Hepatitis C in Black Individuals in the US: A Review.

Importance: In the US, the prevalence of hepatitis C virus (HCV) is 1.8% among people who are Black and 0.8% among people who are not Black. Mortality rates due to HCV are 5.01/100 000 among people who are Black and 2.98/100 000 among people who are White. Observations: While people of all races and ethnicities experienced increased rates of incident HCV between 2015 and 2021, Black individuals experienced the largest percentage increase of 0.3 to 1.4/100 000 (367%) compared with 1.8 to 2.7/100 000 among American Indian/Alaska Native (50%), 0.3 to 0.9/100 000 among Hispanic (200%), and 0.9 to 1.6/100 000 among White (78%) populations. Among 47 687 persons diagnosed with HCV in 2019-2020, including 37 877 (79%) covered by Medicaid (7666 Black and 24 374 White individuals), 23.5% of Black people and 23.7% of White people with Medicaid insurance initiated HCV treatment. Strategies to increase HCV screening include electronic health record prompts for universal HCV screening, which increased screening tests from 2052/month to 4169/month in an outpatient setting. Awareness of HCV status can be increased through point-of-care testing in community-based settings, which was associated with increased likelihood of receiving HCV test results compared with referral for testing off-site (69% on-site vs 19% off-site, P < .001). Access to HCV care can be facilitated by patient navigation, in which an individual is assigned to work with a patient to help them access care and treatments; this was associated with greater likelihood of HCV care access (odds ratio, 3.7 [95% CI, 2.9-4.8]) and treatment initiation within 6 months (odds ratio, 3.2 [95% CI, 2.3-4.2]) in a public health system providing health care to individuals regardless of their insurance status or ability to pay compared with usual care. Eliminating Medicaid's HCV treatment restrictions, including removal of a requirement for advanced fibrosis or a specialist prescriber, was associated with increased treatment rates from 2.4 persons per month to 72.3 persons per month in a retrospective study of 10 336 adults with HCV with no significant difference by race (526/1388 [37.8%] for Black vs 2706/8277 [32.6%] for White patients; adjusted odds ratio, 1.02 [95% CI, 0.8-1.3]). Conclusions and Relevance: In the US, the prevalence of HCV is higher in people who are Black than in people who are not Black. Point-of-care HCV tests, patient navigation, electronic health record prompts, and unrestricted access to HCV treatment in community-based settings have potential to increase diagnosis and treatment of HCV and improve outcomes in people who are Black.

Synthesis of the Prototypical Cyclopropyl Dipeptide Mimic and Evaluation of Its Turn-Inducing Capability.

The (+) and (-) enantiomers of a new turn-inducing cyclopropyl dipeptide mimic have been synthesized and evaluated. The mimic derives its turn-inducing capabilities solely from the cyclopropyl group and without the conformational biasing that would be provided by side-chain substituents. The mimic and peptide-mimic hybrids prepared from it have been studied using a combination of spectroscopic techniques (NMR, IR, and CD). The dipeptide mimic itself displays intramolecular hydrogen bonding in organic solvents, which differs from that observed in natural peptide turns. In contrast, more elaborate peptide-mimic hybrids exhibit hydrogen bonding characteristics that vary with solvent but are consistent with structures found in the tetrapeptide portion (i → i + 3) of a native ß-turn.

A Latent Class Analysis of HIV Risk Factors Among Men and Women with Opioid Use Disorder in Pre-trial Detention.

Adults entering pre-trial detention who inject drugs are at high risk for acquiring HIV/AIDS. In the current study, we examined pre-incarceration HIV risk behaviors among 114 people with opioid use disorder who inject drugs. Participants were recruited from the Baltimore City Detention Center as part of a randomized controlled trial of pre-release methadone treatment. Using latent class analysis, we found three separate latent classes, which we identified as the sex exchange class (14.2%), drug equipment sharing class (36.8%) and lower risk class (49.0%). Women in the sex exchange class (n = 16) reported having multiple male partners and selling sex for money or drugs; however, this group also reported more consistent condom use and less frequent injection drug and equipment sharing than participants in the drug equipment sharing class. Our findings highlight distinct profiles of jail detainees with OUD based on their risks for HIV, and could inform more targeted interventions for each group.Clinical Trials Registration: Clinicaltrials.gov NCT02334215.

Tunable Supramolecular Gel Properties by Varying Thermal History.

