Accuracy of the Modified Somatic Perception Questionnaire and Pain Disability Index in the detection of malingered pain-related disability in chronic pain.

The Modified Somatic Perception Questionnaire (MSPQ) and the Pain Disability Index (PDI) are both popular clinical screening instruments in general orthopedic, rheumatologic, and neurosurgical clinics and are useful for identifying pain patients whose physical symptom presentations and disability may be non-organic. Previous studies found both to accurately detect malingered pain presentations; however, the generalizability of these results is not clear. This study used a criterion groups validation design (retrospective cohort of patients with chronic pain, n = 328) with a simulator group (college students, n = 98) to determine the accuracy of the MSPQ and PDI in detecting Malingered Pain Related Disability. Patients were grouped based on independent psychometric evidence of MPRD. Results showed that MSPQ and PDI scores were not associated with objective medical pathology. However, they accurately differentiated Not-MPRD from MPRD cases. Diagnostic statistics associated with a range of scores are presented for application to individual cases. Data from this study can inform the clinical management of chronic pain patients by screening for psychological overlay and malingering, thus alerting clinicians to the possible presence of psychosocial obstacles to effective treatment and triggering further psychological assessment and/or treatment.