Cross-sectional and longitudinal neural predictors of physical activity and sedentary behaviour from a 6-month randomized controlled trial

A sedentary lifestyle offers immediate gratification, but at the expense of long-term health. It is thus critical to understand how the brain evaluates immediate rewards and long-term health effects in the context of deciding whether to engage in moderate-to-vigorous physical activity (MVPA) or sedentary behaviour (SB). In this secondary analysis of a 6-month randomized controlled trial to increase MVPA and reduce SB among community-dwelling adults, we explored how neural activity during an executive control task was associated with MVPA and SB levels. At baseline, a subset of participants (n = 26/61) underwent task-based functional magnetic resonance imaging (fMRI) to examine neural activity underlying executive control using the Now/Later task. MVPA and SB were measured objectively using the Sensewear Mini at baseline, and 2, 4, and 6 months follow-up. We then examined the associations of baseline neural activation underlying executive control with: (1) baseline MVPA or SB; and (2) changes in MVPA and SB over 6 months. Our results determined that there is a complex neurocognitive system associated with MVPA levels, while SB appears to lack any neurocognitive control. In other words, MVPA appears to require neurocognitive effort, while SB may be the default behavioural pattern in adults.

The independent associations of physical activity and sleep with neural activity during an inhibitory task: cross-sectional results from the MONITOR-OA study

Sleep and physical activity (PA) are important for the maintenance of executive functions. Whether these lifestyle factors independently contribute to associated neural correlates of executive functions is unknown. We therefore investigated the independent associations of PA and sleep with neural activity during executive performance using task-based functional magnetic resonance imaging (fMRI). Baseline data from a subset of participants (n = 29) enrolled in a randomised trial were used for this cross-sectional analysis. We measured PA, sleep duration and efficiency for 7 days using the SenseWear Mini and examined neural activity underlying response inhibition using the Go/NoGo executive performance task. Brain activation patterns during the NoGo condition were contrasted to activation patterns during the Go condition (i.e., NoGo-Go). We constructed two separate models (controlling for age, sex, and education) to examine the independent associations of (i) PA and sleep duration; and (ii) PA and sleep efficiency with brain activation. Significant clusters were corrected for multiple comparisons (p < 0.05) to determine region-specific activation patterns. The mean (SD) participant age was 61 (9) years, and 79% were female. PA was independently associated with greater task-related blood-oxygen-level dependent (BOLD) signal activity in the left cingulate gyrus; longer sleep duration was independently associated with greater BOLD signal activity in the left putamen. Higher sleep efficiency was independently associated with increased BOLD signal activity in the left hippocampus. PA, sleep duration, and efficiency are each independently associated with greater neural activity underlying response inhibition, which further illustrates that PA and sleep are each uniquely important for brain health.

Cardiometabolic risk, biological sex, and age do not share an interactive relationship with cognitive function: A cross-sectional analysis of the Canadian Longitudinal Study on Aging

It is unclear whether cardiometabolic risk shares an interactive relationship with age-associated differences in cognition, and whether this relationship varies by biological sex. We conducted a cross-sectional analyses using baseline data from the Canadian Longitudinal Study on Aging (2010-2015) to examine whether: 1) cardiometabolic risk has an interactive relationship with age-associated cognition; and 2) interactive effects are sex-dependent. We measured memory, executive function, and verbal fluency in the Comprehensive cohort (n=25,830; 45-86 years). Each cognitive domain was modeled using restricted cubic splines for age and each cardiometabolic risk factor (HbA1c, HSCRP, TG, and LDL and HDL cholesterol). Sex was included as a predictor in all models. Wald chi-square statistics were used to determine the relative importance of age, cardiometabolic risk, sex, and their interactive effects on cognition. Age was the most important variable in each model (proportion χ2=34-48%). Biological sex was the second most important variable for memory (proportion χ2=26%), but was unimportant for executive function and verbal fluency (proportion χ2=3-5%). Cardiometabolic risk factors were unimportant predictors in each model (proportion χ2=1-3%). Two and three-way interactions between cardiometabolic risk, age, and sex were also unimportant (proportion χ2=0-2%). Thus, cardiometabolic risk factors did not meaningfully account for age-associated differences in cognition, and these associations (or lack thereof) did not vary by sex. Novelty: Males have poorer age-associated cognitive performance than females Females and males differ in cardiometabolic risk across middle and older adulthood Cardiometabolic risk has a small association with age-associated cognition, and there are no sex differences in this relationship.

