Structural characteristics and external correlates of the Working Alliance Inventory-Short Form.

Controversy remains on the psychometric properties of the Working Alliance Inventory-Short Form (WAI-S). In the present study we first examined the factor structure and reliability of WAI-S scores in a sample of 557 Flemish mental health consumers. Subsequently, we investigated the relationship between early alliance quality and client's psychological dysfunctioning (symptomatic distress, interpersonal functioning and personality pathology). Participants completed the Outcome Questionnaire and the Dimensional Assessment of Personality Pathology-Short Form at start of treatment. The WAI-S was completed after the third treatment session. The structure of the WAI-S was examined using confirmatory factor analysis. Four different factor models were compared. Internal consistencies of the scales were ascertained using the Cronbach's alpha coefficient. Pearson correlations were calculated to determine the relationships between alliance ratings and the independent variables. CFA resulted in a two-factor model, with a Bond component (Contact) and a Task-Goal (Contract) component. Reliability of the WAI-S subscale scores proved to be very good. Symptomatic distress, interpersonal dysfunctioning and personality traits were associated to the Contract component of the alliance, but not to the Contact component. Clinical implications, limitations and suggestions for further research are formulated.