Detecting Malingered Pain-Related Disability with the Pain Catastrophizing Scale: a Criterion Groups Validation Study.

Objective: Intentional exaggeration of symptoms is a potential problem in contexts where there are financial incentives to appear disabled. Therefore, calibration of tools to accurately evaluate malingering in these contexts is important. The present study used a criterion groups validation design to determine the ability of the Pain Catastrophizing Scale (PCS) to detect Malingered Pain-Related Disability (MPRD). Method: Individuals meeting inclusionary/exclusionary criteria were selected for this study (n = 219) from a larger dataset of chronic pain patients referred for a psychological evaluation. Patients were classified into malingering groups using the Bianchini, Greve, and Glynn classification system for MPRD. PCS T scores were compared in patients who met MPRD criteria and those who showed no indication of malingering on multiple validity tests. Results: No group differences were observed regarding medicolegal and injury characteristics. Group analyses showed that the Not MPRD group had a significantly lower PCS score (Estimated Marginal Mean [EMM] = 62.3) than all other groups. The Probable and Definite MPRD groups (which together comprise the MPRD group) had the highest PCS T scores (EMM = 77.2 and EMM = 83.8, respectively). A PCS T score of 81 was associated with a 7% false-positive (FP) error rate, sensitivity of 47%, likelihood ratio (LR) of 6.7, and a positive predictive value (PPV) of .74 at base rates around 30%. Conclusions: PCS T scores greater than 81 should raise concerns about the validity of the PCS report and provide additional information that can be helpful in identifying intentional symptom exaggeration in patients with chronic pain.