title: Sources of site differences in the efficacy of a multisite clinical trial: the Treatment of SSRI-Resistant Depression in Adolescents.
abstract: Site differences in treatment outcomes are not often highlighted when the results of multisite randomized clinical trials (MRCTs) are reported. The primary analyses of a 6-site MRCT, the Treatment of SSRI-Resistant Depression in Adolescents (TORDIA) study, showed substantial variation by site in the performance of a medication-only condition and a combined medication plus cognitive-behavioral therapy (CBT) condition. Two potential primary causes of site differences in MRCT outcomes were examined in this article: sampling factors, particularly clinical characteristics of participants, and treatment protocol factors, particularly fidelity. The authors found that differences in the clinical characteristics of participants at baseline across site and within site/across conditions were the most salient explanations for site differences and differences within sites across conditions in outcome. Study findings are discussed with respect to the overall study outcomes in TORDIA as well as MRCTs in general.
authors.affiliation: Clinical Psychology Training Consortium, Department of Psychiatry and Human Behavior, The Warren Alpert Medical School of Brown University, USA. Anthony_Spirito@brown.edu
authors.forename: Anthony
authors.initials: A
authors.lastname: Spirito
authors.forename: Kaleab Z
authors.initials: KZ
authors.lastname: Abebe
authors.forename: Satish
authors.initials: S
authors.lastname: Iyengar
authors.forename: David
authors.initials: D
authors.lastname: Brent
authors.forename: Benedetto
authors.initials: B
authors.lastname: Vitiello
authors.forename: Gregory
authors.initials: G
authors.lastname: Clarke
authors.forename: Karen Dineen
authors.initials: KD
authors.lastname: Wagner
authors.forename: Joan
authors.initials: J
authors.lastname: Asarnow
authors.forename: Graham
authors.initials: G
authors.lastname: Emslie
authors.forename: Martin
authors.initials: M
authors.lastname: Keller
mesh_terms: D000293:Adolescent; D015982:Bias; D015928:Cognitive Behavioral Therapy; D003131:Combined Modality Therapy; D003866:Depressive Disorder / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D008297:Male; D015337:Multicenter Studies as Topic / Q000706:statistics & numerical data*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014481:United States
chemical_list: D017367:Selective Serotonin Reuptake Inhibitors