The premorbid adjustment scale structured interview (PAS-SI): preliminary findings.

Background: The Premorbid Adjustment Scale (PAS) is a widely used rating scale to assess premorbid functioning retrospectively. Despite its widespread use there is no published structured interview (SI) schedule and little is known about the reliability of the instrument.

Objective: To design and test the reliability of a structured interview schedule for the PAS, the PAS-SI, across different cultures.

Methods: Starting from PAS items and response options, questions were prepared that lead to a response option. Instructions to skip certain items, for example, quality of friendships after a person noted no friends, were provided. Additional instructions were prepared including guidelines to determine the first onset of psychotic symptoms thereby ensuring that the interview is only directed to premorbid functioning. The interview was translated from English into Hebrew, Portuguese, French, Dutch (Flemish), Turkish, Italian, Lithuanian, Greek, Russian, Ukrainian, and Romanian and tested for inter-rater reliability "in nine of these languages". Eighty-four psychiatrists from 10 different countries acted as raters in a role-play assisted training session after which they rated the PAS-SI in their native language. The intra-class correlation was computed to index reliability.

Results: The weighted intra-class correlation for absolute agreement and consistency was .77.

Conclusions: The PAS-SI provides reliable and consistent data on premorbid functioning.