An automatic estimation of the rest-interval for MotionWatch8© using uniaxial movement and lux data

Background

Poor sleep is linked with chronic conditions common in older adults, including diabetes, heart disease, and dementia. Valid and reliable field methods to objectively measure sleep are thus greatly needed to examine how poor sleep impacts older adults. Wrist-worn actigraphy (WWA) is a common objective measure of sleep that uses motion and illuminance data to estimate sleep. The rest-interval marks the time interval between when an individual attempts to sleep and the time they get out of bed to start their day. Traditionally, the rest-interval is scored manually by trained technicians, however algorithms currently exist which automatically score WWA data, saving time and providing consistency from user-to-user. However, these algorithms ignore illuminance data and only considered motion in their estimation of the rest-interval. This study therefore examines a novel algorithm that uses illuminance data to supplement the approximation of the rest-interval from motion data.

Methods

We examined a total of 1086 days of data of 129 participants who wore the MotionWatch8© WWA for ≥14 nights of observation. Resultant sleep measures from three different parameter settings were compared to sleep measures derived following a standard scoring protocol and self-report times.

Results

The algorithm showed the strongest correlation to the standard protocol (r = 0.92 for sleep duration). There were no significant differences in sleep duration, sleep efficiency and fragmentation index estimates compared to the standard scoring protocol.

Conclusion

These results suggest that an automated rest-interval scoring method using both light exposure and acceleration data provides comparable accuracy to the standard scoring method.

Risk factors for recurrent falls in older adults: A systematic review with meta-analysis

Older adults who fall recurrently (i.e., 2 or more falls/year) are at risk of functional decline and mortality. Understanding which risk factors for recurrent falls are most important will inform secondary fall prevention strategies that can reduce recurrent falls risk. Thus, we conducted a systematic review with meta-analysis to determine the relative risk of recurrent falls for different types of falls risk factors. MEDLINE, EMBASE, PsycINFO, and CINAHL databases were searched on April 25, 2019 (Prospero Registration: CRD42019118888). We included peer-reviewed prospective studies which examined risk factors that contributed to recurrent falls in adults aged ≥ 60 years. Using the falls risk classification system of Lord and colleagues, we classified each risk factor into one of the following domains: 1) balance and mobility; 2) environmental; 3) psychological; 4) medical; 5) medication; 6) sensory and neuromuscular; or 7) sociodemographic. We calculated the summary relative risk (RR) for each domain and evaluated the risk of bias and quality of reporting. Twenty-two studies were included in this systematic review and meta-analysis. Four domains predicted recurrent falls: balance and mobility (RR:1.32;95 % CI:[1.10, 1.59]), medication (RR:1.53;95 % CI:[1.11, 2.10]), psychological (RR:1.35;95 % CI:[1.03, 1.78]), and sensory and neuromuscular (RR:1.51;95 % CI:[1.18, 1.92]). Each of these four domains can be viewed as a marker of frailty. The risk of bias was low, and the study quality was high (minimum:19/22). Older adults with markers of frailty are up to 53 % more likely to experience recurrent falls. Strategies that identify and resolve frailty markers should be a frontline approach to preventing recurrent falls.

Effects of Resistance Exercise with Instability on Cognitive Function (REI Study): A Proof-Of-Concept Randomized Controlled Trial in Older Adults with Cognitive Complaints

