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Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
Zasler, Nathan
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Zasler, Nathan

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  • 1. EFFECT OF EFFORT ON POST-TBI OUTCOMES RESEARCH: PRACTICAL AND RESEARCH IMPLICATIONS NATHAN D. ZASLER, MD CEO & MEDICAL DIRECTOR, CONCUSSION CARE CENTRE OF VIRGINIA AND TREE OF LIFE SERVICES CLINICAL PROFESSOR, PM&R, VCU, RICHMOND, VA., USA AND ASSOCIATE PROFESSOR, PM&R, UVA, CHARLOTTESVILLE, VA., USA CHAIRPERSON, IBIA
  • 2. EDUCATIONAL OBJECTIVES <ul><li>Understand the importance of assessing effort in the context of interpreting test validity in both clinical and research contexts  </li></ul><ul><li>Identify constructs represented by symptom validity tests and make informed decisions regarding how to incorporate such constructs in TBI clinical care and research  </li></ul><ul><li>Describe some of the major controversies relating to the use of effort tests and their interpretation in TBI care and research </li></ul><ul><li>Outline areas for further research and inquiry germane to the need and use of effort testing in the context of both TBI clinical care and research </li></ul>
  • 3. WHY IS ASSESSMENT OF EFFORT IMPORTANT? <ul><li>Without satisfactory effort, neuropsychological test results and for that matter any ability test data are going to yield invalid reflections of a person’s true capacities. </li></ul><ul><li>Poor effort on testing and exaggeration of cognitive complaints are commonplace. </li></ul>
  • 4. WHY IS ASSESSMENT OF EFFORT IMPORTANT? <ul><li>TBI clinical practice, as well as outcomes research must therefore develop and integrate well-validated measures of effort if there is a desire to generate data demonstrating the true capacities of those be evaluated. </li></ul>
  • 5. WHY IS ASSESSMENT OF EFFORT IMPORTANT? <ul><li>Literature shows that poor effort is seen in numerous different contexts including but not limited to: </li></ul><ul><ul><li>claims of cognitive deficits from any source including TBI </li></ul></ul><ul><ul><li>professional athletes pre- and post-concussion </li></ul></ul><ul><ul><li>university students seeking accommodations for ADHD or learning disabilities </li></ul></ul><ul><ul><li>prisoners facing sentencing </li></ul></ul><ul><ul><li>adults volunteering for normative studies or children in school. </li></ul></ul>
  • 6. SPECTRUM OF EFFORT ON COGNITIVE TESTING <ul><li>Poor Effort Adequate Effort Outstanding Effort </li></ul>
  • 7. REASONS TO TEST FOR EFFORT <ul><li>Poor effort during testing is, unfortunately, common (Larrabee, 2003; Mittenberg, Patton, Canyock, & Condit, 2002) </li></ul><ul><li>The effect of poor effort on neuropsychological test results is major (Vickery et al., 2001) </li></ul><ul><li>The effect of poor effort dwarfs the effect of mild traumatic brain injuries or other conditions that have modest effects on cognitive functioning. </li></ul>
  • 8. REASONS TO TEST FOR EFFORT <ul><li>There are well-validated tests for detecting poor effort that have low false positive rates. </li></ul><ul><li>In forensic practice, must address causation and rule-out factors that might lead to incorrect inferences or interpretations. </li></ul><ul><li>It is considered standard practice in forensic psychology and neuropsychology to do employ effort as well as response bias measures. </li></ul><ul><li>The same should be said for and occur in clinical practice and in outcomes research </li></ul>
  • 9. EXTERNAL INCENTIVES AND INFLUENCE ON EFFORT <ul><li>When there is compensation being received or when there is potential compensation to be received, then effort tends to be adversely affected at a much higher rate. </li></ul><ul><li>WC, SSDI and PI cases are red flags for increased risk of sub-optimal effort. </li></ul><ul><li>When there are reasons / incentives to look more impaired people will attempt to do so… </li></ul>
  • 10.  
