Evaluation of posturography in the detection of malingering subjects.

OBJECTIVE

This study aimed to test the performance of proposed methods for detecting malingering subjects on computerized dynamic posturography using one subject group in three situations (normal, malingering, vestibular weakness).

STUDY DESIGN

The study design was a prospective, blinded study.

SETTING

The study was conducted at a university hospital.

PATIENTS

Volunteer subjects aged 20-59 years of age participated.

INTERVENTIONS

Computerized dynamic posturography was performed under three situations: best effort, faking vestibular weakness, and transient induced vestibular weakness with bilateral simultaneous caloric irrigation.

MAIN OUTCOME MEASURES

Measured was identification of situation (normal, malingering, induced vestibular weakness) by each of three detection methods: blinded clinical scoring, a set of formulae, and a set of variables (the latter two methods proposed previously by other investigators).

RESULTS

Each method performed well. In three-way discrimination, the formulae and clinical scoring each correctly identified approximately 75% of trials. In two-way discrimination (malingering vs. induced vestibular weakness), the best combination of variables slightly outperformed clinical scoring (0.93 vs. 0.88 ROC [receiver operating characteristic] curve area).

CONCLUSIONS

Computerized dynamic posturography can distinguish malingering in normal subjects from trials performed with best effort or after binaural simultaneous caloric irrigation. The accuracy of blinded clinical scoring was comparable to that of two objective detection methods.