Background: Activities which simultaneously challenge both physical and cognitive function are promising strategies for promoting cognitive function. Objective: To examine the effects of resistance exercise with instability and traditional resistance exercise compared with a health education control on cognitive function in older adults with cognitive complaints. Methods: Sixty-seven participants were randomized to either 12 weeks of thrice-weekly resistance exercise (RE = 23), RE with instability (REI = 22), or a weekly health education control (CON = 22). At each training session, RE and REI participants performed seven exercises for three sets and 10–15 repetitions. REI participants performed each exercise using instability devices. The primary outcome was a composite score of global cognitive function. Secondary outcomes included composite scores for cognitive sub-domains and physical function. Results: Most participants were women (REI: 77%; RE = 78%; CON = 77%; mean age of 71 years), and did not need transport to the intervention site. At completion, compared with CON, REI and RE did not significantly improve on global cognition or each cognitive sub-domain. Both exercise groups improved on the timed up and go (REI - CON: –1.6 s, 95% CI: [–2.6, –0.5]; RE - CON: –1.4 s, 95% CI: [–2.4, –0.5) and 1-RM (REI - CON: 24 kg, 95% CI: [11, 36]; RE - CON: 25 kg, 95% CI: [12, 37]). An exploratory contrast showed that compared with RE, REI promote greater gains on global cognition (2.20, 95% CI: [0.10, 4.31]) and memory (1.34; 95% CI: [0.15, 2.54]). Conclusion: REI did not substantially improve cognitive function but did promote physical function among older adults with cognitive complaints. However, compared with RE, REI improved global cognition and memory.

Perceived risk associated with ecstasy use: a latent class analysis approach

This study aims to define categories of perceived health problems among ecstasy users based on observed clustering of their perceptions of ecstasy-related health problems. Data from a community sample of ecstasy users (n=402) aged 18 to 30, in Ohio, was used in this study. Data was analyzed via Latent Class Analysis (LCA) and Regression. This study identified five different subgroups of ecstasy users based on their perceptions of health problems they associated with their ecstasy use. Almost one third of the sample (28.9%) belonged to a class with "low level of perceived problems" (Class 4). About one fourth (25.6%) of the sample (Class 2), had high probabilities of "perceiving problems on sexual-related items", but generally low or moderate probabilities of perceiving problems in other areas. Roughly one-fifth of the sample (21.1%, Class 1) had moderate probabilities of perceiving ecstasy health-related problems in all areas. A small proportion of respondents (11.9%, Class 5) had high probabilities of reporting "perceived memory and cognitive problems", and of perceiving "ecstasy-related problems in all areas" (12.4%, Class 3). A large proportion of ecstasy users perceive either low or moderate risk associated with their ecstasy use. It is important to further investigate whether lower levels of risk perception are associated with persistence of ecstasy use.

The epidemiology of physical attack and rape among crack-using women

This prospective study examines the epidemiology of physical attack and rape among a sample of 171 not-in-treatment, crack-cocaine using women. Since initiating crack use, 62% of the women reported suffering a physical attack. The annual rate of victimization by physical attack was 45%. Overall, more than half of the victims sought medical care subsequent to an attack. The prevalence of rape since crack use was initiated was 32%, and the annual rate was 11%. Among those women having been raped since they initiated crack use, 83% reported they were high on crack when the crime occurred as were an estimated 57% of the perpetrators. Logistic regression analyses showed that duration of crack use, arrest for prostitution, and some college education were predictors of having experienced a physical attack. Duration of crack use and a history of prostitution were predictors of suffering a rape. Drug abuse treatment programs must be sensitive to high levels of violence victimization experienced by crack-cocaine using women. Screening women for victimization, and treating the problems that emanate from it, may help make drug abuse treatment more effective.

Constructing a consensus-based prevention outcome measurement instrument

This article describes Ohio's Prevention Evaluation Project (PEP). The purpose of the project was to develop a process and instrument to assess behavioral and attitudinal outcomes in primary drug abuse prevention programs targeting young people aged twelve to seventeen. One of PEP's principal achievements was the inclusion of community prevention program providers from throughout the state in the evaluation instrument development. The effort produced a self-administered questionnaire to capture data on young peoples' drug use practices, attitudes toward drugs, and problematic behaviors. Most significantly, the product produced was the acceptance and endorsement of community-based programs. The forty-one-item questionnaire has good to excellent reliability for virtually all measures, as assessed by the test-retest method. The instrument is a product of a process that brought together a university-based research team, state alcohol and drug abuse prevention administrators, and representatives of public programs. PEP demonstrates how to productively link service providers, administrators, and evaluators to develop a process for assessing the effectiveness of prevention programs. The process and tools described serve as a model for other communities wanting to evaluate their prevention programming.

Longitudinal application of the medical outcomes study 36-item short-form health survey with not-in-treatment crack-cocaine users

BACKGROUND

The Medical Outcomes Study SF-36 has been used infrequently with substance abusers.

