Determination of the optimal cutoff values and validity of the Purdue Pegboard Test

Abstract

Introduction The Purdue Pegboard Test (PPT) is crucial for assessing fine dexterity of patients with hand injury. Determining the PPT cutoff value is needed to distinguish patients with impaired hand dexterity from those with unimpaired hand dexterity. The aim of this article is to examine the construct validity of PPT and to determine its cutoff values for patients with hand injuries. Method The PPT and Disabilities of Arm Shoulder and Hand Questionnaire Turkish version (DASH-T) were used to measure hand dexterity. To examine construct validity, we measured the correlation between PPT and DASH-T. The cutoff values were determined using the receiver operating characteristic (ROC) curve generated with sensitivity and 1-specificity. We recruited 101 patients with hand injury and 162 healthy participants. Results Correlation between all subtests of PPT and DASH-T were weak ( r = −0.282; −0.473: p<0.05). The cutoff value for the assembly subtest of PPT was 24.5. The range of area under the curve (AUC) values for PPT subtests was good to excellent (AUC: 0.82–0.92). Conclusion The current study demonstrates that PPT is a valid instrument for measuring hand dexterity in patients with hand injury. Results also suggest that PPT distinguished the patients with impaired hand function from those with unimpaired hand dexterity.