency testing of the BDI-II with this sample revealed Cronbach's alpha = .92. Results show a mean BDI-II score of 9.8, suggesting low levels of depressive symptomatology among study participants. Two-thirds of the sample had scores that placed them in the non-depressed/minimal depression category, while 4.7% had scores indicative of severe depression. Logistic regression analysis revealed that men were significantly less likely than women and people who used opioids were significantly more likely than non-users to have higher levels of depressive symptomatology. Higher lifetime occasions of MDMA use were marginally related to symptoms of serious depression.

Adult↗
PubMed2006

Emergency department utilization by crack-cocaine smokers in Dayton, Ohio.

The objective of this study was to determine the frequency, principal diagnoses, and correlates of emergency department (ED) visits made by persons with a history of crack-cocaine use (n = 333) over a 3-year period. Data were collected from participant self-reports and hospital records. During the study a total of 643 ED visits were made by 211 people, ranging from 53.5 to 76.7/100 persons/year. Injury and poisoning accounted for the largest single category of ED visits (29.5%). Men had lower odds of visiting the ED (OR=0.79, 95%CI=0.62-0.99), as did participants with higher levels of education (OR=0.83, 95%CI=0.73-0.94). Number of times in drug abuse treatment (OR=1.04, 95%CI=1.01-1.09), having a chronic disease (OR=1.46, 95%CI=1.06-1.99), and higher Addiction Severity Index composite medical scores (OR=1.62, 95%CI=1.15-2.29) increased the odds of an ED visit. Factors in addition to drug use are likely to affect ED utilization rates among crack-cocaine smokers.

Adolescent↗
PubMed2006

Psychiatric disorders and their correlates among young adult MDMA users in Ohio.

This study describes the lifetime prevalence, correlates, and age of onset of selected psychiatric disorders among a community sample of MDMA users (n = 402), aged 18 to 30, in Ohio. Participants responded to interviewer-administered questionnaires, including sections of the computerized Diagnostic Interview Schedule for DSM-IV. Fifty-five percent of the sample had at least one lifetime disorder, with major depression (35.3%) and antisocial personality disorder (ASPD) (25.4%) the most common. Proportionately more women were diagnosed with depression, generalized anxiety disorder, and posttraumatic stress disorder (PTSD), while proportionately more men were diagnosed with ASPD. Proportionately more non-White participants had attention deficit/hyperactivity disorder (AD/HD). Higher levels of education were associated with proportionately less PTSD, ASPD, and AD/HD. Higher frequencies of MDMA use were associated with proportionately more ASPD and AD/HD. Comparing the age of first MDMA use with the age of onset for selected psychiatric disorders revealed that for most participants disorders preceded use. Multivariate analysis revealed participants with more than a high school education were less likely to have experienced a lifetime disorder, while those who had used MDMA more than 50 times were more likely. Variations in the prevalence of psychiatric disorders have practical implications for drug abuse prevention and treatment programs.

Adolescent↗
PubMed2006

Needles in the haystacks: the social context of initiation to heroin injection in rural Ohio.

Although there has been much research on the social context of heroin injection, little has been reported outside of major urban areas. This article examines contextual factors associated with initiation to heroin injection in rural Ohio, based on semistructured qualitative interviews and focus groups involving 25 recent heroin injectors (12 women, 13 men) recruited from three contiguous counties between June 2002 and February 2004. Curiosity about the drug's effects, the growing pressures of drug dependence and economic need, and the influence of intimate and group relations were all identified as factors that offset fears commonly associated with injection. This study complements other research on the social ecology of heroin injection and may contribute to improved services for injection drug users in rural areas and small communities.

Adolescent↗
PubMed2006

Perspectives on health among adult users of illicit stimulant drugs in rural Ohio.

CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.

Adult↗
PubMed2006

The role of African-American clergy in providing informal services to drug users in the rural South: preliminary ethnographic findings.