The possibility of using differential pre-heating prior to supramolecular gelation to control the balance between hydrogen-bonding and aromatic stacking interactions in supramolecular gels and obtain consequent systematic regulation of structure and properties is demonstrated. Using a model aromatic peptide amphiphile, Fmoc-tyrosyl-leucine (Fmoc-YL) and a combination of fluorescence, infrared, circular dichroism and NMR spectroscopy, it is shown that the balance of these interactions can be adjusted by temporary exposure to elevated temperatures in the range 313-365 K, followed by supramolecular locking in the gel state by cooling to room temperature. Distinct regimes can be identified regarding the balance between H-bonding and aromatic stacking interactions, with a transition point at 333 K. Consequently, gels can be obtained with customizable properties, including supramolecular chirality and gel stiffness. The differential supramolecular structures also result in changes in proteolytic stability, highlighting the possibility of obtaining a range of supramolecular architectures from a single molecular structure by simply controlling the pre-assembly temperature.

LC-HRMS-Database Screening Metrics for Rapid Prioritization of Samples to Accelerate the Discovery of Structurally New Natural Products.

In order to accelerate the isolation and characterization of structurally new or novel secondary metabolites, it is crucial to develop efficient strategies that prioritize samples with greatest promise early in the workflow so that resources can be utilized in a more efficient and cost-effective manner. We have developed a metrics-based prioritization approach using exact LC-HRMS, which uses data for 24 618 marine natural products held in the PharmaSea database. Each sample was evaluated and allocated a metric score by a software algorithm based on the ratio of new masses over the total (sample novelty), ratio of known masses over the total (chemical novelty), number of peaks above a defined peak area threshold (sample complexity), and peak area (sample diversity). Samples were then ranked and prioritized based on these metric scores. To validate the approach, eight marine sponges and six tunicate samples collected from the Fiji Islands were analyzed, metric scores calculated, and samples targeted for isolation and characterization of new compounds. Structures of new compounds were elucidated by spectroscopic techniques, including 1D and 2D NMR, MS, and MS/MS. Structures were confirmed by computer-assisted structure elucidation methods (CASE) using the ACD/Structure Elucidator Suite.

Functional characterization of a constitutively active kinase variant of Arabidopsis phototropin 1.

Phototropins (phots) are plasma membrane-associated serine/threonine kinases that coordinate a range of processes linked to optimizing photosynthetic efficiency in plants. These photoreceptors contain two light-, oxygen-, or voltage-sensing (LOV) domains within their N terminus, with each binding one molecule of flavin mononucleotide as a UV/blue light-absorbing chromophore. Although phots contain two LOV domains, light-induced activation of the C-terminal kinase domain and subsequent receptor autophosphorylation is controlled primarily by the A'α-LOV2-Jα photosensory module. Mutations that disrupt interactions between the LOV2 core and its flanking helical segments can uncouple this mode of light regulation. However, the impact of these mutations on phot function in Arabidopsis has not been explored. Here we report that histidine substitution of Arg-472 located within the A'α-helix of Arabidopsis phot1 constitutively activates phot1 kinase activity in vitro without affecting LOV2 photochemistry. Expression analysis of phot1 R472H in the phot-deficient mutant confirmed that it is autophosphorylated in darkness in vivo but unable to initiate phot1 signaling in the absence of light. Instead, we found that phot1 R472H is poorly functional under low-light conditions but can restore phototropism, chloroplast accumulation, stomatal opening, and leaf positioning and expansion at higher light intensities. Our findings suggest that Arabidopsis can adapt to the elevated phosphorylation status of the phot1 R472H mutant in part by reducing its stability, whereas the activity of the mutant under high-light conditions can be attributed to additional increases in LOV2-mediated photoreceptor autophosphorylation.

Characterisation of a pucBA deletion mutant from Rhodopseudomonas palustris lacking all but the pucBAd genes.

Rhodopseudomonas palustris is a species of purple photosynthetic bacteria that has a multigene family of puc genes that encode the alpha and beta apoproteins, which form the LH2 complexes. A genetic dissection strategy has been adopted in order to try and understand which spectroscopic form of LH2 these different genes produce. This paper presents a characterisation of one of the deletion mutants generated in this program, the pucBAd only mutant. This mutant produces an unusual spectroscopic form of LH2 that only has a single large NIR absorption band at 800 nm. Spectroscopic and pigment analyses on this complex suggest that it has basically a similar overall structure as that of the wild-type HL LH2 complex. The mutant has the unique phenotype where the mutant LH2 complex is only produced when cells are grown at LL. At HL the mutant only produces the LH1-RC core complex.

