Standardization of the German 16-item short version of the Inventory of Personality Organization (IPO-16).
Objectives: The 16-item short version of the Inventory of Personality Organization (IPO-16) is a self-report measure assessing the severity of personality dysfunction. This study provides representative norms and determines the smallest real difference value for the IPO-16.
Methods: Standardization of the IPO-16 was based on a representative survey among the German general population (N = 2502). Retest reliability and the smallest real difference were assessed in a separate longitudinal online survey, whereby participants completed the IPO-16 three times at time intervals of 2 months (N = 495).
Results: The average IPO-16-mean score in the general population was 1.87. The influence of age and sex was small, albeit statistically significant.We therefore developed sex- and age-specific norms. The average retest reliability across 2 months was .85, and the smallest real difference was 0.66.
Conclusions: The IPO-16 is a well-validated, and now standardized, screening instrument for the assessment of severity of personality dysfunction. It can be recommended for use in research and practice.