A latent class analysis of drug and substance use patterns among patients treated in emergency departments for suspected drug overdose

Latent class analysis of emergency department patients engaged in telehealth peer recovery support services and associations of identified classes with post-discharge outcomes

BACKGROUND

People with substance use disorders (SUDs) frequently use emergency department (ED) services. Despite evidence demonstrating that post-discharge SUD treatment linkage effectively reduces the number of ED re-presentations, relatively few hospitals have implemented interventions to identify and connect patients with SUDs to appropriate care. ED-based peer recovery support specialist (PRSS) interventions have emerged as a promising approach for hospitals, but more research is needed to understand the extent to which these interventions meet the needs of patients who present to the ED for different reasons and with various underlying concerns.

METHOD

A retrospective cohort analysis used data from a telehealth PRSS program in 15 EDs within one Indiana hospital system. The study included 2950 ED patients who engaged with telehealth PRSS services between September 2018 and September 2021. Latent class analysis identified patterns of patient characteristics associated with post-discharge PRSS engagement and ED re-presentations. Covariate predictors and distal outcomes were assessed to examine the associations between class membership, demographic factors, and patient outcomes.

RESULTS

The study team selected a six-class model as the best fit for the data. Class 1, representing patients with opioid use disorder and mental health diagnoses who presented to the ED for an opioid overdose, was used as the reference class for all other statistical tests. Multinomial logistic regression analysis demonstrated significant associations between covariate predictors, outcomes, and class membership. Regression results also demonstrate PRSSs had greater success contacting patients with prior year ED use and patients with a successful post-discharge PRSS contact were less likely to re-present to the ED.

CONCLUSION

Results highlight the heterogeneity of patients with SUDs and emphasize the need for tailored interventions to address patient-specific needs more effectively. They also provide support for the perceived utility of PRSS engagement for ED patients.

Longitudinal polysubstance use patterns and non-fatal overdose: A repeated measures latent class analysis

BACKGROUND

Polysubstance use (PSU) is common among people who use opioids (PWUO) and has been associated with drug-related harms. We aimed to identify latent longitudinal PSU classes among a cohort of PWUO and characterize non-fatal overdose risks among different sub-classes over time.

METHODS

We used longitudinal data (2005-2018) from three ongoing prospective cohorts of people who use drugs in Vancouver, Canada. The primary outcome of interest was self-reported non-fatal overdose during the past six months. The primary exposure of interest was longitudinal PSU patterns among PWUO, obtained from repeated measures latent class analysis (RMLCA) of weekly substance use-related outcome indicators. Multivariable generalized estimating equations models were built to assess the association between latent PSU class membership and non-fatal overdose, adjusting for potential sociodemographic, behavioural, and structural confounders.

RESULTS

2627 PWUO were included in the analysis, and 1094 (41.6 %) had experienced at least one non-fatal overdose during the study period. RMLCA revealed five distinct latent longitudinal PSU classes, including low/infrequent use (Class 1; 30 %), primarily opioid and methamphetamine use (Class 2; 22 %), primarily cannabis use (Class 3; 15 %), primarily opioid and crack use (Class 4; 29 %), and frequent PSU (Class 5; 4 %). In comparison with Class 1 (low), membership in all latent PSU classes except Class 3 (cannabis) was associated with increased odds of non-fatal overdose: Class 2 (opioids + meth) vs. Class 1 (Adjusted odds ratios [aOR] = 2.20, 95 % confidence intervals [CI]: 1.51-3.22), Class 4 (opioids + crack) vs. Class 1 (aOR = 1.06, 95 % CI: 0.85-1.33), and Class 5 (frequent) vs. Class 1 (aOR = 2.39, 95 % CI: 1.92-2.97).

CONCLUSION

Our findings highlighted the heterogeneous characteristics of PWUO in terms of patterns of PSU and non-fatal overdose risk. The diverse nature of PWUO and the potential additive or multiplicative impact of using several substances on overdoses should be reflected across the substance use treatment continuum and care provision.