To date, no ethnographic studies of the role of African-American clergy in providing informal services to drug users in the rural South have been reported. We use qualitative interviews with 15 African-American ministers and 26 African-American drug users in Arkansas' Mississippi River Delta region to explore this issue. All drug users reported significant religiosity, and 9 had discussed drug problems with clergy. Every minister had provided assistance to at least one drug user or their family during the previous year, including: direct counseling; referrals to treatment programs; aiding negotiations with formal institutions; and providing for basic needs. Ministers stated that clergy are not well-prepared to address drug problems, and most acknowledged a need for professional training. They also discussed barriers to education. The findings contribute to understanding rural informal drug treatment resources. They suggest that professional treatment providers should investigate the potential benefits of improving outreach efforts to assist African-American ministers engaged in drug abuse issues.

Adult↗
PubMed2005

Drug use practices among MDMA/ecstasy users in Ohio: a latent class analysis.

This study describes the drug use practices among 402 recent MDMA (3,4-methelyenedioxymethamphetamine) users recruited in Ohio using respondent-driven sampling. About 64% of the participants were men, 81.6% were white, and the mean age was 20.9 years. Latent class analysis was used to identify subgroups of MDMA users. Use of cocaine, opioids, amphetamines, tranquilizers, inhalants, marijuana, and hallucinogens during the previous 6 months, and days of "drunkenness" in the past 30, were used for classification. A three-class model was preferable and reflected "Limited range," "Moderate range," and "Wide range" drug use patterns. For example, the conditional probability of using opioids during the previous 6 months was .07 in Class 1, .59 in Class 2, and .88 in Class 3. Other substances followed similar patterns. Predictors of class membership were examined in a multinomial logit model in which the "Limited range" Class was treated as the reference group. Participants who were white, younger, and who reported more than 10 occasions of MDMA use were more likely to be in the "Wide range" drug use Class. Latent class analysis is a useful method to help describe and understand variability in polydrug use patterns.

Adolescent↗
PubMed2005

Nonmedical drug use among stimulant-using adults in small towns in rural Ohio.

This study describes the drug-use practices and treatment histories of 249 not-in-treatment, drug-using individuals living in small towns in rural Ohio. Respondent-driven sampling was used to recruit participants who answered questionnaires administered by interviewers. Descriptive statistics and latent class analysis (LCA) were used to examine the data. The illicit drugs most commonly used in the 6 months before entering the study were marijuana (89.6%), cocaine hydrochloride (80.3%), and crack cocaine (76.3%). Injection drug use was not uncommon. About a third of the sample experienced drunkenness frequently. Less than 14% had been in substance abuse treatment recently. LCA revealed two groups: (1) heavy users of virtually all drug classes and (2) moderate-to-light users of fewer drug classes. White and younger people were more likely to be classified in the heavy user group. The results suggest that comprehensive substance abuse prevention and treatment programs are needed in rural communities.

Adult↗
PubMed2005

From "Candy Kids" to "Chemi-Kids": a typology of young adults who attend raves in the midwestern United States.

Although young people attending raves have been most visibly associated with the use of ecstasy and other "club drugs" in the United States, there is reason to believe that they are not a homogenous group in terms of their drug use practices. The purpose of this article is to begin developing a typology of young adult ecstasy users involved in the rave subculture--known as Ravers or Party Kids. The study is based on focus groups and qualitative interviews conducted between November 2001 and September 2003 with 36 current and former ecstasy users, aged 19-31, in central Ohio, as well as participant observation conducted in raves, clubs, and bars where "club drugs" are often used. Findings suggest the existence of five main subgroups in attendance at raves--Chemi-Kids, Candy Kids, non-affiliated Party Kids, Junglists, and Old School Ravers. These groups differ in regard to musical taste, philosophy, style of clothing worn, amount of time in the rave subculture, and most importantly, patterns of drug use. For example, while the use of ecstasy appears most common among Candy Kids, Junglists tend to be more involved with the use of ketamine and methamphetamine. The use of alcohol, cocaine, marijuana, and hallucinogens is also widespread in the rave subculture. The typology can aid in the development of communication strategies necessary for successful prevention activities among some categories of ecstasy users.

Adult↗
PubMed2005

Barriers and pathways to diffusion of methamphetamine use among African Americans in the rural South: preliminary ethnographic findings.

There are no studies of African Americans methamphetamine use in the South where it is widespread among whites. We describe factors that inhibit or facilitate the diffusion of methamphetamine use among African Americans based on qualitative interviews with 86 drug users in rural Arkansas and Kentucky. Results suggest low prevalence of methamphetamine use among African Americans, and interviewees cited several barriers to its diffusion which were linked to the drug's ingredients, psychoactive and physiological effects, difficulty in accessing distribution networks, and established African-American preference for cocaine. Fourteen African Americans reported methamphetamine use and discussed pathways to it. Possible increases in African- American methamphetamine use merits further investigation.

Adult↗
PubMed2004

Respondent-driven sampling to recruit MDMA users: a methodological assessment.

Recruiting samples that are more representative of illicit drug users is an on-going challenge in substance abuse research. Respondent-driven sampling (RDS), a new form of chain-referral sampling, is designed to eliminate the bias caused by the non-random selection of the initial recruits and reduce other sources of bias (e.g. bias due to volunteerism and masking) that are usually associated with regular chain-referral sampling. This study provides a methodological assessment of the application of RDS among young adult MDMA/ecstasy users in Ohio. The results show that the sample compositions converged to equilibrium within a limited number of recruitment waves, independent of the characteristics of the initial recruits (i.e. seeds). The sample compositions approximated the theoretical equilibrium compositions, and were not significantly different from the estimated population compositions-with the exception that White respondents were over-sampled and Black respondents were under-sampled. The effect of volunteerism and masking on the sampling process was found not to be significant. Though identifying productive seeds and improving the referral rate are significant challenges when implementing RDS, the findings demonstrate that RDS is a flexible and robust sampling method. RDS has the potential to be widely employed in studies of illicit drug-using populations.

Epidemiologic Research Design↗
PubMed2004

Sources of information about MDMA (3,4-methylenedioxymethamphetamine): perceived accuracy, importance, and implications for prevention among young adult users.

The goal of this cross-sectional study was to assess the perceived accuracy and the importance of various sources of information about MDMA/ecstasy among young adult users. A respondent driven sampling plan was used to recruit a community sample of recent ecstasy users (n = 304), aged 18-30, in Ohio, who responded to structured interviews. Friends, drug abuse treatment programs, and physicians were perceived to be the most accurate sources of information about ecstasy by 45.7, 37.2, and 30.3% of the sample, respectively. Friends were considered the most important source of information about ecstasy (40.2%), followed by web sites like DanceSafe (16.2%), and MTV/VH1 television specials (6.9%). About half the sample used the Internet to obtain information about ecstasy, with younger and more educated participants significantly more likely to do so. Educated users were also significantly more likely to consider the Internet to be an important source of information. Web sites like DanceSafe were visited by four times as many users as government-sponsored web sites. Findings support the development of peer-oriented, network strategies to reach ecstasy users with prevention messages. Efforts to make prevention web sites more attractive should be considered.

Adolescent↗
PubMed2004

MDMA/Ecstasy use among young people in Ohio: perceived risk and barriers to intervention.

In the past several years, the use of MDMA (Ecstasy) has increased substantially in the United States and in many countries around the world. Although this increase has been associated with the dance club and rave scenes, Ecstasy use has expanded into new settings. At the same time, the diversity of people using the drug has also grown. Given the increasing, although unclear, evidence that MDMA has the potential to cause neurotoxicity and various psychological problems under certain conditions among humans, understanding how active users perceive the risks associated with Ecstasy use can help to inform prevention and intervention approaches. Based on audiotaped focus groups and individual interviews conducted with 30 Ecstasy users in Dayton and Columbus, Ohio, this article explores these and other issues. Results demonstrate that beyond the risk of obtaining something potentially deadly instead of MDMA, most users do not associate risks of neurotoxicity or psychological problems with Ecstasy use. Active users look to harm-reduction approaches for answers to using Ecstasy safely; prevention messages like, "just say no to drugs" are largely ignored. Because Ecstasy is commonly used among small groups of friends, peer leader or other social network intervention approaches may be promising.

Adolescent↗
PubMed2004

The prevalence of psychiatric disorder among a community sample of crack cocaine users: an exploratory study with practical implications.

The Diagnostic Interview Schedule for DSM-IV was used to assess the lifetime prevalence of psychiatric disorder among not-in-treatment crack cocaine users (N = 313). The most common dependencies involved cocaine (59.7%), alcohol (37.7%), and cannabis (12.1%). The most common nondependency disorders were antisocial personality disorder (ASPD; 24%), depression (17.8%), and posttraumatic stress disorder (PTSD; 11.8%). Comorbidity was present in 36.4% of the sample. Proportionately more white than black users were dependent on cocaine, alcohol, amphetamine, and sedative-hypnotics. More white than black users experienced ASPD, depression, PTSD, and attention deficit disorder. Proportionately fewer black users suffered comorbid disorders. Proportionately more men had ASPD, whereas more women had PTSD and phobias. Multinominal modeling revealed that black users and users with a high school education were less likely to have comorbid disorders; married users were less likely to have nondependency disorders. White crack users were more likely to have comorbidity, complicating their treatment.

Adult↗
PubMed2003

Amino acid and peptide analysis using derivatization with p-nitrophenol-2,5-dihydroxyphenylacetate bis-tetrahydropyranyl ether and capillary electrophoresis with electrochemical detection.

The amine derivatization reagent p-nitrophenol-2,5-dihydroxyphenylacetate bis-tetrahydropyranyl ether (NDTE) was used in conjunction with capillary electrophoresis (CE) and electrochemical detection (EC) for the pre-separation derivatization of primary amine analytes present in aqueous solution. Glycine, several dipeptides and angiotensin II were used as model analytes. A miniaturized EC detection cell was designed and fabricated, which featured a fractured-joint field decoupler with a fixed end-column carbon fiber electrode. When a series of glycine and angiotensin II calibration solutions were derivatized with NDTE followed by CE-EC determination, linear calibration plots resulted with pre-derivatization concentration limits of detection of 500 nM (106 attomoles on-column) and 6 microM (1.275 femtomoles on-column), respectively.

Amino Acids↗
PubMed2002

Predictors of drug abuse treatment entry among crack-cocaine smokers.

The goal of this study was to identify factors that predicted drug abuse treatment program entry among a community sample of 430 crack-cocaine users. Subjects were recruited using a targeted sampling methodology and responded to interviewer-administered questionnaires at 6 months intervals over a 3-year period. At baseline, 40.5% (n=174) reported they had never been in a drug abuse treatment program. During the observation period, 37.7% (n=162) of the sample reported they had entered a program. Of these, 43.8% (n=71) reported that their treatment was court-ordered. Slightly more than one-quarter (n=44) entered treatment for the first time. A host of variables, including individual characteristics, frequency and duration of crack use, frequency of drunkenness, Addiction Severity Index (ASI) family/social, medical, and psychiatric status composite scores, perceived need for treatment, history of treatment, and medical insurance coverage, was explored. The results of Cox proportional hazards model suggested that younger people, users with more severe legal problems, people who perceived a need for treatment, and individuals with prior treatment experience had a greater likelihood of entering treatment. Developing a strategy to practically apply these findings may facilitate treatment entry among a population involved with a dangerous and debilitating drug.

Adult↗