An Inventory of Problems (IOP) Study of Symptom and Performance Validity in a Sample of Driver’s License Renewal or Reinstatement Applicants

This study aimed to investigate the specificity of the Inventory of Problems (IOP) tests, specifically the IOP-29 and its memory module (IOP-M), in a high-stakes environment. The study involved 114 Italian adults who applied for the renewal or reinstatement of their driver’s license after it had been revoked due to psychiatric, cognitive, or legal issues. The IOP-29 and the IOP-M were administered alongside other tests. Data analysis revealed very few positive results for both the IOP-29 and the IOP-M, indicating high specificity in detecting a possible negative response bias. In fact, the false positive rate (or, more accurately, the presumably false positive rate) was less than 5% for each of the two IOP components, meaning that the specificity for the standard cutoff values of each IOP component (i.e., IOP-29 ≥ 0.50 and IOP-M ≤ 29) was above 0.95. Taken together, these results contribute to the growing body of research supporting the use of the IOP-29 and IOP-M in applied settings where mild cognitive impairment might be present. However, further studies are needed to validate these results in populations with moderate or severe cognitive impairment.