Examining the benefit of a higher maintenance dose of extended-release buprenorphine in opioid-injecting participants treated for opioid use disorder

BACKGROUND

BUP-XR (SUBLOCADE®) is the first buprenorphine extended-release subcutaneous injection approved in the USA for monthly treatment of moderate-to-severe opioid use disorder (OUD). Among patients with OUD, those who inject or use high doses of opioids likely require higher doses of buprenorphine to maximize treatment efficacy. The objective of this analysis was to compare the efficacy and safety of 100-mg versus 300-mg maintenance doses of BUP-XR in OUD patients who inject opioids.

METHODS

This was a secondary analysis of a randomized, double-blind, placebo-controlled study in which adults with moderate or severe OUD received monthly injections of BUP-XR (2 × 300-mg doses, then 4 × 100-mg or 300-mg maintenance doses) or placebo for 24 weeks. Abstinence was defined as opioid-negative urine drug screens combined with negative self-reports collected weekly. Each participant's percentage abstinence was calculated after the first, second, and third maintenance doses in opioid-injecting and non-injecting participants. The proportion of participants achieving opioid abstinence in each group was also calculated weekly. Treatment retention rate following the first maintenance dose was estimated for opioid-injecting participants with Kaplan-Meier method. Risk-adjusted comparisons were made via inverse propensity weighting using propensity scores. Buprenorphine plasma concentration-time profiles were compared between injecting and non-injecting participants. The percentages of participants reporting treatment-emergent adverse events were compared between maintenance dose groups within injecting and non-injecting participants separately.

RESULTS

BUP-XR 100-mg and 300-mg maintenance doses were equally effective in non-injecting participants. However, in opioid-injecting participants, the 300-mg maintenance dose delivered clinically meaningful improvements over the 100-mg maintenance dose for treatment retention and opioid abstinence. Exposure-response analyses confirmed that injecting participants would require higher buprenorphine plasma concentrations compared to non-injecting opioid participants to achieve similar efficacy in terms of opioid abstinence. Importantly, both 100- and 300-mg maintenance doses had comparable safety profiles, including hepatic safety events.

CONCLUSIONS

These analyses show clear benefits of the 300-mg maintenance dose in injecting participants, while no additional benefit was observed in non-injecting participants relative to the 100-mg maintenance dose. This is an important finding as opioid-injecting participants represent a high-risk and difficult-to-treat population. Optimal buprenorphine dosing in this population might facilitate harm reduction by improving abstinence and treatment retention.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02357901.

The impact of polysubstance use patterns on engagement of substance use disorder treatment among emergency department patients at high risk of opioid overdose

Background

Substance use patterns are diverse, and multiple substances are often involved in fatal and nonfatal overdoses. Additionally, polysubstance use is associated with greater difficulty accessing and remaining in substance use disorder (SUD) treatment. The aim of this study was to identify substance use patterns and determine their association with SUD treatment engagement among emergency department (ED) patients at risk of opioid overdose.

Methods

This was a sub-analysis of a randomized controlled trial comparing two behavioral interventions for individuals at two EDs in Rhode Island from 2018 to 2021. Past six-month substance use frequency for eight substances plus injection drug use was self-reported at trial enrollment, and SUD treatment engagement within 90 days after enrollment was obtained using administrative data linkages. Latent class analysis identified substance use patterns and multivariable log-binomial models estimated the association with SUD treatment engagement.

Results

Among 607 participants, there were four substance use patterns: 1) low reported use (n = 295), 2) frequent injection and heroin use (n = 131), 3) high frequency broad polysubstance use (n = 62), and 4) low frequency broad polysubstance use (n = 119). Compared to participants with the low reported use pattern, those with the frequent injection and heroin pattern had a greater likelihood of SUD treatment engagement (adjusted risk ratio = 1.28; 95% confidence interval = 1.02-1.61).

Conclusions

Distinct and meaningful polysubstance use patterns showed differential SUD treatment engagement after ED discharge. Nuanced relationships between substance use patterns and treatment highlight the necessity for tailored harm reduction, treatment, and recovery services.

