Further Validation of the Response Inconsistency Scale for the Personality Inventory for DSM-5

Area of Science:

• Psychological Assessment
• Clinical Psychology
• Personality Disorders

Background:

• Protocol validity is crucial for accurate personality test interpretation in clinical settings.
• Inconsistent responding measures help identify careless or random response patterns.
• The Inconsistency scale (INC) was previously developed for the Personality Inventory for DSM-5 (PID-5).

Purpose of the Study:

• To validate the adaptability of INC item pairs across different populations, translations, and versions of the PID-5.
• To examine the diagnostic utility of a shortened INC scale (INC-S) for the 100-item PID-5.
• To provide further evidence for the reliability of the INC and INC-S in detecting invalid test protocols.

Main Methods:

• Study 1: Assessed diagnostic utility of INC-S with optimum cut scores for the 100-item PID-5.
• Study 2: Cross-validated INC-S and compared its utility to the full INC scale using the complete PID-5.
• Study 3: Evaluated INC and INC-S diagnostic utility with a German PID-5 translation in student and patient samples.

Main Results:

• The INC and INC-S demonstrated high diagnostic utility in discriminating between random and genuine PID-5 protocols.
• Optimal cut scores were identified for the INC-S, enhancing its practical application.
• Validation across different populations, translations (German), and PID-5 versions confirmed the robustness of the INC scales.

Conclusions:

• The INC and INC-S scales provide robust and reliable methods for assessing protocol validity in PID-5 assessments.
• These scales are adaptable and effective across diverse samples, languages, and test versions.
• The findings support the use of INC and INC-S in clinical practice to ensure accurate personality assessment.