title: Association between trajectories of buprenorphine treatment and emergency department and in-patient utilization.
abstract: OBJECTIVE
  Uncertainty about optimal treatment duration for buprenorphine opioid agonist therapy may lead to substantial variation in provider and payer decision-making regarding treatment course. We aimed to identify distinct trajectories of buprenorphine use and examine outcomes associated with these trajectories to guide health system interventions regarding treatment length.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  US Pennsylvania Medicaid.
  
  
  METHODS
  A total of 10 945 enrollees aged 18-64 years initiating buprenorphine treatment between 2007 and 2012.
  
  
  METHODS
  Group-based trajectory models were used to identify trajectories based on monthly proportion of days covered with buprenorphine in the 12 months post-treatment initiation. We used separate multivariable Cox proportional hazard models to examine associations between trajectories and time to first all-cause hospitalization and emergency department (ED) visit within 12 months after the first-year treatment.
  
  
  RESULTS
  Six trajectories [Bayesian information criterion (BIC) = -86 246.70] were identified: 24.9% discontinued buprenorphine < 3 months, 18.7% discontinued between 3 and 5 months, 12.4% discontinued between 5 and 8 months, 13.3% discontinued > 8 months, 9.5% refilled intermittently and 21.2% refilled persistently for 12 months. Persistent refill trajectories were associated with an 18% lower risk of all-cause hospitalizations [hazard ratio (HR) = 0.82, 95% confidence interval (CI) = 0.70-0.95] and 14% lower risk of ED visits (HR = 0.86, 95% CI = 0.78-0.95) in the subsequent year, compared with those discontinuing between 3 and 5 months.
  
  
  CONCLUSIONS
  Six distinct buprenorphine treatment trajectories were identified in this population-based low-income Medicaid cohort in Pennsylvania, USA. There appears to be an association between persistent use of buprenorphine for 12 months and lower risk of all-cause hospitalizations/emergency department visits.
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ, USA.|Center for Pharmaceutical, Policy and Prescribing, Health Policy Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Wei-Hsuan
authors.initials: WH
authors.lastname: Lo-Ciganic
authors.affiliation: Center for Pharmaceutical, Policy and Prescribing, Health Policy Institute, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.|Center for Health Equity Research and Promotion, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, USA.
authors.forename: Walid F
authors.initials: WF
authors.lastname: Gellad
authors.affiliation: Center for Pharmaceutical, Policy and Prescribing, Health Policy Institute, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.|Center for Health Equity Research and Promotion, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Gordon
authors.affiliation: Center for Pharmaceutical, Policy and Prescribing, Health Policy Institute, University of Pittsburgh, Pittsburgh, PA, USA.|School of Social Work, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Gerald
authors.initials: G
authors.lastname: Cochran
authors.affiliation: Center for Pharmaceutical, Policy and Prescribing, Health Policy Institute, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Pharmaceutical Science, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Zemaitis
authors.affiliation: Pennsylvania Department of Human Services, Harrisburg, PA, USA.
authors.forename: Terri
authors.initials: T
authors.lastname: Cathers
authors.affiliation: Pennsylvania Department of Human Services, Harrisburg, PA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Kelley
authors.affiliation: Center for Pharmaceutical, Policy and Prescribing, Health Policy Institute, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Health Policy and Management, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Donohue
mesh_terms: D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D002047:Buprenorphine / Q000627:therapeutic use*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008484:Medicaid; D008875:Middle Aged; D009293:Opioid-Related Disorders / Q000534:rehabilitation*; D010414:Pennsylvania; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D002047:Buprenorphine
keywords: Buprenorphine; Medicaid; Opioid use disorders; group-based trajectory models; opioid agonist therapy; trajectories; treatment duration; treatment patterns