Differential risks of syringe service program participants in Central Ohio: a latent class analysis

BACKGROUND

Significant heterogeneity exists among people who use drugs (PWUD). We identify distinct profiles of syringe service program (SSP) clients to (a) evaluate differential risk factors across subgroups and (b) inform harm reduction programming.

METHODS

Latent class analysis (LCA) was applied to identify subgroups of participants (N = 3418) in a SSP in Columbus, Ohio, from 2019 to 2021. Demographics (age, sex, race/ethnicity, sexual orientation, housing status) and drug use characteristics (substance[s] used, syringe gauge, needle length, using alone, mixing drugs, sharing supplies, reducing use, self-reported perceptions on the impact of use, and treatment/support resources) were used as indicators to define latent classes. A five-class LCA model was developed, and logistic regression was then employed to compare risk factors at program initiation and at follow-up visits between latent classes.

RESULTS

Five latent classes were identified: (1) heterosexual males using opioids/stimulants with housing instability and limited resources for treatment/support (16.1%), (2) heterosexual individuals using opioids with stable housing and resources for treatment/support (33.1%), (3) individuals using methamphetamine (12.4%), (4) young white individuals using opioids/methamphetamine (20.5%), and (5) females using opioids/cocaine (17.9%). Class 2 served as the reference group for logistic regression models, and at the time of entry, class 1 was more likely to report history of substance use treatment, overdose, HCV, sharing supplies, and mixing drugs, with persistently higher odds of sharing supplies and mixing drugs at follow-up. Class 3 was more likely to report history of overdose, sharing supplies, and mixing drugs, but outcomes at follow-up were comparable. Class 4 was the least likely to report history of overdose, HCV, and mixing drugs, but the most likely to report HIV. Class 5 was more likely to report history of substance use treatment, overdose, HCV, sharing supplies, and mixing drugs at entry, and higher reports of accessing substance use treatment and testing positive for HCV persisted at follow-up.

CONCLUSIONS

Considerable heterogeneity exists among PWUD, leading to differential risk factors that may persist throughout engagement in harm reduction services. LCA can identify distinct profiles of PWUD accessing services to tailor interventions that address risks, improve outcomes, and mitigate disparities.

Patterns of opioid use behaviors among patients seen in the emergency department: Latent class analysis of baseline data from the POINT pragmatic trial

INTRODUCTION

The nation's overdose epidemic has been characterized by increasingly potent opioids resulting in more emergency department (ED) encounters over time. ED-based opioid use interventions are growing in popularity; however, they tend to treat people who use opioids as a homogenous population. The current study sought to understand heterogeneity among people who use opioids who encounter the ED by identifying qualitatively different subgroups among participants in an opioid use intervention clinical trial at baseline and examining associations between subgroup membership and multiple correlates.

METHODS

Participants were from a larger pragmatic clinical trial of the Planned Outreach, Intervention, Naloxone, and Treatment (POINT) intervention (n = 212; 59.2 % male, 85.3 % Non-Hispanic White, mean age = 36.6 years). The study employed latent class analysis (LCA) using five indicators of opioid use behavior: preference for opioids, preference for stimulants, usually use drugs alone, injection drug use, and opioid-related problem at ED encounter. Correlates of interest included participants' demographics, prescription histories, health care contact histories, and recovery capital (e.g., social support, naloxone knowledge).

RESULTS

The study identified three classes: (1) noninjecting opioid preferers, (2) injecting opioid and stimulant preferers, and (3) social nonopioid preferers. We identified limited significant differences in correlates across the classes: differences existed for select demographics, prescription histories, and recovery capital but not for health care contact histories. For example, members of Class 1 were the most likely to be a race/ethnicity other than non-Hispanic White, oldest on average, and most likely to have received a benzodiazepine prescription, whereas members of Class 2 had the highest average barriers to treatment and members of Class 3 were the least likely to have been diagnosed with a major mental health illness and had the lowest average barriers to treatment.

