title: Predicting persistence to antidepressant treatment in administrative claims data: Considering the influence of refill delays and prior persistence on other medications.
abstract: BACKGROUND
  Many patients with major depressive disorder (MDD) who begin antidepressant treatment discontinue use before for six months, the recommended minimum treatment length. This study sought to identify predictors of six-month antidepressant persistence including predictors utilizing patients' electronic prescription records.
  
  
  METHODS
  Commercially insured children (3-17 years) and adults (18-64 years) with MDD who initiated antidepressant treatment, 1/1/2003-2/28/2010, were assessed for six-month persistence (based on prescriptions' days supply, allowing a 30-day grace period). Antidepressant persistence prediction models were developed separately for children and adults. Two additional measures, days without medication between the first and second antidepressant fill (children and adults) and prior persistence on other medications (adults only), were added to the models, concordance (c) statistics were compared and risk reclassification evaluated.
  
  
  RESULTS
  Among children (n=8837 children) and adults (n=47,495) with MDD, six-month antidepressant persistence was low and varied by age (37%, 18-24 years to 52%, 3-12 and 50-64 years). Independent baseline predictors of persistence were identified, with model c-statistics: children=0.582, adults=0.584. Patients with more days without medication between fills were less likely to be persistent (10-30 vs. 0 days, children: RR=0.72, adults: RR=0.74), as were adults not previously persistent to other medications (RR=0.73).
  
  
  CONCLUSIONS
  The definition of six-month persistence is dependent on correct days supply values and the grace period utilized; potential predictors were limited to measures available in claims data.
  
  
  CONCLUSIONS
  Six-month antidepressant persistence was low and overall prediction of persistence was poor; however, days without medication between fills and prior persistence on other medications marginally improved the ability to predict antidepressant persistence.
authors.affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC, USA. Electronic address: gbushnel@live.unc.edu.
authors.forename: Greta A
authors.initials: GA
authors.lastname: Bushnell
authors.affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Til
authors.initials: T
authors.lastname: Stürmer
authors.affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: White
authors.affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Virginia
authors.initials: V
authors.lastname: Pate
authors.affiliation: Department of Epidemiology, Harvard University, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Sonja A
authors.initials: SA
authors.lastname: Swanson
authors.affiliation: Department of Health Policy and Management, Harvard University, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Azrael
authors.affiliation: Department of Health Science, Northeastern University, Bouvé College of Health Sciences, Boston, MA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Miller
mesh_terms: D000067575:Administrative Claims, Healthcare / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D000928:Antidepressive Agents
keywords: Antidepressants; Persistence; Prediction; Refill delay; Risk reclassification; Selective serotonin reuptake inhibitors