The Pain Descriptor System: Diagnostic specificity and predictive validity

Pain is a subjective, multidimensional experience influenced by several different factors. The measurement of pain can be used for diagnosis and evaluation of treatments. The McGill Pain Questionnaire (MPQ; Melzack, 1975) is the most widely used pain instrument; however, has several issues and is in a continued process of further refinement. One such attempt is the 36-word Pain Descriptor System (PDS; Fernandez, 2008) that overcomes some of the problems associated with the MPQ and offers practical utility in pain clinics. The current study aimed to test two hypotheses in a sample of 60 chronic pain patients: (1) the ability of the PDS scores to predicting disability as measured by the Pain Disability Questionnaire (PDQ; Anagnostis, Gatchel, & Mayer, 2004), and (2) the ability of the PDS to discriminating among three pain diagnoses -- musculoskeletal pain, arthritic pain, and neuropathic pain. The results indicated that negative affect is a significant predictor of psychosocial disability, and is even more crucial in contributing to disability than the physical sensation or the intensity of pain. The results also suggested that there is a unique constellation of words that discriminated the neuropathic pain group from the musculoskeletal and the arthritic pain group. These findings have important implications in the study of pain and disability. Further research using other samples of pain syndromes would provide additional information regarding the diagnostic utility of the PDS.