CONCLUSIONS

LCA identified distinct subgroups among POINT trial participants. Knowledge of such subgroups assists with the development of better-targeted interventions and can help staff to identify the most appropriate treatment and recovery pathways for patients.

Association of polysubstance use disorder with treatment quality among Medicaid beneficiaries with opioid use disorder

INTRODUCTION

The opioid crisis is transitioning to a polydrug crisis, and individuals with co-occurring substance use disorder (SUDs) often have unique clinical characteristics and contextual barriers that influence treatment needs, engagement in treatment, complexity of treatment planning, and treatment retention.

METHODS

Using Medicaid data for 2017-2018 from four states participating in a distributed research network, this retrospective cohort study documents the prevalence of specific types of co-occurring SUD among Medicaid enrollees with an opioid use disorder (OUD) diagnosis, and assesses the extent to which different SUD presentations are associated with differential patterns of MOUD and psychosocial treatments.

RESULTS

We find that more than half of enrollees with OUD had a co-occurring SUD, and the most prevalent co-occurring SUD was for "other psychoactive substances", indicated among about one-quarter of enrollees with OUD in each state. We also find some substantial gaps in MOUD treatment receipt and engagement for individuals with OUD and a co-occurring SUD, a group representing more than half of individuals with OUD. In most states, enrollees with OUD and alcohol, cannabis, or amphetamine use disorder are significantly less likely to receive MOUD compared to enrollees with OUD only. In contrast, enrollees with OUD and other psychoactive SUD were significantly more likely to receive MOUD treatment. Conditional on MOUD receipt, enrollees with co-occurring SUDs had 10 % to 50 % lower odds of having a 180-day period of continuous MOUD treatment, an important predictor of better patient outcomes. Associations with concurrent receipt of MOUD and behavioral counseling were mixed across states and varied depending on co-occurring SUD type.

CONCLUSIONS

Overall, ongoing progress toward increasing access to and quality of evidence-based treatment for OUD requires further efforts to ensure that individuals with co-occurring SUDs are engaged and retained in effective treatment. As the opioid crisis evolves, continued changes in drug use patterns and populations experiencing harms may necessitate new policy approaches that more fully address the complex needs of a growing population of individuals with OUD and other types of SUD.

Drug Overdose Patterns Among Emergency Department Patients at an Academic Hospital in Jeddah

Background Drug overdose is a significant healthcare issue and remains a common phenomenon in the emergency department (ED). The incidents have increased over the last few years worldwide. There are a few studies about drug overdose in Saudi Arabia in general and Jeddah city specifically. We aimed to describe the pattern of drug overdoses in the emergency department at an academic hospital in Jeddah between 2015-2022. Methodology A retrospective record review study was done in 2022 at an academic hospital in Jeddah between 2015-2021, where charts were reviewed for all reported patients presenting to the ED with drug overdose, including all ages and both genders. A careful review of their medical records, data collection, and processing was done using Google Forms (Google, Mountain View, California) and Microsoft Excel (Microsoft, Redmond, Washington), respectively. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 26 software (IBM Inc. Armonk, New York). Results Seventy-eight patients were identified, meeting the criteria from the medical records. Most of the patients were children under 12 years of age. Most patients were clinically stable when they arrived at the emergency department. Gastrointestinal symptoms were the most common clinical presentations, followed by drowsiness, while some patients were non-symptomatic. Analgesics and nonsteroidal were the most common causes of drug overdose. Conclusion We concluded from this limited study that the most commonly used causative agent in drug overdoses was nonsteroidal and analgesics. Moreover, children younger than 12 years of age constituted the majority of drug overdose patients, and accidental overdose represented the majority of cases. Therefore, it is important to increase public awareness of proper child supervision and keep drugs out of children's reach. More research using larger and more representative data is needed to identify patterns of drug overdose in the community.

