Relationships between substance use disorders, 'severe mental illness' and re-arrest in a county detention facility: A 4-year follow-up cohort study.

BACKGROUND: A growing body of literature demonstrates strong association between poor mental health and criminal recidivism, but research from county jails is limited. AIMS: Our aim was to examine the relationship between re-arrest and severe mental illnesses-schizophrenia, bipolar disorder and major depressive disorder-together and separately and with substance use disorders, separately and as comorbid conditions, in a mid-sized county jail cohort in the southeastern United States. METHODS: We examined the full cohort of 8097 individuals who were booked into the County Detention Facility between 31 January 2014 and 31 January 2015. Their incarceration data were merged with data from the local health system to investigate the presence of severe mental illness and substance use disorder diagnoses. Re-arrest data were tracked for 4 years after the index arrest. RESULTS: Approximately 60% of the cohort was re-arrested within 4 years. People with substance use disorders, with or without severe mental illness, had higher re-arrest rates than those with severe mental illness alone or neither diagnosis. Drug-associated arrests did not explain this finding. CONCLUSIONS: Using detailed mental illness diagnosis data with a complete cohort of detained arrestees, we have shown the wide range of need among such individuals. By demonstrating that drug-associated crimes per se do not drive repeated arrest, we underscore a need to examine other factors that promote the cycle of repeated arrest in this population. Each individual requires treatment tailored to their personal psychiatric and criminogenic needs.

Utilizing Bloom's taxonomy to design a substance use disorders course for health professions students.

BACKGROUND: Substance use disorders (SUDs) are a public health problem affecting millions of Americans. Despite their prevalence, there are few health care resources allocated for SUDs treatment. Relatively few health care professionals are exposed to SUDs education in their respective programs, which may be one reason for this resource insufficiency. In hopes of rectifying this gap, the authors developed a SUDs course for health professions students combining classroom learning with practical application to patient care. METHODS: The authors used Bloom's taxonomy of cognitive, affective, and psychomotor learning domains as an educational framework to create numerous opportunities for students to deepen their knowledge, assess their attitudes, and develop their motivational interviewing skills. The primary outcome of the study was a comparison of students' scores on the Substance Abuse Attitude Scale (SAAS) pre- and post-course completion. Secondary outcome was to compare students' self-assessment scores of their patient counseling with residents' assessments of them on the Liverpool Communication Skills Assessment Scale (LCSAS). RESULTS: One hundred twelve students participated in the authors' SUDs course over a 9-month period. Ninety-five students completed both the pre- and post-course SAAS surveys. The total SAAS survey score and individual domain scores for nonmoralizing, treatment optimism, and treatment intervention demonstrated significant improvement post-course. Eighty-nine students completed a motivational interview with a patient. Eighty students had a LCSAS self-assessment paired with a residents' assessment. Mean scores for individual items on the LCSAS for both groups' assessment were approximately 3.5, indicating that students' communication was assessed as "acceptable" to "good." CONCLUSIONS: This study demonstrates that Bloom's taxonomy was a useful educational framework to ensure a systematic development of the authors' SUDs course. Through participation in our course, students touched each of the 3 domains in Bloom's taxonomy. The authors believe their course design may serve as a framework for future SUDs courses.

Phenotypic mapping of metabolic profiles using self-organizing maps of high-dimensional mass spectrometry data.

A metabolic system is composed of inherently interconnected metabolic precursors, intermediates, and products. The analysis of untargeted metabolomics data has conventionally been performed through the use of comparative statistics or multivariate statistical analysis-based approaches; however, each falls short in representing the related nature of metabolic perturbations. Herein, we describe a complementary method for the analysis of large metabolite inventories using a data-driven approach based upon a self-organizing map algorithm. This workflow allows for the unsupervised clustering, and subsequent prioritization of, correlated features through Gestalt comparisons of metabolic heat maps. We describe this methodology in detail, including a comparison to conventional metabolomics approaches, and demonstrate the application of this method to the analysis of the metabolic repercussions of prolonged cocaine exposure in rat sera profiles.

Depression inhibits the anti-inflammatory effects of leisure time physical activity and light to moderate alcohol consumption.

