title: Measuring Medication Adherence in Pediatric Cancer: An Approach to Validation.
abstract: This study described the prospective relationship between pharmacological and behavioral measures of 6-mercaptopurine (6MP) medication adherence in a multisite cohort of pediatric patients diagnosed with cancer ( N  = 139).
  
  
  
  Pharmacological measures (i.e., metabolite concentrations) assessed 6MP intake. Behavioral measures (e.g., electronic monitoring) described adherence patterns over time.
  
  
  
  Three metabolite profiles were identified across 15 months: one group demonstrated low levels of both metabolites (40.8%) consistent with nonadherence and/or suboptimal therapy; two other groups demonstrated metabolite clusters indicative of adequate adherence (59.2%). Those patients whose metabolite profile demonstrated low levels of both metabolites had consistently lower behavioral adherence rates.
  
  
  
  To our knowledge, this was the first study to prospectively validate a pharmacological measure of medication adherence with a behavioral adherence measure in a relatively large sample of pediatric patients with cancer. Using multiple methods of adherence measurement could inform clinical care and target patients in need of intervention.
authors.affiliation: Department of Psychology, University of Cincinnati, Cincinnati, OH, USA.|Center for Adherence and Self-Management, Cincinnati Children's Hospital Medical Center, OH, USA.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Rohan
authors.affiliation: Department of Pediatrics, University of Cincinnati School of Medicine, OH, USA.|Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Cente, OH, USA.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fukuda
authors.affiliation: Division of Oncology, The Children's Hospital of Philadelphia, PA, USA.|Perelman School of Medicine, University of Pennsylvani, Philadelphia, PA, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Alderfer
authors.affiliation: Center for Pediatric Psychiatry, Children's Medical Center Dallas, Texas, USA.|UT Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Crista
authors.initials: C
authors.lastname: Wetherington Donewar
authors.affiliation: Department of Psychiatry, Western Psychiatric Institute and Clinic, Pittsburgh, PA, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Ewing
authors.affiliation: Division of General Pediatrics, Children's Hospital Los Angeles, CA, USA.|Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Ernest R
authors.initials: ER
authors.lastname: Katz
authors.affiliation: Division of Psychosocial Oncology, Dana-Farber Cancer Institute and Boston Children's Hospital, Boston, MA, USA.
authors.forename: Anna C
authors.initials: AC
authors.lastname: Muriel
authors.affiliation: Department of Pediatrics, University of Cincinnati School of Medicine, OH, USA.|Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Cente, OH, USA.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Vinks
authors.affiliation: Department of Psychology, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Drotar
mesh_terms: D000293:Adolescent; D000328:Adult; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy*; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D000964:Antimetabolites, Antineoplastic; D015122:Mercaptopurine
keywords: adherence; cancer; metabolites; pediatrics; pharmacology