  • 11. SPORTS CONCUSSION RESEARCH AND EFFORT <ul><li>Peyton Manning who plays quaterback for the Colts admitted recently to intentionally scoring low on NFL baseline concussion tests so that he can continue to play again after a future injury after being retested. </li></ul><ul><li>Several NFL players said they too purposely performed poorly on the test so they would not be benched after concussive injuries. </li></ul><ul><li>Brings into question sports concussion research using players as their own controls in the absence of effort testing. </li></ul>
  • 12. ADVERSE EFFECTS ON NEUROCOGNITIVE TEST PERFORMANCE
  • 13. CLINICAL AND RESEARCH WORK IN PERSONS WITH TBI MUST ALSO CONSIDER: <ul><li>Misattribution bias </li></ul><ul><li>Diagnosis threat and nocebo effect </li></ul><ul><li>Pre-existing psychological history </li></ul><ul><li>Involvement in litigation and risk for symptom magnification and in rare cases malingering </li></ul><ul><li>Cognitive hypochondriasis </li></ul><ul><li>Symptom minimization </li></ul>
  • 14. IMPORTANCE OF ASSESSING RESPONSE BIAS <ul><li>Formal measures of response bias should be interspersed throughtout neuropsychological exam including use of embedded as well as free-standing measures NAN </li></ul><ul><ul><li>(Bush et al, 2005), AACN(Heilbronner et al, 2009). </li></ul></ul><ul><li>Need to understand that response bias is not constant across an exam </li></ul><ul><li>Need to understand that response biases present differently across patients </li></ul>
  • 15. HOW TO SELECT EFFORT MEASURES <ul><li>Should be brief and ideally embedded as this best allows for continuous sampling </li></ul><ul><li>Choose measures with high effectiveness as assessed by sensitivity while maintaining adequate specificity </li></ul><ul><li>Low to moderate sensitivity tests can be used to “rule in” but not “rule out” response bias </li></ul><ul><li>Cut-off scores should be set to protect credible patients at the sacrifice of sensitivity – thus a failing score is more relevant than a passing score </li></ul>
  • 16. HOW TO SELECT EFFORT TESTS <ul><li>Employ effort tests that tap various neurocognitive domains </li></ul><ul><li>Select tests that are not strongly correlated with each other </li></ul><ul><li>Consider group being studied and choose tests that lessen risk for false positive identification as “poor effort” on particular tests </li></ul><ul><li>Consider risk of patient education or coaching regarding specific effort measures – don’t always use same tests and try and use less common ones as well. </li></ul>
  • 17. TYPES OF EFFORT TESTS <ul><li>Forced choice </li></ul><ul><li>Non-forced choice </li></ul><ul><li>Freestanding </li></ul><ul><li>Embedded </li></ul>
  • 18. COGNITIVE EFFORT TESTS: FREESTANDING <ul><li>REY 15 ITEM MEMORY TEST </li></ul><ul><li>REY DOT COUNTING TEST </li></ul><ul><li>DIGIT RECOGNITION TEST (HISCOCK) </li></ul><ul><li>COMPUTERIZED ASSESSMENT OF RESPONSE BIAS (CARB) </li></ul><ul><li>TEST OF MALINGERED MEMORY (TOMM) </li></ul><ul><li>WORD MEMORY TEST (WMT), MSVT, NV-MSVT, MCI </li></ul><ul><li>WORD COMPLETION MEMORY TEST (WCMT) </li></ul><ul><li>VICTORIA SYMPTOM VALIDITY TEST (VSVT) </li></ul>
  • 19. EMBEDDED EFFORT MEASURES <ul><li>Reliable Digit Span </li></ul><ul><li>Digit Span Scaled Score </li></ul><ul><li>Logical Memory Rarely Missed Index </li></ul><ul><li>Finger Tapping Test </li></ul><ul><li>Booklet Category Test </li></ul>
  • 20. FORCED CHOICE TESTS <ul><li>Task is to recognize previously seen material from two choices </li></ul><ul><li>Recognition is substantially easier than free recall. </li></ul><ul><li>Can compare performance across tests to look for non-organic patterns. </li></ul><ul><li>Sensitive to feigned deficits in memory. </li></ul><ul><li>Examine performance relative to chance or set cut-offs below which few credible patients will score. </li></ul>
  • 21. NON-FORCED CHOICE TESTS <ul><li>Standard cognitive tests that are already in an existing neurocognitive battery such as: </li></ul><ul><ul><li>WAIS-III digit span </li></ul></ul><ul><ul><li>RAVLT recognition equation </li></ul></ul><ul><ul><li>Finger tapping </li></ul></ul><ul><ul><li>Stroop test </li></ul></ul><ul><ul><li>WMS-III logical memory </li></ul></ul>
  • 22. CONTROVERSIES IN EFFORT AND RESPONSE BIAS TESTING IN PERSONS WITH TBI <ul><li>What causes sub-optimal effort? </li></ul><ul><li>How, if at all, do fatigue, depression, anxiety, pain, interest in task, cultural background, among other factors, influence effort testing results? </li></ul><ul><li>What does “failure” on an effort test mean? </li></ul><ul><li>How does response bias correlate with effort? </li></ul><ul><li>What factors influence interpretation of response bias measures? </li></ul>
  • 23. FUTURE DIRECTIONS <ul><li>Increased appreciation of the need for inclusion of effort and response bias measures in clinical and research practice. </li></ul><ul><li>Expanded research on development of effort measures that are specific to poor effort and not impacted by other factors such as dementia. </li></ul><ul><li>Further research on development of tests that are not impacted by age, demographics or sex </li></ul><ul><li>Collection of performance data on specific sub-groups of patients including those with affective disorders, pain, somatoform disorders, fatigue, among others. </li></ul>
  • 24. Join IBIA in Edinburgh, Scotland for the Ninth World Congress of the International Brain Injury Association March 21-25, 2012 Visit www.internationalbrain.org
  • 25.  
  • 26. THE END <ul><li>DR. ZASLER’s E-MAIL: </li></ul><ul><li>[email_address] </li></ul>
  • 27.  

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