Pharmacotherapy for opioid addiction in community corrections.

Pharmacotherapy for opioid addiction with methadone, buprenorphine, and naltrexone has proven efficacy in reducing illicit opioid use. These treatments are under-utilized among opioid-addicted individuals on parole, probation, or in drug courts. This paper examines the peer-reviewed literature on the effectiveness of pharmacotherapy for opioid addiction of adults under community-based criminal justice supervision in the US. Compared to general populations, there are relatively few papers addressing the separate impact of pharmacotherapy on individuals under community supervision. Tentative conclusions can be drawn from the extant literature. Reasonable evidence exists that illicit opioid use and self-reported criminal behaviour decline after treatment entry, and that these outcomes are as favourable among individuals under criminal justice supervision as the general treatment population. Surprisingly, there is no conclusive evidence regarding the extent to which pharmacotherapy impacts the likelihood of arrest and incarceration among individuals under supervision. However, given the proven efficacy of these three medications in reducing illicit opioid use and the evidence that, in the general population, methadone and buprenorphine treatment are associated with reduction in overdose mortality, the use of all three pharmacotherapies among patients under criminal justice supervision should be expanded while more data are collected on their impact on arrest and incarceration.

Manipulating adenovirus hexon hypervariable loops dictates immune neutralisation and coagulation factor X-dependent cell interaction in vitro and in vivo.

Adenoviruses are common pathogens, mostly targeting ocular, gastrointestinal and respiratory cells, but in some cases infection disseminates, presenting in severe clinical outcomes. Upon dissemination and contact with blood, coagulation factor X (FX) interacts directly with the adenovirus type 5 (Ad5) hexon. FX can act as a bridge to bind heparan sulphate proteoglycans, leading to substantial Ad5 hepatocyte uptake. FX "coating" also protects the virus from host IgM and complement-mediated neutralisation. However, the contribution of FX in determining Ad liver transduction whilst simultaneously shielding the virus from immune attack remains unclear. In this study, we demonstrate that the FX protection mechanism is not conserved amongst Ad types, and identify the hexon hypervariable regions (HVR) of Ad5 as the capsid proteins targeted by this host defense pathway. Using genetic and pharmacological approaches, we manipulate Ad5 HVR interactions to interrogate the interplay between viral cell transduction and immune neutralisation. We show that FX and inhibitory serum components can co-compete and virus neutralisation is influenced by both the location and extent of modifications to the Ad5 HVRs. We engineered Ad5-derived HVRs into the rare, native non FX-binding Ad26 to create Ad26.HVR5C. This enabled the virus to interact with FX at high affinity, as quantified by surface plasmon resonance, FX-mediated cell binding and transduction assays. Concomitantly, Ad26.HVR5C was also sensitised to immune attack in the absence of FX, a direct consequence of the engineered HVRs from Ad5. In both immune competent and deficient animals, Ad26.HVR5C hepatic gene transfer was mediated by FX following intravenous delivery. This study gives mechanistic insight into the pivotal role of the Ad5 HVRs in conferring sensitivity to virus neutralisation by IgM and classical complement-mediated attack. Furthermore, through this gain-of-function approach we demonstrate the dual functionality of FX in protecting Ad26.HVR5C against innate immune factors whilst determining liver targeting.

Update on Barriers to Pharmacotherapy for Opioid Use Disorders.

PURPOSE OF REVIEW: The recent heroin and prescription opioid misuse epidemic has led to a sharp increase in the number of opioid overdose deaths in the USA. Notwithstanding the availability of three FDA-approved medications (methadone, buprenorphine, and naltrexone) to treat opioid use disorder, these medications are underutilized. This paper provides an update from the recent peer-reviewed literature on barriers to the use of these medications. FINDINGS: These barriers are interrelated and can be categorized as financial, regulatory, geographic, attitudinal, and logistic. While financial barriers are common to all three medications, other barriers are medication-specific. The adverse impact of the current opioid epidemic on public health can be reduced by increasing access to effective pharmacotherapy for opioid use disorder.

The concurrent validity of the Problem Oriented Screening Instrument for Teenagers (POSIT) substance use/abuse subscale in adolescent patients in an urban federally qualified health center.

