title: Factor analysis of treatment outcomes from a UK specialist addiction service: relationship between the Leeds Dependence Questionnaire, Social Satisfaction Questionnaire and 10-item Clinical Outcomes in Routine Evaluation.
abstract: OBJECTIVE
  To examine the relationship between three outcome measures used by a specialist addiction service (UK): the Leeds Dependence Questionnaire (LDQ), the Social Satisfaction Questionnaire (SSQ) and the 10-item Clinical Outcomes in Routine Evaluation (CORE-10).
  
  
  METHODS
  A clinical sample of 715 service user records was extracted from a specialist addiction service (2011) database. The LDQ (dependence), SSQ (social satisfaction) and CORE-10 (psychological distress) were routinely administered at the start of treatment and again between 3 and 12 months post-treatment. A mixed pre/post-treatment dataset of 526 service users was subjected to exploratory factor analysis. Parallel Analysis and the Hull method were used to suggest the most parsimonious factor solution.
  
  
  RESULTS
  Exploratory factor analysis with three factors accounted for 66.2% of the total variance but Parallel Analysis supported two factors as sufficient to account for observed correlations among items. In the two-factor solution, LDQ items and nine of the 10 CORE-10 items loaded on the first factor >0.41, and the SSQ items on factor 2 with loadings >0.63. A two dimensional summary appears sufficient and clinically meaningful.
  
  
  CONCLUSIONS
  Among specialist addiction service users, social satisfaction appears to be a unique construct of addiction and is not the same as variation due to psychological distress or dependence. Our interpretation of the findings is that dependence is best thought of as a specific psychological condition subsumed under the construct psychological distress.
authors.affiliation: York Trials Unit, University of York, York, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Fairhurst
authors.forename: Jan R
authors.initials: JR
authors.lastname: Böhnke
authors.forename: Rhian
authors.initials: R
authors.lastname: Gabe
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Croudace
authors.forename: Gillian
authors.initials: G
authors.lastname: Tober
authors.forename: Duncan
authors.initials: D
authors.lastname: Raistrick
mesh_terms: D000368:Aged; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011594:Psychometrics; D016320:Substance Abuse Treatment Centers; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000628:therapy; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D006113:United Kingdom; D055815:Young Adult
keywords: factor analysis; patient-reported outcome measure; psychological distress; social satisfaction; substance dependence