Light to moderate alcohol consumption and leisure time physical activity (LTPA) are independently associated with lower levels of high sensitivity C-reactive protein (CRP), a predictor of cardiometabolic risk. In contrast, depression, ranging from low mood disturbance to major depressive disorder, has been associated with elevated CRP. To test the hypothesis that depression attenuates the anti-inflammatory effects of LTPA and alcohol consumption, the current study tested the moderating effect of severity of depressive symptomatology on the relation of alcohol consumption and LTPA to CRP in 222 healthy adult men and women (18-65 years of age). Given the known effects of gender on inflammation, we also examined the effects of gender on the tested interactions. Depression was assessed using the Beck Depression Inventory. Frequency of alcohol consumption, hours of LTPA per week and other coronary risk/protective factors were assessed via self-report and structured interview. Fasting blood samples were used to measure CRP and lipids. As predicted, the interaction between LTPA and depressive symptomatology was significant (F=5.29, p<.03) such that lower CRP was associated with the combination of decreased depressive symptomatology and increased LTPA. Among those with increased depressive symptoms, increased LTPA was not associated with higher CRP. Similarly, depression interacted with alcohol consumption in predicting CRP in men but not women (F=5.03, p<.008) such that for men light to moderate alcohol consumption was associated with lower CRP but only among those with decreased depressive symptoms. Light to moderate alcohol consumption was not associated with lower CRP in those with increased depressive symptom severity. The pattern of the interactions between anti-inflammatory activities such as light to moderate alcohol consumption and LTPA and psychological distress as indexed by severity of depressive symptomatology suggests an important new avenue for future research.

Reliance on Community Emergency Departments by People Ever Detained in Jail: Retrospective Cross-Sectional Study.

Millions are confined in U.S. jails each year, often with unmet health and social needs. After release, many will visit the emergency department (ED). To illuminate their patterns of ED use, this study linked records from all individuals detained at a Southern urban jail over a 5-year period with health records from a large health care system with three EDs. Over half used the ED at least once, and of those who received care at the health system, 83% visited the ED. Jail-involved people made up 4.1% of the health care system's ED users but 21.3% of its chronic frequent ED users. Frequent ED use was associated with more frequent jail bookings and with co-occurring serious mental illness and substance use disorder. Health systems and jails have a common interest in addressing the needs of this population. Individuals with co-occurring disorders should be prioritized for intervention.

Increasing Naloxone Prescribing in the Emergency Department Through Education and Electronic Medical Record Work-Aids.

BACKGROUND: Emergency department (ED) visits for opioid overdose continue to rise. Evidence-based harm reduction strategies for opioid use disorder (OUD), such as providing home naloxone, can save lives, but ED implementation remains challenging. METHODS: The researchers aimed to increase prescribing of naloxone to ED patients with OUD and opioid overdose by employing a model for improvement methodology, a multidisciplinary team, and high-reliability interventions. Monthly naloxone prescribing rates among discharged ED patients with opioid overdose and OUD-related diagnoses were tracked over time. Interventions included focused ED staff education on OUD and naloxone, and creation of electronic medical record (EMR)-based work-aids, including a naloxone Best Practice Advisory (BPA) and order set. Autoregressive interrupted time series was used to model the impact of these interventions on naloxone prescribing rates. The impact of education on ED staff confidence and perceived barriers to prescribing naloxone was measured using a published survey instrument. RESULTS: After adjusting for education events and temporal trends, ED naloxone BPA and order set implementation was associated with a significant immediate 21.1% increase in naloxone prescribing rates, which was sustained for one year. This corresponded to increased average monthly prescribing rates from 1.5% before any intervention to 28.7% afterward. ED staff education had no measurable impact on prescribing rates but was associated with increased nursing perceived importance and increased provider confidence in prescribing naloxone. CONCLUSIONS: A significant increase in naloxone prescribing rates was achieved after implementation of high-reliability EMR work-aids and staff education. Similar interventions may be key to wider ED staff engagement in harm reduction for patients with OUD.

Aversive effects of ethanol in adolescent versus adult rats: potential causes and implication for future drinking.