BACKGROUND: The Problem Oriented Screening Instrument for Teenagers (POSIT) substance use/abuse subscale has been validated with high school students, adolescents with criminal justice involvement, and adolescent substance use treatment samples using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R and DSM-IV. This study examines the concurrent validity of the POSIT's standard 17-item substance use/abuse subscale and a revised, shorter 11-item version using DSM-5 substance use disorder diagnoses. METHODS: Adolescents (N = 525; 93% African American, 55% female) 12-17 years of age awaiting primary care appointments at a Federally Qualified Health Center in Baltimore, Maryland completed the 17-item POSIT substance use/abuse subscale and items from a modified World Mental Health Composite International Diagnostic Interview corresponding to DSM-5 alcohol use disorder (AUD) and cannabis use disorder (CUD). Receiver operating characteristic curves, sensitivities, and specificities were examined with DSM-5 AUD, CUD, and a diagnosis of either or both disorders for the standard and revised subscales using risk cutoffs of either 1 or 2 POSIT "yes" responses. RESULTS: For the 17-item subscale, sensitivities were generally high using either cutoff (range: 0.79-1.00), although a cutoff of 1 was superior (sensitivities were 1.00 for AUD, CUD, and for either disorder). Specificities were also high using either cutoff (range: 0.81-0.95) but were higher using a cutoff of 2. For the 11-item subscale, a cutoff of 1 yielded higher sensitivities than a cutoff of 2 (ranges for 1 and 2: 0.96-1.00 and 0.79-0.86, respectively). Specificities for this subscale were higher using a cutoff of 2 (ranges for 1 and 2: 0.82-0.89 and 0.89-0.96, respectively). CONCLUSIONS: Findings suggest that the POSIT's substance use/abuse subscale is a potentially useful tool for screening adolescents in primary care for AUD or CUD using a cutoff of 1 or 2. The briefer, revised subscale may be preferable to the standard subscale in busy pediatric practices.

Spontaneous Assembly of an Organic-Inorganic Nucleic Acid Z-DNA Double-Helix Structure.

Herein, we report a hybrid polyoxometalate organic-inorganic compound, Na2 [(HGMP)2 Mo5 O15 ]⋅7 H2 O (1; where GMP=guanosine monophosphate), which spontaneously assembles into a structure with dimensions that are strikingly similar to those of the naturally occurring left-handed Z-form of DNA. The helical parameters in the crystal structure of the new compound, such as rise per turn and helical twist per dimer, are nearly identical to this DNA conformation, allowing a close comparison of the two structures. Solution circular dichroism studies show that compound 1 also forms extended secondary structures in solution. Gel electrophoresis studies demonstrate the formation of non-covalent adducts with natural plasmids. Thus we show a route by which simple hybrid inorganic-organic monomers, such as compound 1, can spontaneously assemble into a double helix without the need for a covalently connected linear sequence of nucleic acid base pairs.

Multifaceted Studies of the DNA Interactions and In Vitro Cytotoxicity of Anticancer Polyaromatic Platinum(II) Complexes.

This study reports a detailed biophysical analysis of the DNA binding and cytotoxicity of six platinum complexes (PCs). They are of the type [Pt(PL )(SS-dach)]Cl2 , where PL is a polyaromatic ligand and SS-dach is 1S,2S-diaminocyclohexane. The DNA binding of these complexes was investigated using six techniques including ultraviolet and fluorescence spectroscopy, linear dichroism, synchrotron radiation circular dichroism, isothermal titration calorimetry and mass spectrometry. This portfolio of techniques has not been extensively used to study the interactions of such complexes previously; each assay provided unique insight. The in vitro cytotoxicity of these compounds was studied in ten cell lines and compared to the effects of their R,R enantiomers; activity was very high in Du145 and SJ-G2 cells, with some submicromolar IC50 values. In terms of both DNA affinity and cytotoxicity, complexes of 5,6-dimethyl-1,10-phenanthroline and 2,2'-bipyridine exhibited the greatest and least activity, respectively, suggesting that there is some correlation between DNA binding and cytotoxicity.

Structure of the atypical bacteriocin pectocin M2 implies a novel mechanism of protein uptake.