OBJECTIVES

The objectives of this study were to use the SF-36 to assess changes in the health status of crack-cocaine users over time, to determine the characteristics of users who change, to assess the influence of frequency of crack use on SF-36 health status, and to determine the utility of the SF-36 with crack users.

DESIGN

A multilevel model was used to analyze data that were collected every 6 months over a 2-year period.

SUBJECTS

The sample consisted of 439 not-in-treatment crack-cocaine users.

MEASURES

The SF-36 was administered at baseline and follow-up interviews. Data on the frequency of crack-cocaine use were also collected.

RESULTS

On average, SF-36 health status remained fairly static during the study although statistically significant increases in scores occurred on the social functioning and role-emotional subscales. Variation in subjects' health trajectories occurred but was not, for the most part, explained by individual characteristics. Frequency of crack use was negatively related to scores on the physical functioning, social functioning, and mental health subscales. Most subscales did not reflect what are commonly recognized to be the health-compromising effects of cocaine use, raising questions about the use of the SF-36 with illicit drug users.

CONCLUSIONS

Changes in crack users' SF-36 health status were uncommon. Frequency of crack use was negatively associated with health status. Several SF-36 subscales may be helpful in studies involving illicit drug users in which limited assessments of health status are needed.

Crack-cocaine use and health status as defined by the SF-36

The Medical Outcomes Study Short Form 36 (SF-36) was administered to 443 not-in-treatment, crack-cocaine smokers to explore the relationship between frequency of crack, alcohol, and tobacco use, addiction to these drugs, and health status. The reliability of the SF-36 with crack smokers was also assessed. Statistically significant, negative associations emerged between frequency of crack use and all SF-36 subscales except physical functioning. There were not significant associations between frequency of alcohol or tobacco use and any SF-36 subscale. Self-assessed addiction to crack was strongly and negatively associated with all SF-36 subscales: alcohol and tobacco addiction were also negatively associated with health status, but not to the degree of crack. The SF-36 produces reliable data on the health status of crack users and, as such, may have a useful role in assessments involving crack-using populations.

Crack-cocaine users as victims of physical attack

This study evaluates the correlates of physical attack among people who use crack cocaine in Dayton, Ohio. Using a retrospective and prospective natural history design, data from baseline and 1-year follow-up interviews were used to calculate the prevalence of physical attack and the annual rate of physical attack suffered by 440 not-in-treatment crack-cocaine users. Logistic regression was used to determine the correlates of physical attack. The lifetime prevalence of physical attack was 63.0%; the annual rate was 36.8%. At baseline, daily crack users were more likely to report a previous attack since they began using crack (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.18-2.77). Longer duration of crack use was also associated with experiencing an attack (OR, 1.09; 95% CI, 1.04-1.14). Between baseline and 12-month follow-up, the odds of men being attacked were significantly less than those for women (OR, 0.48; 95% CI, 0.23-0.99). Physical attack is widespread among crack-cocaine users, and does not vary by ethnicity. Injuries often result in the need for medical care. Over the short term, women are at increased risk. Accessible and effective drug abuse treatment is needed to diminish the harm this population suffers.

Evaluation of HIV risk reduction intervention programs via latent growth model

The latent growth model (LGM) has drawn increasing attention in behavioral studies using longitudinal data. The LGM captures the level and trajectory of behavior change, variation in both the initial status and the trend of behavior change, as well as the time-ordered covariation between the initial status and change. This study demonstrates how the LGM can be applied in the evaluation of intervention programs targeting HIV risk behavior among drug users. Multi-group piecewise latent growth models were fit to longitudinal data with three repeated response measures.

Understanding HIV risks of chronic drug-using men who have sex with men

Focus groups and individual structured interviews were conducted in six cities with 98 predominantly street-recruited men who had a recent history of smoking crack or injecting drugs and who reported having had sex with other men (MSM) in the past year. Twenty-six focus groups explored the cultural and social context of participant's drug use and sexual activity and addressed outreach and HIV prevention issues pertinent to this population. Narrative summaries developed from verbatim focus group transcripts identified seven themes: (a) sexual orientation and gender identity; (b) interactions within and between MSM networks; (c) drug use, sexual activity and personal relationships; (d) HIV transmission bridges; (e) preferred HIV information sources; (f) HIV knowledge, prevention practices and risk behaviours; and (g) availability of HIV and drug-related services. Of the 98 MSM drug users, 42% identified publicly as gay or homosexual; 35% identified publicly, but only 21% privately, as heterosexual. A total of 51% had one or more female sex partners in the past year. There was a high frequency of unprotected sex in conjunction with drug use and a distinct preference for having sex when high. For most participants, drug use rather than sexual orientation formed the core of personal identity. Participants reported associating primarily with other drug users, usually MSM, and had limited contact with people who did not use drugs and the mainstream gay community. Participants' sexual and drug-injecting activities were judged to be a bridge for transmission of HIV to both people who used drugs and those who did not.