BACKGROUND: Many people experiment with alcohol and other drugs of abuse during their teenage years. Epidemiological evidence suggests that younger initiates into drug taking are more likely to develop problematic drug seeking behavior, including binge and other high-intake behaviors. The level of drug intake for any individual depends on the balance of rewarding and aversive effects of the drug in that individual. Multiple rodent studies have demonstrated that aversive effects of drugs of abuse are reduced in adolescent compared to adult animals. In this study, we addressed 2 key questions: First, do reduced aversive effects of ethanol in younger rats correlate with increased ethanol consumption? Second, are the reduced aversive effects in adolescents attributable to reduced sensitivity to ethanol's physiologic effects? METHODS: Adolescent and adult rats were tested for ethanol conditioned taste aversion (CTA) followed by a voluntary drinking period, including postdeprivation consumption. Multivariate regression was used to assess correlations. In separate experiments, adolescent and adult rats were tested for their sensitivity to the hypothermic and sedative effects of ethanol, and for blood ethanol concentrations (BECs). RESULTS: We observed that in adolescent rats but not adults, taste aversion was inversely correlated with postdeprivation consumption. Adolescents also exhibited a greater increase in consumption after deprivation than adults. Furthermore, the age difference in ethanol CTA was not attributable to differences in hypothermia, sedation, or BECs. CONCLUSIONS: These results suggest that during adolescence, individuals that are insensitive to aversive effects are most likely to develop problem drinking behaviors. These results underscore the importance of the interaction between developmental stage and individual variation in sensitivity to alcohol.

Novelty-induced locomotion is positively associated with cocaine ingestion in adolescent rats; anxiety is correlated in adults.

The present studies assessed the roles of sex, age, novelty-seeking and plus-maze behavior on cocaine drinking in rats. Cocaine/saccharin solution was available in three daily, 5-hour sessions then a saccharin-only solution was also available in following sessions. In the one-bottle drinking phase, early and late adolescent males, post-natal day 28 (PN28) and PN42, consumed more cocaine/saccharin solution than young adults (PN65), but females did not exhibit significant age differences. Adolescents of both sexes consumed more cocaine/saccharin than adults during choice drinking. Saccharin availability in the two-bottle trials decreased cocaine/saccharin consumption in PN28 and PN65 rats. After a drug-free period, cocaine-stimulated locomotion was lower in cocaine/saccharin drinking than saccharin-only males, indicating tolerance. We tested the hypothesis that individual differences in pre-screened behavioral traits would correlate with cocaine/saccharin consumption in PN28 and PN65 male rats. High locomotor responses to novelty were associated with greater cocaine/saccharin drinking in adults in one-bottle sessions. In the subsequent choice drinking phase, correlations were age-specific. Adolescents with high novelty-induced locomotion and adults that spent less time on open arms of the elevated plus-maze drank more cocaine/saccharin. Thus, behavioral phenotypes correlated with individual differences in cocaine/saccharin consumption in an age-related manner.

Early ethanol consumption predicts relapse-like behavior in adolescent male rats.

BACKGROUND: Alcohol abuse disorders emerge over time with repeated consumption of ethanol, but not all ethanol drinkers develop these disorders. There are pre-existing characteristics that indicate which drinkers are most likely to abuse alcohol. Adolescence, novelty seeking, and high stress reactivity are among the characteristics of the most vulnerable individuals. In addition, an individual's response to his or her first exposure to the drug influences future consumption. We assessed an array of behavioral and hormonal characteristics in adolescent (28-day-old) male rats before exposure to ethanol, and then determined which rats were most prone to high levels of alcohol drinking. METHODS: The assessments consisted of measures of anxiety (elevated plus maze), response to novelty (open field locomotion, novel object exploration), and circulating corticosterone levels after mild restraint and after the elevated plus maze task. After this test battery, the rats were placed in lickometer cages nightly (5 pm to 9 am) for evaluation of fluid consumption. Rats were first habituated to the cages with water in the lickometer bottles, and then given 10% (v/v) ethanol for 3 nights as the only available fluid. After this forced ethanol exposure, the rats were allowed to choose between 8% ethanol and water for 10 consecutive nights. After 2 nights of abstinence, the rats were again placed in the lickometer cages and given a choice between 8% ethanol and water to assess ethanol consumption in response to alcohol deprivation, a measure of relapse-like behavior. RESULTS: Ethanol consumption on the third day of forced consumption was significantly correlated with ethanol consumption on days 8 to 10 of the choice phase, which in turn was significantly correlated to relapse-like consumption. Preference for ethanol was also significantly correlated with early consumption. Novel object exploration, open field activity, open arm time in the elevated plus maze, initial water consumption, and circulating corticosterone levels did not significantly predict deprivation-stimulated consumption. CONCLUSIONS: These results suggest that consumption during early exposure to ethanol establishes a pattern leading to development of increased alcohol consumption and preference in adolescent male rats. In addition, they represent an animal model of the well-described observation that humans who consume large quantities of ethanol during early exposure are the most likely to repeat heave drinking behavior. Furthermore, early consumption is distinct from novelty seeking, anxiety, and stress hormone levels which are also thought to contribute to vulnerability to alcoholism.

