title: Space-Time Cluster Analysis to Detect Innovative Clinical Practices: A Case Study of Aripiprazole in the Department of Veterans Affairs.
abstract: To identify space-time clusters of changes in prescribing aripiprazole for bipolar disorder among providers in the VA.
  
  
  
  VA administrative data from 2002 to 2010 were used to identify prescriptions of aripiprazole for bipolar disorder. Prescriber characteristics were obtained using the Personnel and Accounting Integrated Database.
  
  
  
  We conducted a retrospective space-time cluster analysis using the space-time permutation statistic.
  
  
  
  All VA service users with a diagnosis of bipolar disorder were included in the patient population. Individuals with any schizophrenia spectrum diagnoses were excluded. We also identified all clinicians who wrote a prescription for any bipolar disorder medication.
  
  
  
  The study population included 32,630 prescribers. Of these, 8,643 wrote qualifying prescriptions. We identified three clusters of aripiprazole prescribing centered in Massachusetts, Ohio, and the Pacific Northwest. Clusters were associated with prescribing by VA-employed (vs. contracted) prescribers. Nurses with prescribing privileges were more likely to make a prescription for aripiprazole in cluster locations compared with psychiatrists. Primary care physicians were less likely.
  
  
  
  Early prescribing of aripiprazole for bipolar disorder clustered geographically and was associated with prescriber subgroups. These methods support prospective surveillance of practice changes and identification of associated health system characteristics.
authors.affiliation: Group Health Research Institute, Seattle, WA.|Department of Health Services Research, School of Public Health, University of Washington, Seattle, WA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Penfold
authors.affiliation: Department of Veterans Affairs Center for Healthcare Organization & Implementation Research (CHOIR), VA Boston Healthcare System-152M, Boston, MA.|Boston University School of Public Health, Health Law, Policy & Management, Boston, MA.
authors.forename: James F
authors.initials: JF
authors.lastname: Burgess
authors.affiliation: Department of Surgeries, Massachusetts General Hospital, Boston, MA.
authors.forename: Austin F
authors.initials: AF
authors.lastname: Lee
authors.affiliation: Department of Veterans Affairs Center for Healthcare Organization & Implementation Research (CHOIR), VA Boston Healthcare System-152M, Boston, MA.|Department of Mathematical Sciences, Bentley University, Waltham, MA.
authors.forename: Mingfei
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Veterans Affairs Center for Healthcare Organization & Implementation Research (CHOIR), VA Boston Healthcare System-152M, Boston, MA.|Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Miller
authors.affiliation: Department of Veterans Affairs Center for Healthcare Organization & Implementation Research (CHOIR), VA Boston Healthcare System-152M, Boston, MA.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Nealon Seibert
authors.affiliation: U. S. Department of Veterans Affairs, Pharmacy Benefits Management Services (10P4P), Hines, IL.
authors.forename: Todd P
authors.initials: TP
authors.lastname: Semla
authors.affiliation: Department of Veterans Affairs Center for Healthcare Organization & Implementation Research (CHOIR), VA Boston Healthcare System-152M, Boston, MA.|Boston University School of Public Health, Health Law, Policy & Management, Boston, MA.
authors.forename: David C
authors.initials: DC
authors.lastname: Mohr
authors.affiliation: Boston University School of Public Health, Health Law, Policy & Management, Boston, MA.
authors.forename: Lewis E
authors.initials: LE
authors.lastname: Kazis
authors.affiliation: Department of Veterans Affairs Center for Healthcare Organization & Implementation Research (CHOIR), VA Boston Healthcare System-152M, Boston, MA.|Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Bauer
mesh_terms: D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D000068180:Aripiprazole / Q000008:administration & dosage / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009726:Nurses / Q000706:statistics & numerical data; D058007:Physicians, Primary Care / Q000706:statistics & numerical data; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011570:Psychiatry / Q000706:statistics & numerical data; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013029:Space-Time Clustering; D014481:United States; D014493:United States Department of Veterans Affairs; D014728:Veterans
chemical_list: D014150:Antipsychotic Agents; D000068180:Aripiprazole
keywords: 
  VA
  ; antipsychotic; diffusion; innovation; space-time cluster