The Iowa Personality Disorder Screen Preliminary Results of the Validation of a Self-Administered Version in a Dutch Population

The internal consistency, test-retest reliability, and predictive validity of the Iowa Personality Disorder Screen (IPDS) as a screening instrument for personality disorders (PDs) were studied in 195 Dutch psychiatric outpatients, using the SCID-II as the gold standard. All patients completed a self-administered version of the IPDS. Internal consistency was moderate (0.64), and the test-retest reliability was good (0.87). According to the SCID-II, 97 patients (50%) had at least one personality disorder (PD). The IPDS correctly classified 81.0 percent of all participants in the category PD present/absent. The sensitivity and specificity were 77% and 88%, respectively. Positive and negative predictive values were 83% and 79%. Test-retest reliability after a 2-week interval was 0.87. These results are comparable with those reported in earlier studies with respect to the interview version of the IPDS and more promising than previously reported results obtained with a self-report version of the IPDS. Therefore, it is concluded that a self-report version of the IPDS may be useful as a screening measure for determining the presence/absence of PD in a population of psychiatric outpatients.