The Emergency Department as an Opportunity for Naloxone Distribution.

INTRODUCTION: Substance use disorders, including opioid use disorders, are a major public health concern in the United States. Between 2005 and 2014, the rate of opioid-related emergency department (ED) visits nearly doubled, from 89.1 per 100,000 persons in 2005 to 177.7 per 100,000 persons in 2014. Thus, the ED presents a distinctive opportunity for harm-reduction strategies such as distribution of naloxone to patients who are at risk for an opioid overdose. METHODS: We conducted a systematic review of all existing literature related to naloxone distribution from the ED. We included only those articles published in peer-reviewed journals that described results relating to naloxone distribution from the ED. RESULTS: Of the 2,286 articles we identified from the search, five met the inclusion criteria and had direct relevance to naloxone distribution from the ED setting. Across the studies, we found variation in the methods of implementation and evaluation of take-home naloxone programs in the ED. In the three studies that attempted patient follow-up, success was low, limiting the evidence for the programs' effectiveness. Overall, in the included studies there is evidence that distributing take-home naloxone from the ED has the potential for harm reduction; however, the uptake of the practice remained low. Barriers to implementation included time allocated for training hospital staff and the burden on workflow. CONCLUSION: This systematic review of the best evidence available supports the ED as a potential setting for naloxone distribution for overdose reversal in the community. The variability of the implementation methods across the studies highlights the need for future research to determine the most effective practices.

Extracellular-signal regulated kinase 1-dependent metabotropic glutamate receptor 5-induced long-term depression in the bed nucleus of the stria terminalis is disrupted by cocaine administration.

The bed nucleus of the stria terminalis (BNST) is a key component of the CNS stress and reward circuit. Synaptic plasticity in this region could in part underlie the persistent behavioral alterations in generalized anxiety and addiction. Group I metabotropic glutamate receptors (mGluRs) have been implicated in stress, addiction, and synaptic plasticity, but their roles in the BNST are unknown. We find that activation of group I mGluRs in the dorsal BNST induces depression of excitatory synaptic transmission through two distinct mechanisms. First, a combined activation of group I mGluRs (mGluR1 and mGluR5) induces a transient depression that is cannabinoid 1 receptor dependent. Second, as with endocannabinoid-independent group I mGluR long-term depression (LTD) in the adult hippocampus, we find that activation of mGluR5 induces an extracellular signal-regulated kinase (ERK)-dependent LTD. Surprisingly, our data demonstrate that this LTD requires the ERK1 rather than ERK2 isoform, establishing a key role for this isoform in the CNS. Finally, we find that this LTD is dramatically reduced after multiple exposures but not a single exposure to cocaine, suggesting a role for this form of plasticity in the actions of psychostimulants on anxiety and reward circuitries and their emergent control of animal behavior.

Differential anxiogenic, aversive, and locomotor effects of THC in adolescent and adult rats.

RATIONALE: Unpleasant side effects of drugs of abuse often limit their repeated use; however, such effects may be attenuated in adolescents compared to adults. OBJECTIVES: We investigated whether the anxiogenic, aversive, or locomotor effects of delta-9-tetrahydrocannabinol (THC) differ between adolescent and adult rats. METHODS: We used the elevated plus maze (EPM) and light-dark tests of anxiety, the conditioned taste aversion and conditioned place aversion (CPA) tests of generalized aversion, and measures of stress hormone levels in serum to examine effects of THC in adolescent and adult rats. Locomotor activity was also recorded in the EPM, light-dark task, and CPA association sessions. RESULTS: In the EPM and light-dark tasks, THC was anxiogenic in both age groups, but the drug was more anxiogenic in adults than in adolescents. In the place and taste aversion tasks, THC was aversive in both ages, and at 1.25 and 5 mg/kg, was more aversive in adults than in adolescents. The locomotor response to THC, as measured in the anxiety tasks and CPA, affected adults more than adolescents. Multiple measures revealed a locomotor-decreasing effect in adults, whereas some measures suggested a small locomotor-increasing effect in adolescent rats. CONCLUSIONS: These results suggest that THC can have greater anxiogenic, aversive, and locomotor-reducing effects in adult rats than in adolescent rats. These findings suggest an explanation for reduced marijuana use in adult humans compared to teenagers.

Behavioral Inefficiency on a Risky Decision-Making Task in Adulthood after Adolescent Intermittent Ethanol Exposure in Rats.

Adolescence is a period of development in neural circuits that are critical for adult functioning. There is a relationship between alcohol exposure and risky decision-making, though the enduring effects of adolescent ethanol exposure on risky decision-making in adulthood have not been fully explored. Studies using positive reinforcement have shown that adolescent intermittent ethanol (AIE) exposure results in higher levels of risky decision-making in adulthood, but the effects of AIE on punishment-mediated decision-making have not been explored. Adolescent rats were exposed to AIE or saline vehicle across a 16-day period, and then allowed to mature into adulthood. They were then trained to lever press for food reward and were assessed for risky decision-making by pairing increased levels of food reward with the probability of footshock punishment. AIE did not alter punishment-mediated risky decision-making. However, it did result in a significant increase in the delay to lever pressing. This finding is consistent with previous reports, using other behavioral tasks, which show decreased behavioral efficiency in adulthood after AIE. These findings indicate that AIE increases behavioral inefficiency, but not punishment-mediated risk-taking, in adulthood. Thus they contribute to a more nuanced understanding of the long-term effects of AIE on adult behavior.

An Interprofessional Course on Substance Use Disorders for Health Professions Students.

PROBLEM: Substance use disorders (SUDs) affect millions of Americans. Nevertheless, there is insufficient health care resource allocation for these patients. One reason may be the lack of education and training about SUDs in health professions programs. APPROACH: The authors developed a required, interprofessional SUDs course for health professions students completing a one-month psychiatry clerkship within the Duke University Health System starting in November 2015. Students participated in six 1-hour class sessions led by an interdisciplinary faculty. Sessions focused on core areas in SUDs education and used either a lecture with discussion or a small-group team-based learning format. Students completed one motivational interview, attended a 12-step recovery meeting, and wrote a reflection paper. On the first and last day of the clerkship, students measured their attitudes toward individuals with SUDs using the Substance Abuse Attitude Scale (SAAS) and toward interprofessionalism using the Interprofessional Attitudes Scale (IPAS). OUTCOMES: Seventy-one students participated in the course from November 2015 to May 2016. Fifty-nine (83%) students had paired pre- and postcourse SAAS and IPAS data. On the SAAS, students showed significant improvement in their median total score and nonmoralizing, treatment optimism, and treatment intervention scores. On the IPAS, students showed significant improvement in their median score on the teamwork, roles, and responsibilities domain. NEXT STEPS: The authors will continue to assess the course. Starting in academic year 2016-2017, the course will include four additional elements, and beginning in July 2016, accelerated bachelor of science in nursing students will participate in the course.

Cocaine self-administration reduces excitatory responses in the mouse nucleus accumbens shell.

Drugs of abuse affect behavior by altering neuronal communication within the brain. Previous research examining the effects of intraperitoneally administered cocaine has revealed that cocaine alters excitatory glutamatergic signaling, both directly through regulation of synaptic function, and indirectly through regulation of cellular excitability in areas of the drug reward circuitry such as the nucleus accumbens (NAcc) and ventral tegmental area. We have now extended these findings by testing the hypothesis that self-administration of cocaine might elicit similar alterations in excitatory signaling in the NAcc shell. We observed that cocaine self-administration reduces synaptically evoked excitatory responses recorded extracellularly in the NAcc shell compared to saline self-administration. This alteration was not accompanied by alterations in paired pulse ratio of synaptically evoked responses or in potentiation of these responses by application of the adenylyl cyclase activator forskolin. This reduction in glutamatergic signaling may be one mechanism by which cocaine exerts its long-term behavioral effects.

Adolescent rats are protected from the conditioned aversive properties of cocaine and lithium chloride.

In humans, most drug use is initiated during adolescence and adolescent users are more likely to become drug-dependent than adult users. Repeated, high levels of use are required for the transition from use to addiction. Individual levels of drug use are thought to result from a balance between the pleasant or rewarding and the unpleasant or aversive properties of the drug. Repeated high levels of drug use are required for the transition from drug use to dependence. We hypothesized that diminished aversive effects of drugs of abuse during adolescence might be one reason for higher rates of use and addiction during this phase. We therefore tested adolescent and adult CD rats in single-dose cocaine conditioned taste aversion (CTA) at a range of doses (10-40 mg/kg), and examined whether various behavioral markers of addiction vulnerability were correlated to outcome in cocaine CTA. We found that adolescents are indeed less susceptible to cocaine CTA. In fact, age was the predominant predictor of CTA outcome, predominating over measures of novelty-seeking, anxiety, and stress hormone levels, which are all known to be related to drug intake in other models. Furthermore, we found that adolescent rats are also less susceptible to conditioned taste aversion to a low dose of a non-addictive substance, lithium chloride. These results suggest that one explanation for elevated drug use and addiction among adolescents is reduced aversive or use-limiting effects of the drugs. This contributes to our understanding of why adolescence is a particularly vulnerable period for development of drug abuse.

Effects of periadolescent versus adult cocaine exposure on cocaine conditioned place preference and motor sensitization in mice.

RATIONALE: Age of initial exposure to addictive substances is inversely proportional to risk of developing drug dependence. There is debate, however, as to whether intake at a young age causes dependency or whether young people who experiment with addictive substances are predisposed to dependency by other factors. OBJECTIVES. We tested the relationship between cocaine exposure at two different ages in mice and the development of subsequent drug-seeking behavior to test for age-specific exposure effects. METHODS: We performed dose-response analysis of cocaine conditioned place preference (CPP) and locomotor activity in periadolescent and adult C57Bl/6J mice. In addition, we pretreated periadolescent and adult C57Bl/6J mice with cocaine or saline in the home cage or a drug-associated context, and then examined their behavior in a biased CPP procedure in adulthood. RESULTS: Dose-response relationships were similar between the two age groups. In the pretreatment experiments, we observed locomotor sensitization during the pretreatment in periadolescent but not adult mice. We also observed an enhanced aversion to the non-preferred side of the chamber in periadolescent mice compared to adult mice, which was alleviated by cocaine association with that side. Third, we observed that after further conditioning in adulthood, there were no pretreatment-specific effects. CONCLUSIONS: Our results are consistent with a "vulnerable brain" hypothesis for responses to cocaine based on our findings that periadolescent mice exhibit greater locomotor sensitization to cocaine, and greater baseline anxiety responses that are alleviated by cocaine exposure compared to adult mice.

Race differences in the relation of vitamins A, C, E, and ß-carotene to metabolic and inflammatory biomarkers.

Using archival data, we conducted a secondary analysis to examine race differences in the relation of serum vitamins A, C, E and ß-carotene to insulin resistance (IR), fasting insulin and glucose, high sensitivity C-reactive protein (hs-CRP), and leukocyte count in 176 non-smoking, healthy, white, and African American (AA) adults aged 18 to 65 years (48% women, 33% AA). We hypothesized that micronutrient concentrations would be associated with early risk markers of cardiometabolic diseases in a race-dependent manner. Fasting blood samples were analyzed for micronutrients, insulin, glucose, hs-CRP, and leukocyte count. Insulin resistance was estimated using the homeostatic model assessment. After adjusting for age, body mass index, gender, educational level, use of vitamin supplements, alcohol intake, leisure time physical activity, menopausal status, and total cholesterol, we observed that ß-carotene was significantly associated with insulin resistance and fasting insulin in a race-dependent manner. Among AA, lower ß-carotene levels were associated with higher estimates of insulin resistance and fasting insulin; whereas, these same associations were not significant for whites. Race also significantly moderated the relation of vitamin C to leukocyte count, with lower vitamin C being associated with higher leukocyte count only in AA but not whites. For all subjects, lower ß-carotene was associated with higher hs-CRP. In AA, but not whites, lower levels of ß-carotene and vitamin C were significantly associated with early risk markers implicated in cardiometabolic conditions and cancer. Whether or not lower levels of micronutrients contribute uniquely to racial health disparities is a worthwhile aim for future research.