Affiliations: Department of Occupational Therapy, University of
Florida, Box 100164, Gainesville, FL 32610, USA. Tel.: +1 352 846 1021; Fax:
+1 352 846 1042; E-mail: oshechtm@hp.ufl.edu | Pennington Biomedical Research Center, Louisiana State
University (LSU) Pennington, Baton Rouge, LA, USA | Litigation Consultant, Courtroom Sciences, Inc.,
Chicago, IL, USA | Department of Clinical Psychology, University of
Florida, Gainesville, FL, USA
Note: [] Corresponding author
Abstract: The coefficient of variation (CV) is used to determine sincerity of
effort of strength measurements. However, there is a controversy in the
literature concerning its validity and effectiveness. We used a meta-analytic
approach and calculated the effect size between maximal and submaximal efforts
for the CV of grip, elbow flexion and knee extension. We summarized findings
concerning stability, sensitivity and specificity of the CV. We found large
effect sizes (d ⩾ 0.8) for all comparisons indicating
that submaximal efforts were more variable than maximal efforts. We also found
large error rates and low stability of the CV. The error rates and stability
values of the CV are unacceptable from both a clinical and a medico-legal
standpoint. Therefore, the use of the CV for assessing sincerity of effort
needs to be questioned.
Keywords: Grip strength, meta-analysis, coefficient of variation, sincerity of effort