HIV needle risk behaviors and drug use: a comparison of crack-smoking and nonsmoking injection drug users in Ohio

This study compares the drug use and needle risk behaviors among 733 crack-smoking injection drug users (IDUs) and 518 nonsmoking IDUs. Participants were recruited in Dayton and Columbus, Ohio, for the Cooperative Agreement for AIDS Community-Based Outreach/Intervention Research Program from 1992 to 1996. Crack-smoking IDUs were more likely to be male, African-American, and 30 to 40 years of age, but less likely to be married or living with a sex partner compared to nonsmokers. Daily crack users were less likely to be daily injectors but more likely to use alcohol daily when compared to non-crack users and less-than-daily crack smokers. IDUs who smoked crack less than daily were more likely to have injected with needles and syringes used by others. There is an urgent need for additional research on the relationship between drug injection and crack smoking as well as improved HIV risk-reduction interventions that include drug abuse treatment components focusing on issues surrounding crack-cocaine addiction.

Differences in drug use among rural and suburban high school students in Ohio

This exploratory study examines differences in the prevalence of drug use by gender among twelfth grade students (n = 464) in selected rural and suburban high schools in west-central Ohio. The lifetime use of alcohol and other drugs is common among all groups. Proportionally fewer boys in rural schools than boys in suburban schools reported the use of marijuana, inhalants, and LSD, or recent episodes of drunkenness. No statistically significant differences emerged between girls in rural and suburban schools. Afterschool employment practices may help explain the observed differences.

A preliminary evaluation of a modified needle-cleaning intervention using bleach among injection drug users

This study examines an intervention designed to improve needle-cleaning practices among injection drug users (IDUs) in Dayton and Columbus, Ohio, to meet the recommended bleach exposure time of at least 30 seconds. Simulated needle-cleaning practices were observed in offices at baseline and after an intervention at 2 to 4 week and 6-month follow-ups. Descriptive statistics, t-tests, logistic, and multiple regressions were used to examine behavior change and the correlates of safer cleaning practices. At baseline (n = 541), the mean bleach exposure time was 13.8 seconds. At first follow-up (n = 410), the mean bleach contact time (23.4 s) increased significantly (t = 8.59; p < .05). At 6-month follow-up (n = 83), the mean bleach exposure time (21.1 s) also increased significantly (t = 2.98; p < .05). Longer bleach contact time was associated with higher injection frequency and needle transfer at 6-month follow-up. Although mean bleach exposure time increased significantly at both follow-ups, only 30.3% of the IDUs kept bleach in the syringe for at least 30 seconds at 6-month follow-up. Improved interventions are needed.

Needle transfer among injection drug users: a multilevel analysis

OBJECTIVE

The purpose of the study described here is to extend our understanding of needle transfer behaviors among injection drug users (IDUs) by combining both micro and macro variables in a multilevel model.

METHODS

A sample of 8,404 IDUs interviewed at 18 sites of the National Institute on Drug Abuse (NIDA) Cooperative Agreement for AIDS Community-Based Outreach/Intervention Program (COOP) was used for the study. A multilevel model was employed to deal with intraclass correlation in the sample and to evaluate the impact of micro and macro variables on needle transfer among IDUs.

RESULTS

A significant intraclass correlation was detected in the sample. Needle transfer was associated with both the individual characteristics and the features of the social setting in which they were embedded. Some of the micro slopes were fixed, while some varied from site to site, depending on the values of macro variables. The micro intercept and the micro slope of ethnicity vary randomly across social settings, while they are partially determined by macro variables.

CONCLUSION

Considering the intraclass correlation in the data and the effects of contextual features on individual behaviors, multilevel analysis of HIV risk behaviors should be considered when combining data from micro and macro levels (e.g., individual and project site levels).

Factors influencing condom use among heterosexual users of injection drugs and crack cocaine

OBJECTIVES

To study factors that influence the self-reported use of condoms among injection drug users and crack smokers.

STUDY DESIGN

A cross-sectional design was used to collect data from drug-using heterosexual men (n = 247) and women (n = 107).

RESULTS

Participants were largely African American (79.4%), male (69.8%), and unmarried (90.1%). The mean age for men was 39.9 years, 35.5 years for women. Drug user groups consisted of individuals who used both crack cocaine and injection drugs (40.1%), noninjecting crack smokers (33.1%), and non-crack-smoking injection drug users (26.8%). Daily injection drug or crack use was reported by 62.9% of the sample. One third of the sample reported recent vaginal sex with more than one partner. More than 70% of the participants frequently used drugs when having sex. Logistic regression showed that individuals who were high when having vaginal sex were less likely to use condoms than people who were not high (odds ratio [OR] 0.82; 95% confidence interval [CI], 0.68-0.99); individuals whose partners got high when having sex were more likely to report condom use (OR 1.20; 95% CI, 1.01-1.42); individuals were less likely to use condoms when having sex with a main partner (OR 0.40; 95% CI, 0.20-0.80); individuals who believed it was important to use condoms were more likely to use condoms (beta = 0.57, P < 0.00); and people who believed condoms reduced sexual pleasure were less likely to use condoms (beta = -0.53, P < 0.00).

CONCLUSIONS

In addition to being sensitive to partner characteristics, sex risk-reduction interventions targeting users of injection drugs or crack must address the widespread use of psychoactive drugs that occurs immediately before and during sex because such use presents a significant impediment to the employment of safer-sex techniques that rely on condoms. Until such interventions are in place, access to drug abuse treatment is a critical dimension of human immunodeficiency virus and other sexually transmitted disease prevention.

History of sexually transmitted diseases infection, drug-sex behaviors, and the use of condoms among midwestern users of injection drugs and crack cocaine

BACKGROUND AND OBJECTIVES

This study describes self-reported histories of sexually transmitted diseases (STD) with respect to gender and ethnicity and examines the factors that influence the use of condoms among heterosexual users of injection drugs and/or crack cocaine.

STUDY DESIGN

A cross-sectional design was used to interview 1046 active users of illicit drugs living in Columbus and Dayton, Ohio.

RESULTS

STD was common among 29% of the white men, 53.6% of the black men, 55.9% of the white women, and 64.7% of the black women self-reporting previous infection. Among women, stepwise logistic regression showed that cohabitating with a spouse or a sex partner (OR 0.28; 95% CI, 0.06 to 0.77) and exchanging sex for drugs (OR 0.31; 95% CI, 0.11 to 0.88) were associated negatively with always using a condom during vaginal sex in the previous month, whereas exchanging sex for money (OR 4.48; 95% CI, 1.88 to 10.95) was associated positively. Among men, cohabitating with a spouse or a sex partner (OR 0.13; 95% CI, 0.06 to 0.31), having had an STD (OR 0.53; 95% CI, 0.33 to 0.85), and currently using injection drugs (OR 0.52; 95% CI, 0.33 to 0.84) were associated negatively with condom use.

CONCLUSIONS

Users of illicit drugs are at high risk for the acquisition and transmission of STD. More research is needed to understand better the sex practices of users of injection drugs and crack cocaine so that appropriate interventions can be developed.

Usefulness of the health belief model in predicting HIV needle risk practices among injection drug users

A health belief model (HBM) that included the dimensions of perceived susceptibility, seriousness, benefits, barriers, and self-efficacy was employed to predict which injection drug users (IDUs) were engaged in needle-use practices that reduced their risk for contracting the human immunodeficiency virus (HIV). A sample of 118 active IDUs, many of whom also used crack cocaine, responded to interviewer-administered questionnaires that gathered information on their drug-use practices in the last thirty days, as well as their health beliefs. Logistic regression analysis revealed that two health beliefs--perceived self-efficacy (OR = 1.27, 95% CI = 1.04, 1.55) and perceived susceptibility (OR = .82, 95% CI = .71, .94)--were significantly related to safer injection practices. Other predictors of safer injection were black ethnicity (OR = 3.18, 95% CI = 1.19, 8.47) and injection frequency (OR = .99, 95% CI = .98, .99). The results of this study suggest that the HBM has a role to play in risk-reduction programs targeting IDUs.

