Sensitivity and specificity of the indicators of sincere effort of the EPIC lift capacity test on a previously injured population.
METHODS
Randomized control post-test only.


OBJECTIVE
To investigate the reliability and validity of the EPIC Lift Capacity test's indicators of sincere effort.


BACKGROUND
The EPIC Lift Capacity test (ELC) (Employment Potential Improvement Corp., Santa Ana, CA) is a functional evaluation tool used to identify physical limitations involved in lifting and manual materials handling. Identification of insincere effort is an integral component of such functional testing because of the potential secondary gain issues surrounding the various populations typically involved in this form of testing. The purpose of this study was to determine the sensitivity and specificity of the "indicators of sincere effort" of the EPIC Lift Capacity test when used on a previously injured population typical of subjects for which the test is designed.


METHODS
Subjects consisted of 41 volunteers (age 22 to 58 years) with a previously diagnosed musculoskeletal pathology of the spine or extremities. Volunteers were randomized into either the control group, instructed to give a sincere maximum effort, or the experimental group, instructed to give an insincere effort at 50% of their perceived maximum effort. All tests were administered by certified clinical evaluators according to the standardized EPIC Lift Capacity test protocol.-


RESULTS
Overall accuracy in identifying participants' level of effort was 86.84%. The indicators of valid effort exhibited both high positive (94.44%) and negative (80.00%) predictive values. The indicators of valid effort accounted for 94.9% of the total variance in the determination of the subjects' overall effort level. Interrater reliability for agreement of subjects' overall effort was good (interclass correlation coefficient = 0.82).


CONCLUSIONS
Through use of standardized indicators of sincere effort, certified EPIC Lift Capacity test evaluators were able to predict sincerity of effort with a high degree of reliability and validity. The rater's systematicobservational evaluation of effort was shown to be the single best indicator of sincere effort.
Jay
M A
MA
Department of Rehabilitation, Hart County Hospital, Hartwell, Georgia, USA.
Lamb
J M
JM
Watson
R L
RL
Young
I A
IA
Fearon
F J
FJ
Alday
J M
JM
Tindall
A G
AG
D000328:Adult; D019567:Back Injuries / Q000175:diagnosis* / Q000523:psychology; D001696:Biomechanical Phenomena; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006339:Heart Rate; D006801:Humans; D017770:Lifting; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010358:Patient Participation; D010808:Physical Examination / Q000592:standards* / Q000706:statistics & numerical data; D011597:Psychomotor Performance; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity