High Specificity of the Medical Symptom Validity Test in Patients with Very Severe Memory Impairment

This above paper is now available online to NAN members.

Ankush Singhala, Paul Greenb,*, Kunle Ashayea, Kuttalingam Shankara and David Gilla
a Department of Psychiatry, Lister Hospital, Stevenage, UK
b Private Practice in Clinical Neuropsychology, Edmonton, Alberta, Canada

Q) Why does it matter that analysis of the MSVT and NV-MSVT profiles very rarely misclassifies advanced dementia patients as poor effort?

A)  Because these are the most cognitively impaired people we can test.  False positives on an SVT occur if someone tries their best and actually cannot pass. Advanced dementia patients are more likely than anyone else to be false positives on SVTs. If they very rarely produce false positives, it is not plausible that people with lesser impairment will be false positives (e.g. Mild TBI adults).

Note: In this approach the term false positive does not refer to being wrongly classified as a malingerer. It means that the results indicate poor effort and unreliable test data, when the data are actually valid and a result of best effort. This is an important distinction. It is not advisable to say that a poor effort profile on MSVT or NV-MSVT means the person is malingering. We should be meticulous and not infringe on the right of judge and jury to decide intent. It is more conservative and scientifically valid to conclude that results appear reliable or that they appear unreliable due to poor effort.

Archives of Clinical Neuropsychology 2009 24(8):721-728