Current Perspectives on Selective Dopamine D3 Receptor Antagonists/Partial Agonists as Pharmacotherapeutics for Opioid and Psychostimulant Use Disorders

Over three decades of evidence indicate that dopamine (DA) D3 receptors (D3R) are involved in the control of drug-seeking behavior and may play an important role in the pathophysiology of substance use disorders (SUD). The expectation that a selective D3R antagonist/partial agonist would be efficacious for the treatment of SUD is based on the following key observations. First, D3R are distributed in strategic areas belonging to the mesolimbic DA system such as the ventral striatum, midbrain, and ventral pallidum, which have been associated with behaviors controlled by the presentation of drug-associated cues. Second, repeated exposure to drugs of abuse produces neuroadaptations in the D3R system. Third, the synthesis and characterization of highly potent and selective D3R antagonists/partial agonists have further strengthened the role of the D3R in SUD. Based on extensive preclinical and preliminary clinical evidence, the D3R shows promise as a target for the development of pharmacotherapies for SUD as reflected by their potential to (1) regulate the motivation to self-administer drugs and (2) disrupt the responsiveness to drug-associated stimuli that play a key role in reinstatement of drug-seeking behavior triggered by re-exposure to the drug itself, drug-associated environmental cues, or stress. The availability of PET ligands to assess clinically relevant receptor occupancy by selective D3R antagonists/partial agonists, the definition of reliable dosing, and the prospect of using human laboratory models may further guide the design of clinical proof of concept studies. Pivotal clinical trials for more rapid progression of this target toward regulatory approval are urgently required. Finally, the discovery that highly selective D3R antagonists, such as R-VK4-116 and R-VK4-40, do not adversely affect peripheral biometrics or cardiovascular effects alone or in the presence of oxycodone or cocaine suggests that this class of drugs has great potential in safely treating psychostimulant and/or opioid use disorders.

Can cannabis kill? Characteristics of deaths following cannabis use in England (1998-2020)

BACKGROUND

Cannabis is the most widely used illegal drug but is rarely considered a causal factor in death.

AIMS

This study aimed to understand trends in deaths in England where cannabinoids were detected at post-mortem, and to evaluate the clinical utility of post-mortem cannabinoid concentrations in coronial investigations.

METHODS

Deaths with cannabinoid detections reported to the National Programme on Substance Abuse Deaths (NPSAD) were extracted and analysed.

RESULTS

From 1998 to 2011, on average 7% of all cases reported to NPSAD had a cannabinoid detected (n = 110 deaths per year), rising to 18% in 2020 (n = 350). Death following cannabis use alone was rare (4% of cases, n = 136/3455). Traumatic injury was the prevalent underlying cause in these cases (62%, n = 84/136), with cannabis toxicity cited in a single case. Polydrug use was evident in most cases (96%, n = 3319/3455), with acute drug toxicity the prevalent underlying cause (74%, n = 2458/3319). Cardiac complications were the most cited physiological underlying cause of death (4%, n = 144/3455). The median average Δ9-tetrahydrocannabinol post-mortem blood concentrations were several magnitudes lower than previously reported median blood concentrations in living users (cannabis alone: 4.3 µg/L; cannabis in combination with other drugs: 3.5 µg/L).

CONCLUSIONS

Risk of death due to cannabis toxicity is negligible. However, cannabis can prove fatal in circumstances with risk of traumatic physical injury, or in individuals with cardiac pathophysiologies. These indirect harms need careful consideration and further study to better elucidate the role cannabis plays in drug-related mortality. Furthermore, the relevance of cannabinoid quantifications in determining cause of death in coronial investigations is limited.

Alcohol use in adolescence as a risk factor for overdose in the 1986 Northern Finland Birth Cohort Study

Background

Overdoses and poisonings are among the most common causes of death in young adults. Adolescent problem drinking has been associated with psychiatric morbidity in young adulthood as well as with elevated risk for suicide attempts. There is limited knowledge on adolescent alcohol use as a risk factor for alcohol and/or drug overdoses in later life.

