Meta-Analysis of SIMS Scores of Survivors of Car Accidents and of Instructed Malingerers

Objective: To compare scores on the Structured Inventory of Malingered Symptomatology (SIMS) of normal controls, survivors of motor vehicle accidents (MVAs), and of malingerers instructed to feign post-MVA symptoms.

Method: Mean score and SD was calculated by combining published data on 9 samples of normal controls (combined N=500). Similarly, mean score and SD was calculated by combining published data of 4 samples of persons instructed to feign post-MVA symptoms (combined N=88). Then, ANOVAs were calculated to compare SIMS data of 4 groups: (1) the combined sample of 500 normal controls, (2) 47 patients with minor injuries from MVAs (data published by Capilla Ramírez et al. in 2014), (3) 23 patients injured in high impact MVAs (data published in Cernovsky et al. in 2019), and (4) the combined sample of 88 instructed malingerers.

Results: The ANOVAs were calculated separately for the SIMS total score and then also separately for each of the 5 SIMS scales. The results of these ANOVAs were all significant and, with a few exceptions, post-hoc tests followed the following pattern: (1) the controls obtained significantly lower scores than either of the two groups of patients and also than the instructed malingerers, (2) patients with minor injuries scored lower than those injured in high impact MVAs and also lower than instructed malingerers, (3) patients injured in high impact MVAs had SIMS scores similar to persons instructed to feign post-MVA symptoms (with some exceptions).

Discussion and Conclusions: The overall meta-analytic pattern indicates that patients injured in high impact MVAs and persons instructed to feign post-MVA symptoms tend to obtain similar SIMS scores (with some exceptions) and that both groups score higher than normal controls. This is consistent with the previously published findings that the SIMS consists only of items describing legitimate medical symptoms (SIMS scales NI, AM, AF, P) and of arithmetic and logical tasks and items assessing general knowledge (SIMS LI scale). The SIMS is a pseudoscientific test that fails to differentiate legitimate medical patients from malingerers.

Keywords: car accidents, malingering, SIMS, post-concussion syndrome, whiplash.