Problems in developing an instrument for the rapid assessment of personality status

Abstract

Purpose: To assess the validity of a quick assessment instrument (10 minutes) for assessing personality status, the Rapid Personality Assessment Schedule (PAS-R).

Subjects and methods: The PAS-R was evaluated in psychotic patients recruited in one of the centres involved in a multicentre randomised controlled trial of intensive vs standard case management (the UK700 case management trial). Patients were assessed using both a full version of the PAS (PAS-I - ICD version) and the PAS-R. The weighted kappa statistic was used to gauge the (criterion-related) validity of the PAS-R using the PAS-I as the gold standard. Both measure code personality status using a four-point rating of severity in addition to recording individual categories of personality disorder.

Results: One hundred fifty-five (77%) of 201 patients recruited were assessed with both instruments. The weighted kappa statistic was 0.31, suggesting only moderate agreement between the PAS-I and PAS-R instruments under the four-point rating format, and 0.39 for the dichotomous personality disorder/no disorder separation. The sensitivity (64%) and specificity (82%) of the PAS-R in predicting PAS-I personality disorder were as satisfactory as for other screening instruments but still somewhat disappointing, and the PAS-R had an overall diagnostic accuracy of 78%.

Conclusion: The PAS-R is a quick and rough method of detecting personality abnormality but is not a substitute for a fuller assessment.