Reducing HIV needle risk behaviors among injection-drug users in the Midwest: an evaluation of the efficacy of standard and enhanced interventions

This study compares the impact of a standard and an enhanced intervention on the needle-use behaviors reported by injection-drug users (IDUs) living in a low-seroprevalence area in the Midwest. Data on the drug- and needle-use practices of 381 IDUs completing a standard (n = 232) or an enhanced (n = 149) intervention who were followed-up five to nine months after a baseline interview were analyzed using bivariate and multivariate techniques. The results indicate that IDUs who participated in the enhanced intervention reported safer needle practices than standard intervention IDUs at follow-up. In addition, less frequent injectors were much more likely to adopt safer needle-use practices than were daily drug injectors, regardless of intervention track. The results suggest that more intensive interventions have advantages over minimalist efforts--in specific contexts. This finding has important implications for the HIV needle risk-reduction efforts targeting IDUs.

Injection drug users, crack-cocaine users, and human services utilization: an exploratory study

Estimates of the number of people addicted to heroin and cocaine run into the millions. How these drug abusers interact with the social services system is not well understood. To gain insight into the nature and extent of such interactions, an exploratory study was conducted to gather information on the perceptions and utilization of human services by 44 drug abusers not in treatment. Twenty-nine injection drug users and 15 crack-cocaine users participated in focus group sessions and structured interviews. Participants were recruited by indigenous outreach workers in Dayton and Columbus, Ohio. Findings revealed a very high rate of service use by the drug users. The results raise questions about the role and efficacy of the social services system in identifying drug users and addressing their needs. In addition, the findings raise perplexing questions regarding the effectiveness of acquired immune deficiency syndrome risk-reduction efforts among injection drug users and crack-cocaine users.

Drug abuse treatment experience and HIV risk behaviors among active drug injectors in Ohio

This study compares the sociodemographic characteristics and human immunodeficiency virus (HIV) risk behaviors of injection drug users who had received drug abuse treatment in the previous 5 years and those who had not received treatment. The National AIDS Demonstration Research Program database provided 2001 structured interviews, representing Cleveland, Columbus, Cincinnati, and Dayton, Ohio. About 43% of the subjects reported having received treatment in the previous 5 years. Length of involvement with drugs, more frequent injection, more legal problems, and higher levels of HIV risk behaviors were associated with a history of treatment. Incorporating HIV risk reduction education in drug abuse treatment is an urgent priority.

Injection drug users in the Midwest: an epidemiologic comparison of drug use patterns in four Ohio cities

Variations in the drug use patterns of injection drug users (IDUs) can have important implications for public health efforts aimed at reducing drug abuse and the transmission of the human immunodeficiency virus. This article describes and compares the characteristics of IDUs living in four Ohio cities and compares African-American and White IDUs at a statewide level. Data from 2,001 IDUs who were recruited for the National AIDS Demonstration Research project between 1989 and 1991 in Columbus, Cleveland, Cincinnati, and Dayton were compared on a number of variables by city and by ethnicity using descriptive statistics and ANCOVA analysis. Significant differences among IDUs in the four cities exist for the use of alcohol, marijuana, cocaine, crack, heroin, speedball, other opioids, shooting gallery use, "safer" needle practices, treatment history, and self-help participation. Differences by ethnicity emerged on all variables except marijuana use, overall injection frequency, and incarceration experience. The results suggest that dramatic differences exist between African-American and White IDUs, and among IDUs in cities relatively close together, regardless of ethnicity. These findings should be considered when developing policy and programs for prevention and treatment activities targeting IDUs.

Popping and snorting volatile nitrites: a current fad for getting high

In certain social circles a variety of volatile nitrites are being used extensively to expand creativity, stimulate music appreciation, promote a sense of abandon in dancing, and intensify sexual experience. Soon after amyl nitrite (the prototype of this group) became a prescription drug, legally produced substitutes appeared and were sold as room odorizers. Analyses of eight of these substitutes showed them to contain isomers of butyl or amyl alcohol and a corresponding nitrite. The authors describe the context of use of these products and their desired and adverse effects.