Cognitive performance after mild traumatic brain injury: the impact of poor effort on test results and its relation to distress, personality and litigation.
OBJECTIVE
To compare consecutive Mild Traumatic Brain Injury (MTBI) patients with and without adequate effort on cognitive performance, litigation status, fatigue, distress and personality.


METHODS
(Neuro)psychological assessment was done 6 months post-injury in 110 patients from a cohort of 618 consecutive MTBI patients aged 18-60, who attended the emergency department of our level I trauma centre. Effort was tested with the Amsterdam Short Term Memory test.


RESULTS
Thirty patients (27%) failed the effort test. Poor effort was associated with significantly poorer scores on seven out of eleven measures, covering all tested domains. Poor effort was associated with lower educational level and changes in work status, but not litigation. Furthermore, poor effort was related to high levels of distress, Type-D personality and fatigue.


CONCLUSIONS
Even in a sample of non-referred MTBI patients, poor effort was common and was strongly associated with inferior test performance. These findings imply that effort testing should be part of all cognitive assessments, also outside mediolegal settings. Behavioural factors like distress and personality should be considered as potential threats to the validity of neuropsychological testing after MTBI.
Stulemeijer
Maja
M
Department of Medical Psychology, Radboud University Nijmegen Medical Centre, The Netherlands. M.Stulemeijer@neuro.umcn.nl
Andriessen
Teuntje M J C
TM
Brauer
Jolanda M P
JM
Vos
Pieter E
PE
Van Der Werf
Sieberen
S
D000293:Adolescent; D000328:Adult; D001288:Attention; D001930:Brain Injuries / Q000523:psychology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology; D015331:Cohort Studies; D035881:Compensation and Redress; D005221:Fatigue / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010551:Personality; D015203:Reproducibility of Results; D013315:Stress, Psychological / Q000523:psychology*