An illustrative case, showing how the AI program helps in

interpreting results on the WMT, MSVT & NV-MSVT: Ruling out dementia as a cause of failure on easy

subtests

Paul Green, February 6, 2010

These slides illustrate the output from the AI program

(Advanced Interpretation)

•The case is a 50 year old separated nurse manager, who supervised 80 staff in a long stay center caring for people with dementia. •She had recently lodged a complaint of incompetence against her immediate supervisor. •She was suddenly confronted by her senior manager with not performing her duties well enough and was sent on short term sick leave.

She was not claiming that she was sick until she was forced to go on sick leave.

• On assessment two months later, she had many memory complaints and said she was worried that she had some form of dementia.

• The referral came from the insurance company which was deciding whether to put her on long term disability.

• She had many losses, including recent breakdown of second marriage and was probably genuinely clinically depressed.

• She was worried about how she could support herself.• She had burnt her bridges with the employer.

Thus, we have a woman who is very knowledgeable about dementia

• She explained to me that people with dementia usually do not have many memory complaints, even though memory is very impaired.

• This woman had an external incentive to appear impaired.

• She was given the TOMM, RDS, WMT, MSVT & NV-MSVT & many other tests.

• Her WMT results are shown on the next slide which is created by the AI program.

• Decision points and outcome are indicated by red lines and boxes.

WMT subtest scores appear at bottom of flow chart

Note that it says “Rule out false negative”

This is explained further in the text summary

Click here for text summary

This woman passed the TOMM (trial 2=47).

• Her RDS score was 7.

• FBS was T82

• Her RBS raw score was 7 (She knew that memory complaints are often low in those with dementia).

Were easy WMT subtests failed because of poor effort or very severe impairment, as seen in some people with dementia?

We investigate further, using the MSVT.

If the impairment were genuine, we would expect another possible dementia profile on the MSVT.

Worse than chance test scores are

present

Criteria A and Bare specified

here

Note 30% score on IR & 20%

on CNS. See summary on

next slide

• So the MSVT scores strongly point towards invalid data and not very severe impairment.

• What would the Nonverbal MSVT show?

There are no worse than chance scores in the NV-MSVT

• The computer also looks at combinations of scores for any worse than chance combinations (e.g. DRA + DRV)

• In this case, the NV-MSVT scores meet criterion A1 and also two out of three B criteria.

• Probable poor effort is indicated by NV-MSVT scores.

Summary

• If we only had the TOMM score, we would conclude good effort.

• With only the WMT scores, we might consider very severe memory impairment, of the type seen in certain dementia patients. The easy-hard difference is big enough that it could reflect actual impairment.

• However, the AI program picks up worse than chance scores on MSVT IR and CNS. It also identifies order violations.

• The NV-MSVT picks up a profile that is relatively rare in people who fail the easy subtests because of dementia but which is frequently seen in known simulators.

• For each test, the flow charts summarize the criteria being applied and show whether they were met or not.

• By selecting “Details”, we can access an explanatory text which helps us to interpret the results.

• Her failure on very easy subtests on the WMT, MSVT and NV-MSVT cannot be explained by genuine severe cognitive deficits or by depression.

• The fact that she passed the TOMM is another example of the lower sensitivity of the TOMM to poor effort compared with the WMT, MSVT and NV-MSVT.

• It was concluded that this woman was depressed but that her cognitive test results were invalid because of major response bias.

• She was advised to avoid management duties and to return to basic nursing duties because this was the second job in which she had failed as a manager.

The AI program is available from Sandra at 780 484 5550 or Pam at drpgreen@telus.net