Methods

Here, data from The Northern Finland Birth Cohort 1986 study with a follow-up from adolescence to early adulthood were used to assess the associations between adolescent alcohol use and subsequent alcohol or drug overdose. Three predictors were used: age of first intoxication, self-reported alcohol tolerance and frequency of alcohol intoxication in adolescence. ICD-10-coded overdose diagnoses were obtained from nationwide registers. Use of illicit drugs or misuse of medication, Youth Self Report total score, family structure and mother’s education in adolescence were used as covariates.

Results

In multivariate analyses, early age of first alcohol intoxication [hazard ratios (HR) 4.5, 95% confidence intervals (CI) 2.2–9.2, P < 0.001], high alcohol tolerance (HR 3.1, 95% CI 1.6–6.0, P = 0.001) and frequent alcohol intoxication (HR 1.9, 95% CI 1.0–3.4, P = 0.035) all associated with the risk of overdoses. Early age of first intoxication (HR 5.2, 95% CI 1.9–14.7, P = 0.002) and high alcohol tolerance (HR 4.4, 95% CI 1.7–11.5, P = 0.002) also associated with intentional overdoses.

Conclusions

Alcohol use in adolescence associated prospectively with increased risk of overdose in later life. Early age of first intoxication, high alcohol tolerance and frequent alcohol intoxication are all predictors of overdoses.

Predictors of no, low and frequent emergency department use for any medical reason among patients with cannabis-related disorders attending Quebec (Canada) addiction treatment centres

INTRODUCTION

Patients with substance-related disorders and mental disorders (MD) contribute substantially to emergency department (ED) overcrowding. Few studies have identified predictors of ED use integrating service use correlates, particularly among patients with cannabis-related disorders (CRD). This study compared predictors of low (1-2 visits/year) or frequent (3+ visits/year) ED use with no ED use for a cohort of 9836 patients with CRD registered at Quebec (Canada) addiction treatment centres in 2012-2013.

METHODS

This longitudinal study used multinomial logistic regression to evaluate clinical, sociodemographic and service use variables from various databases as predictors of the frequency of ED use for any medical reason in 2015-2016 among patients with CRD.

RESULTS

Compared to non-ED users with CRD, frequent ED users included more women, rural residents, patients with serious MD and chronic CRD, dropouts from programs in addiction treatment centres and with less continuity of physician care. Compared with non-users, low ED users had more common MD and there more workers than students.

DISCUSSION AND CONCLUSIONS

Multimorbidity, including MD, chronic physical illnesses and other substance-related disorders than CRD, predicted more ED use and explained frequent use of outpatient services and prior specialised acute care, as did being 12-29 years, after controlling for all other covariates. Better continuity of physician care and reinforcement of programs like assertive community or integrated treatment, and chronic primary care models may protect against frequent ED use. Strategies like screening, brief intervention and treatment referral, including motivational therapy for preventing treatment dropout may also be expanded to decrease ED use.

Prevalences of and characteristics associated with single- and polydrug-involved U.S. Emergency Department Visits in 2018

INTRODUCTION

Nonfatal and fatal drug overdoses have recently increased. There are limited data describing the range of illicit, prescribed, and over-the-counter drugs involved in overdoses presenting to U.S. emergency departments (EDs).

METHODS

Using 2018 Healthcare Cost and Utilization Project (HCUP) Nationwide ED Sample (NEDS) data, we calculated weighted counts and percentages by drug among overdose-related ED visits. Overdose-related ED visits were those having an International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) drug poisoning code falling under parent codes T36-T50 (codes involving alcohol were not explicitly queried). We identified the top 30 mutually exclusive polydrug combinations and compared characteristics of visits by polydrug status.

