The mediating effects of effort upon the relationship between head injury severity and cognitive functioning.
OBJECTIVE
Given that poor effort may have a profound impact upon the results of neuropsychological assessment, it is of critical importance that assessment of effort is incorporated into the interpretation of a patient's neuropsychological profile. The current study examines the relationship between head injury severity (as measured by length of post-traumatic amnesia) and level of cognitive functioning in patients passing or failing a test of effort (Test of Malingered Memory).


METHODS
A cross-sectional correlational design was employed in a consecutive cohort of 78 persons with ongoing compensation claims.


METHODS
Head injury severity was assessed by duration of post-traumatic amnesia. All participants received a clinical interview followed by neuropsychological assessment.


RESULTS
A systematic and interpretable negative correlation between head injury severity and intellectual and memory functioning was demonstrated in persons passing the test of effort. However, in persons failing the test of effort no such relationships were demonstrated.


CONCLUSIONS
The implications for the interpretation of neuropsychological test data are discussed. It is strongly recommend that valid interpretation of neuropsychological assessment data should include consideration of at least one test of effort.
University Hospital, Edgbaston, Birmingham, UK. neuropsychology@blueyonder.co.uk
Alan
A
Moss
Christopher
C
Jones
Dene
D
Fokias
David
D
Quinn
D000293:Adolescent; D000328:Adult; D000647:Amnesia / Q000523:psychology; D003071:Cognition; D015331:Cohort Studies; D006259:Craniocerebral Trauma / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008568:Memory; D008875:Middle Aged; D009042:Motivation; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D013997:Time Factors; D014888:Wechsler Scales