The colicin-like bacteriocins are potent protein antibiotics that have evolved to efficiently cross the outer membrane of Gram-negative bacteria by parasitizing nutrient uptake systems. We have structurally characterized the colicin M-like bacteriocin, pectocin M2, which is active against strains of Pectobacterium spp. This unusual bacteriocin lacks the intrinsically unstructured translocation domain that usually mediates translocation of these bacteriocins across the outer membrane, containing only a single globular ferredoxin domain connected to its cytotoxic domain by a flexible α-helix, which allows it to adopt two distinct conformations in solution. The ferredoxin domain of pectocin M2 is homologous to plant ferredoxins and allows pectocin M2 to parasitize a system utilized by Pectobacterium to obtain iron during infection of plants. Furthermore, we identify a novel ferredoxin-containing bacteriocin pectocin P, which possesses a cytotoxic domain homologous to lysozyme, illustrating that the ferredoxin domain acts as a generic delivery module for cytotoxic domains in Pectobacterium.

A single-component multidrug transporter of the major facilitator superfamily is part of a network that protects Escherichia coli from bile salt stress.

Resistance to high concentrations of bile salts in the human intestinal tract is vital for the survival of enteric bacteria such as Escherichia coli. Although the tripartite AcrAB-TolC efflux system plays a significant role in this resistance, it is purported that other efflux pumps must also be involved. We provide evidence from a comprehensive suite of experiments performed at two different pH values (7.2 and 6.0) that reflect pH conditions that E. coli may encounter in human gut that MdtM, a single-component multidrug resistance transporter of the major facilitator superfamily, functions in bile salt resistance in E. coli by catalysing secondary active transport of bile salts out of the cell cytoplasm. Furthermore, assays performed on a chromosomal ΔacrB mutant transformed with multicopy plasmid encoding MdtM suggested a functional synergism between the single-component MdtM transporter and the tripartite AcrAB-TolC system that results in a multiplicative effect on resistance. Substrate binding experiments performed on purified MdtM demonstrated that the transporter binds to cholate and deoxycholate with micromolar affinity, and transport assays performed on inverted vesicles confirmed the capacity of MdtM to catalyse electrogenic bile salt/H(+) antiport.

Discovery of a Single Monooxygenase that Catalyzes Carbamate Formation and Ring Contraction in the Biosynthesis of the Legonmycins.

Pyrrolizidine alkaloids (PAs) are a group of natural products with important biological activities. The discovery and characterization of the multifunctional FAD-dependent enzyme LgnC is now described. The enzyme is shown to convert indolizidine intermediates into pyrrolizidines through an unusual ring expansion/contraction mechanism, and catalyze the biosynthesis of new bacterial PAs, the so-called legonmycins. By genome-driven analysis, heterologous expression, and gene inactivation, the legonmycins were also shown to originate from non-ribosomal peptide synthetases (NRPSs). The biosynthetic origin of bacterial PAs has thus been disclosed for the first time.

The CRAFFT cut-points and DSM-5 criteria for alcohol and other drugs: a reevaluation and reexamination.

BACKGROUND: The CRAFFT, previously validated against DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) diagnostic criteria, is the most widely used screening instrument for alcohol and other substance misuse in adolescents. The present secondary analysis study sought to compare the CRAFFT with the new DSM-5 diagnostic criteria in order to assess the CRAFFT's psychometric properties and determine the optimal cut-point for identifying adolescents in need of further assessment. METHODS: Participants were primary care patients aged 12-17 (N = 525) who were recruited while waiting for a medical appointment in an urban federally qualified health center in Baltimore, Maryland, USA. Participants were administered the CRAFFT and the Composite International Diagnostic Interview, second edition, modified to include the new DSM-5 craving item. The authors examined the performance of the CRAFFT in identifying any problem use (defined as 1 or more DSM-5 criteria) and any DSM-5 substance use disorder (2 or more DSM-5 criteria) for alcohol or drugs other than tobacco. The authors examined sensitivity, specificity, and receiver operating characteristic areas under the curve (AUC) to determine the optimal CRAFFT cut-point(s) for predicting any problem use and any DSM-5 substance use disorder (SUD). RESULTS: Examining the CRAFFT as a continuous measure, AUC values were 0.93 for problem use or higher and 0.97 for DSM-5 SUD. Consistent with previously recommended cut-points for the CRAFFT, the cut-point of 2 performed optimally for identifying adolescents both exhibiting problem use of alcohol or drugs and meeting DSM-5 SUD criteria for alcohol or other drugs. CONCLUSIONS: Despite changes in the DSM substance use diagnostic criteria, the CRAFFT continues to demonstrate excellent sensitivity and specificity at its established cut-point of 2. Additional studies examining the CRAFFT in light of the new DSM-5 diagnostic criteria with more diverse populations are warranted.

Treatment Outcomes of African American Buprenorphine Patients by Parole and Probation Status.

