title: The dependability of alliance assessments: the alliance-outcome correlation is larger than you might think.
abstract: OBJECTIVE
  To examine the dependability of alliance scores at the patient and therapist level, to evaluate the potential causal direction of session-to-session changes in alliance and depressive symptoms, and to investigate the impact of aggregating the alliance over progressively more sessions on the size of the alliance-outcome relationship.
  
  
  METHODS
  We used data from a study (N = 45 patients; N = 9 therapists) of psychotherapy for major depressive disorder in which the alliance was measured at every treatment session to calculate generalizability coefficients and to predict change in depressive symptoms from alliance scores. Two replication samples were also used.
  
  
  RESULTS
  At the therapist level, a large number of patients (about 60) per therapist is needed to provide a dependable therapist-level alliance score. At the patient level, generalizability coefficients revealed that a single assessment of the alliance is only marginally acceptable. Very good (>.90) dependability at the patient level is only achieved through aggregating 4 or more assessments of the alliance. Session-to-session change in the alliance predicted subsequent session-to-session changes in symptoms. Evidence for reverse causation was found in later-in-treatment sessions, suggesting that only aggregates of early treatment alliance scores should be used to predict outcome. Session 3 alliance scores explained 4.7% of outcome variance, but the average of Sessions 3-9 explained 14.7% of outcome variance.
  
  
  CONCLUSIONS
  Adequate assessment of the alliance using multiple patients per therapist and at least 4 treatment sessions is crucial for fully understanding the size of the alliance-outcome relationship.
authors.affiliation: Department of Psychiatry, University of Pennsylvania, 3535 Market Street, Philadelphia, PA 19104, USA. crits@mail.med.upenn.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Crits-Christoph
authors.forename: Mary Beth Connolly
authors.initials: MB
authors.lastname: Gibbons
authors.forename: Jessica
authors.initials: J
authors.lastname: Hamilton
authors.forename: Sarah
authors.initials: S
authors.lastname: Ring-Kurtz
authors.forename: Robert
authors.initials: R
authors.lastname: Gallop
mesh_terms: D000293:Adolescent; D000328:Adult; D003865:Major Depressive Disorder / Q000523:psychology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011369:Professional-Patient Relations; D011582:Psychological Theory; D011613:Psychotherapy; D016896:Treatment Outcome