Nonverbal Medical Symptom Validity Test

NV-MSVT was provided free to WMT and MSVT users for a two-year period.

As of January 30, 2008, the NV-MSVT is now sold as a kit. The NV-MSVT kit includes

  1. A 115 page Test Manual with full color covers, spiral bound.
  2. NV-MSVT program and update on CD,
  3. Assistance with installation &
  4. 30 uses of the NV-MSVT.

NV-MSVT has no words on screen. It only has artist drawn images. It takes 5 minutes and has actual memory measures as well as validity/effort checks.

See table at bottom of page showing how dementia patients and simulators can be differentiated from each other, using the NV-MSVT.

The NV-MSVT discriminates between dementia and poor effort: The NV-MSVT is not like other effort tests. For example, if someone were to fail TOMM, ASTM or VSVT, it is impossible to differentiate between dementia or poor effort as the underlying cause of the failure, if we rely on the test scores alone.

With the (nonverbal) NV-MSVT, however, in many cases we are able to differentiate between invalid data owing to poor effort versus dementia. People with dementia fail the NV-MSVT and people asked to simulate fail it but they do so in different ways. The table below shows how:

  • Simulators and good effort volunteers were discriminated from each other with 100% accuracy using Principle A.
  • The majority of simulators were accurately identified by principles B1 and B2 as possible simulators (orange/red zone).
  • The majority of dementia cases were accurately identified as possible dementia cases (green zone)
  • If both B1 & B2 are failed, then the odds that it is a case of simulation versus dementia are 15 to 1
  • This still leaves us with some cases where clinical correlation is needed to decide whether data are valid or not but, with other tests, no such discrimination is possible.

New data on the NV-MSVT.

Principles A, B1 and B2 are used within the NV-MSVT program
for discriminating between profiles of simulators and dementia patients
Principle A:
Pass or Fail
easy subtests
When NV-MSVT is
failed, principles
B1 (Pinocchio)
and B2 are used to
define a possible
dementia profile
Group
A
B1
B2
40 GOOD EFFORT VOLUNTEERS
40 VOLUNTEER SIMULATORS
42 PATIENTS WITH DEMENTIA
PASS NV-MSVT
N/A
N/A
40
0
7
1 NO
NO
0
1
27
FAIL NV-MSVT
2 NO
YES
0
2
1
3 YES
NO
0
8
5
4 YES
YES
0
29
2
Percentage with possible simulator profile (orange)
2, 3 or 4 above
0%
97.5%
19%
Percentage failing NV-MSVT, and also failing on both principles B1 & B2 (red)
4 above
0%
72.5%
5%
i.e. 95% specificity in dementia.
Percentage failing NV-MSVT, and also failing on both principles B1, B2 & B3
0%
53%
0%
i.e. We can achieve 100% specificity in dementia if we wish.
Do you know any effort test that does this?

Principles A, B1 and B2 for differentiating between simulators and people with dementia, using the NV-MSVT program are made explicit within the program. They are based on differences observed between people asked to simulate memory impairment and people with dementia.

A third variable which has been found to differentiate between dementia and simulators is the Standard Deviation of the scores on DR, CNS, DRA & DRV. If the SD is 12 or higher, it is more likely to be a case of poor effort than dementia. This is principle B3.<

In the above study, only 5% of dementia cases failed NV-MSVT and also failed on principles B1 & B2. However, 72.5% of simulators did so.

There were no cases of dementia who failed NV-MSVT and also failed on principles B1, 2 and 3. However, about 53% of simulators did so. Hence, using all these criteria for poor effort (fail NV-MSVT and also meet B1, 2 & 3) leads to no false positives for poor effort in dementia. With the exception of WMT and MSVT, no other effort tests can discriminate between dementia and simulators this well.