Contents lists available at ScienceDirect Drug and Alcohol Dependence journal homepage: www.elsevier.com/locate/drugalcdep Opioid-related hospitalizations in Pennsylvania: A latent class analysis Stephen J. Liu a, ⁎ , Christina Mair a ,ThomasJ.Songer a ,ElizabethE.Krans b,c ,AbdusWahed a , Evelyn Talbott a a University of Pittsburgh, Graduate School of Public Health, 130 DeSoto St, Pittsburgh, 15261 PA, USA b University of Pittsburgh, Department of Obstetrics, Gynecology and Reproductive Sciences, 300 Halket Street, Pittsburgh, 15213 PA, USA c Magee-Womens Research Institute, 204 Craft Avenue, Pittsburgh, 15213 PA, USA ARTICLEINFO Keywords: Opioid use disorder Opioid overdose Latent class analysis Polysubstance use ABSTRACT Background: Opioid abuse is associated with substantial morbidity and often results in hospitalization. Despite this, patient-level factors associated with opioid-related hospitalizations are not well understood. Methods: We used the Pennsylvania Health Care Cost Containment Council dataset (2000–2014) to identify opioid-related hospitalizations using primary and/or secondary ICD-9-CM hospital discharge codes for opioid usedisorder(OUD),opioidpoisoning,andheroinpoisoning.Latentclassanalyses(LCA)ofpatient-levelfactors including sociodemographic characteristics, pregnancy, alcohol, tobacco, other substance use, and psychiatric disorders were used to identify common patterns within hospitalizations. Results: Among28,538,499hospitalizations,430,569(1.5%)wereopioid-related.LCAidentifiedfivelatentclass (LC) patient groups associated with opioid-related hospitalizations: pregnant women with OUD (LC1); women over 65 with opioid overdose (LC2); OUD, polysubstance use and co-occurring psychiatric disorders (LC3); patientswithopioidoverdosewithoutco-occurringpolysubstanceuse(LC4);andAfricanAmericanpatientswith OUDandco-occurringcocaineuse(LC5).LC3wasthelargestlatentclass(58.2%)withannualhospitalizations doubling over time. Discussion: Amongpatientswithopioid-relateddischarges,weidentifiedfivesubpopulationsamongthissample. ThesefindingssuggestincreasedoutpatientOUDtreatment,mentalhealthservicesupportforpatientswithco- occurring psychiatric disorders and polysubstance use to prevent overdose and hospitalization. 1. Introduction The prevalence of opioid use disorder (OUD) has reached epidemic proportions in the United States (Han et al., 2015; Substance Abuse and Mental Health Services Administration, 2016). In 2017, an estimated 11.4 million Americans misused opioids in the past year, including prescription opioids and heroin (Substance Abuse and Mental Health Services Administration, 2017). Due to rising rates of morbidity and mortality as- sociated with opioid abuse, opioid-related hospitalizations in the United States (US) have increased substantially. Between 2001 and 2012, over 600,000 prescription opioid and heroin overdose-associated hospital ad- missions occurred across the US with an associated increase in annual hospitalization costs of more than $700 million (Hsuetal.,2017). Pennsylvaniahasthe3rdhighestdrugoverdosedeathrateintheUnited Statesandhasobservedanincreasingrateofopioid-relatedhospitalizations, especiallyinruralcomparedtourbancountiesfrom2000to2014(Centers for Disease Control and Prevention, National Vital Statistics System/ Mortality 2019; PA Health Care Cost Containment Council (PHC4), 2014). Pennsylvaniaranks9thinthenationinprescribingrateoflong-actingpain relievers and above the median for prescription of opioid pain relievers (OPR)andhighdoseOPR(Paulozzietal.,2014).Overall,therewere3500 opioid overdose-related hospitalizations recorded in 2017 due to pain medicationoverdoseorheroinoverdose(PAHealthCareCostContainment Council (PHC4), 2018). Evolving national patterns of opioid use are also reflectedinPennsylvania’soverdosedeathrates.Syntheticopioidsincluding fentanylarenowresponsiblefora65%increaseinPAdrugoverdosedeaths from 2015 to 2017 (Ciccarone, 2019; Drug Enforcement Agency Philadelphia division, University of Pittsburgh 2018). Despite high healthcare costs associated with opioid use, patient- levelfactorspredictiveofopioid-relatedhospitalizationsremainpoorly understood. Existing evaluations (Fulton-Kehoe et al., 2015; Mosher etal.,2014; Zedleretal.,2014)haveidentifiedseveralfactors–chronic opioid therapy, use of other drugs, COPD, depression, hypertension, opioid dependence, and psychiatric disorders– associated with an in- creased risk of opioid hospitalizations and overdoses. However, these studies utilized multiple logistic regression and other descriptive https://doi.org/10.1016/j.drugalcdep.2019.05.009 Received9January2019;Receivedinrevisedform2May2019;Accepted2May2019 ⁎ Corresponding author. E-mail address: STL45@pitt.edu (S.J. Liu). Drug and Alcohol Dependence 202 (2019) 185–190 Available online 19 July 2019 0376-8716/ © 2019 Published by Elsevier B.V. T