RESULTS

In 2018, 908,234 ED visits had a T36-T50 drug poisoning code. The most frequently reported drugs involved were opioids (30.3% of visits; heroin: 15.2%), benzodiazepines (11.0%), stimulants (7.9%), other/unspecified antidepressants (7.1%), 4-aminophenol derivatives (6.6%), and other/unspecified drugs, medicaments, and biological substances (11.8%). Overdose was uncommon for most other drug classes (e.g., antibiotics). Polydrug visits were more likely to involve females (prevalence ratio [PR]: 1.14, 95% confidence interval [CI]: 1.12-1.16), be coded intentional self-harm (PR: 1.81, 95% CI: 1.77-1.85), and result in hospitalization (PR: 1.84, 95% CI: 1.79-1.89) or death (PR: 1.37, 95% CI: 1.22-1.53) compared to single-drug overdose-related visits. Benzodiazepines, opioids, and/or stimulants were most frequently involved in polydrug overdoses.

CONCLUSION

Opioids, benzodiazepines, and stimulants were most commonly reported in both single-drug and polydrug overdose-involved ED visits. Other drugs involved in overdoses included antidepressants and 4-aminophenol derivatives. Jurisdictions can use data on drugs involved in overdoses to better tailor prevention strategies to emerging needs.

Can you be a follower even when you do not follow the leader? Yes, you can

In the ongoing debate in the area of critical leadership studies, the nature of leader–follower relationships is a thorny issue. The nature of followership has been questioned, especially whether followers can display resistance behaviours while maintaining their follower position. Addressing this issue requires a dialectical approach in which followers and leaders alike are primary elements in leadership co-production. Followers who face destructive leaders are of special interest when leadership is studied as a co-creational process. This context favours the emergence of a full range of behavioural profiles in which passives and colluders will illustrate the destructive leadership co-production process, and those who resist demonstrate that followers may not follow the leader and still keep a followership purpose. A two-step data analysis procedure was conducted based on the behaviour descriptions of 123 followers having a destructive leader. A qualitative analysis (i.e. content analysis) showed a set of behaviours and their antecedents that suggest three main groups of followers: resisters, obedient and mixed behaviour. Treating these data quantitatively (i.e. latent class analysis), six followers’ profiles emerged: active resistance, passive resistance, passive obedience, conflict avoidance, support and mixed. Our findings provide evidence that followers who resist may do it for the sake of the organisation. We discuss our findings in light of followership theory, whereby joining role-based and constructionist approaches allows us to argue that followers may still be followers even when they do not invariably follow their leader.

The conundrum of polysubstance overdose

WHAT IS KNOWN AND OBJECTIVE

Treating an opioid overdose using an opioid receptor antagonist (such as naloxone) makes mechanistic sense and can be effective. Unfortunately, the majority of current drug overdose deaths involve polysubstance use (i.e., an opioid plus a non-opioid).

COMMENT

Respiratory depression induced by opioids results from excessive opioid molecules binding to opioid receptors. This effect can be reversed by an opioid receptor antagonist. However, the respiratory depression induced by non-opioid drugs is not due to action at opioid receptors; thus, an opioid receptor antagonist is ineffective in many of these cases. For respiratory depression induced by non-opioids, receptor antagonists are either not available (e.g., for propofol overdose) or there may be attendant risks with their use (e.g., seizures with flumazenil). This gives rise to a need for more effective ways to treat polysubstance overdose.

WHAT IS NEW AND CONCLUSION

A new approach to treating opioid-induced respiratory depression due to drug overdose focuses on agents that stimulate respiratory drive rather than competing for opioid receptors. Such an approach is "agnostic" to the cause of the respiratory depression, so might be a potential way to treat polysubstance overdose.

Patterns of substance use before and after hospitalization among patients seen by an inpatient addiction consult service: A latent transition analysis

BACKGROUND AND AIMS

Polysubstance use is common and contributes to morbidity and mortality of hospitalized patients, and yet little is known about patterns of substance use among hospitalized patients, or how an addiction consult service (ACS) might impact polysubstance use after discharge. The objective of this study was to identify patterns of substance use at admission and after discharge among hospitalized patients with substance use disorders who saw an ACS.

DESIGN

Prospective cohort study. We used latent transition analysis of substance use scores at the time of hospital admission and 30 to 90 days posthospitalization.

