Objective: This paper reports on the development of the Skin Picking Scale (SPS), a six-item paper-and-pencil measure for the assessment of skin picking.
Methods: 28 severe self-injurious and 77 non-self-injurious skin pickers initially completed an eight-item severity scale modeled after the Yale--Brown Obsessive--Compulsive Scale (Y-BOCS).
Results: Group comparisons and part--whole correlations for individual scale items resulted in a six-item scale with a total score range of 0--24. A Cronbach's alpha coefficient of.80 indicated moderate internal consistency for the scale. Construct validity was demonstrated by significant correlations between SPS total scale scores and self-reported average duration of skin picking episodes. Significant correlations were also reported between SPS total scale scores and both Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) scores, as well as self-reported intensity of emotions during the picking process. Lastly, sensitivity and specificity analyses suggest that a SPS cut-off score of 7 differentiates severe self-injurious and non-self-injurious skin pickers.
Conclusion: The SPS is a valid and reliable self-report scale for the assessment of severity in medical and psychiatric patients who endorse skin picking.