This secondary analysis compared outcomes of African-American adults newly-admitted to buprenorphine treatment who were on parole and probation to patients who were not under criminal justice supervision. Buprenorphine patients (N=300) were randomly assigned to receive either Intensive Outpatient Treatment (IOP) or Standard Outpatient Treatment (OP) treatment and were assessed at baseline, 3- and 6-months. There were no differences between groups in treatment retention. Among probationers/parolees, IOP was associated with lower 3-month treatment retention compared to OP, but among participants not on probation/parole the relationship was reversed (p=.004). Both conditions showed significant declines in heroin and cocaine use, illegal activity, and in meeting DSM-IV criteria for opioid and cocaine dependence. Probationers/parolees reported lower frequency of illegal activities at 3-months compared to non-probationers/parolees (p=.007). Buprenorphine treatment should be made more widely available to individuals on parole/probation as they respond as well to treatment as patients not supervised by the criminal justice system.

Structure of biomimetic casein micelles: Critical tests of the hydrophobic colloid and multivalent-binding models using recombinant deuterated and phosphorylated ß-casein.

Milk contains high concentrations of amyloidogenic casein proteins and is supersaturated with respect to crystalline calcium phosphates such as apatite. Nevertheless, the mammary gland normally remains unmineralized and free of amyloid. Unlike κ-casein, ß- and αS-caseins are highly effective mineral chaperones that prevent ectopic and pathological calcification of the mammary gland. Milk invariably contains a mixture of two to five different caseins that act on each other as molecular chaperones. Instead of forming amyloid fibrils, several thousand caseins and hundreds of nanoclusters of amorphous calcium phosphate combine to form fuzzy complexes called casein micelles. To understand the biological functions of the casein micelle its structure needs to be understood better than at present. The location in micelles of the highly amyloidogenic κ-casein is disputed. In traditional hydrophobic colloid models, it, alone, forms a stabilizing surface coat that also determines the average size of the micelles. In the recent multivalent-binding model, κ-casein is present throughout the micelle, in intimate contact with the other caseins. To discriminate between these models, a range of biomimetic micelles was prepared using a fixed concentration of the mineral chaperone ß-casein and nanoclusters of calcium phosphate, with variable concentrations of κ-casein. A biomimetic micelle was also prepared using a highly deuterated and in vivo phosphorylated recombinant ß-casein with calcium phosphate and unlabelled κ-casein. Neutron and X-ray scattering experiments revealed that κ-casein is distributed throughout the micelle, in quantitative agreement with the multivalent-binding model but contrary to the hydrophobic colloid models.

Hospital admissions among patients with Comorbid Substance Use disorders: a secondary analysis of predictors from the NavSTAR Trial.

BACKGROUND: Individuals with substance use disorders (SUDs) frequently use acute hospital services. The Navigation Services to Avoid Rehospitalization (NavSTAR) trial found that a patient navigation intervention for hospitalized patients with comorbid SUDs reduced subsequent inpatient admissions compared to treatment-as-usual (TAU). METHODS: This secondary analysis extends previous findings from the NavSTAR trial by examining whether selected patient characteristics independently predicted hospital service utilization and moderated the effect of the NavSTAR intervention. Participants were 400 medical/surgical hospital patients with comorbid SUDs. We analyzed 30- and 90-day inpatient readmissions (one or more readmissions) and cumulative incidence of inpatient admissions through 12 months using multivariable logistic and negative binomial regression, respectively. RESULTS: Consistent with primary findings and controlling for patient factors, NavSTAR participants were less likely than TAU participants to be readmitted within 30 (P = 0.001) and 90 (P = 0.03) days and had fewer total readmissions over 12 months (P = 0.008). Hospitalization in the previous year (P < 0.001) was associated with cumulative readmissions over 12 months, whereas Medicaid insurance (P = 0.03) and index diagnoses of infection (P = 0.001) and injuries, poisonings, or procedural complications (P = 0.004) were associated with fewer readmissions. None of the selected covariates moderated the effect of the NavSTAR intervention. CONCLUSIONS: Previous findings showed that patient navigation could reduce repeat hospital admissions among patients with comorbid SUDs. Several patient factors were independently associated with readmission. Future research should investigate risk factors for hospital readmission among patients with comorbid SUDs to optimize interventions. TRIAL REGISTRATION: NIH ClinicalTrials.gov NCT02599818, Registered November 9, 2015 https://classic. CLINICALTRIALS: gov/ct2/show/NCT02599818 .