SETTING

Single, academic health center with an ACS in Portland, Oregon, from 2015 to 2018.

PARTICIPANTS/CASES

Patients were eligible if they received a consult to the inpatient ACS.

MEASUREMENTS

We used Addiction Severity Index-Lite scores to capture self-reported substance use at baseline and follow-up for heroin, other opioid, alcohol, amphetamine, and cocaine.

FINDINGS

From 2015 to 2018, 486 individuals consented to participate. More than half of patients used more than one substance at baseline. Of those reporting any baseline opioid use, nearly three-quarters (n=187, 69.5%) had polysubstance use in the previous 30 days, including alcohol (n=80, 29.7%), cocaine (n=25, 9.3%), or amphetamine use (n=142, 52.8%). We identified three patterns of substance use at baseline: 1) alcohol use dominant, 2) polysubstance use dominant, and 3) heroin and other opioid use dominant. Patients transitioned along five trajectories to three different follow-up profiles that showed lower endorsement of all substances used. Slightly more than 40% (40.1%) of patients newly endorsed abstinence of at least one substance at follow-up.

CONCLUSIONS

Polysubstance use is common in hospitalized patients with substance use disorders and identifying patterns of polysubstance use can guide clinical management. Hospital providers should prepare to manage polysubstance use during hospitalization and hospitals should broaden care beyond interventions for opioid use disorder.

Two latent classes of diagnostic and treatment procedures among traumatic brain injury inpatients

To characterize latent classes of diagnostic and/or treatment procedures among hospitalized U.S. adults, 18-64 years, with primary diagnosis of TBI from 2004-2014 Nationwide Inpatient Samples, latent class analysis (LCA) was applied to 10 procedure groups and differences between latent classes on injury, patient, hospital and healthcare utilization outcome characteristics were modeled using multivariable regression. Using 266,586 eligible records, LCA resulted in two classes of hospitalizations, namely, class I (n = 217,988) (mostly non-surgical) and class II (n = 48,598) (mostly surgical). Whereas orthopedic procedures were equally likely among latent classes, skin-related, physical medicine and rehabilitation procedures as well as behavioral health procedures were more likely among class I, and other types of procedures were more likely among class II. Class II patients were more likely to have moderate-to-severe TBI, to be admitted on weekends, to urban, medium-to-large hospitals in Midwestern, Southern or Western regions, and less likely to be > 30 years, female or non-White. Class II patients were also less likely to be discharged home and necessitated longer hospital stays and greater hospitalization charges. Surgery appears to distinguish two classes of hospitalized patients with TBI with divergent healthcare needs, informing the planning of healthcare services in this target population.

One Is Not Enough: Understanding and Modeling Polysubstance Use

Substance use disorder (SUD) is a chronic, relapsing disease with a highly multifaceted pathology that includes (but is not limited to) sensitivity to drug-associated cues, negative affect, and motivation to maintain drug consumption. SUDs are highly prevalent, with 35 million people meeting criteria for SUD. While drug use and addiction are highly studied, most investigations of SUDs examine drug use in isolation, rather than in the more prevalent context of comorbid substance histories. Indeed, 11.3% of individuals diagnosed with a SUD have concurrent alcohol and illicit drug use disorders. Furthermore, having a SUD with one substance increases susceptibility to developing dependence on additional substances. For example, the increased risk of developing heroin dependence is twofold for alcohol misusers, threefold for cannabis users, 15-fold for cocaine users, and 40-fold for prescription misusers. Given the prevalence and risk associated with polysubstance use and current public health crises, examining these disorders through the lens of co-use is essential for translatability and improved treatment efficacy. The escalating economic and social costs and continued rise in drug use has spurred interest in developing preclinical models that effectively model this phenomenon. Here, we review the current state of the field in understanding the behavioral and neural circuitry in the context of co-use with common pairings of alcohol, nicotine, cannabis, and other addictive substances. Moreover, we outline key considerations when developing polysubstance models, including challenges to developing preclinical models to provide insights and improve treatment outcomes.