The relationship of pain characteristics, type of cancer, and opioid consumption to quality of life, psychological distress, and pain outcomes

Abstract

The relationship of pain to quality of life (QOL) outcomes has been studied; yet, for the most part, the presence and magnitude of pain have been the major variables of interest. Little is known about the impact of pain types (somatic, visceral and neuropathic) on QOL. The primary purpose of this study was to evaluate the extent to which physiological source(s) of pain, pain duration, intensity, location(s), number of sites, relief, sensory and affective components, and opioid consumption affect perceptions of QOL and psychological distress. In addition, the association and validity of pain language in predicting physiologic pain were evaluated. A convenience sample (N = 100) of subjects with chronic pain from advanced cancer was recruited for study from three outpatient medical oncology practices. Information was collected on age, sex, tumor type, treatment information, average daily opioid requirement, physiologic source(s) of pain, pain location(s), number of painful sites, and duration of pain. Each subject completed the following measures: (a) a Numeric Pain Rating (NRS) Scale for present pain intensity (PPI) and average worst pain intensity (WPI); (b) pain relief scale (VASPR); (c) the sensory and affective Short Form-McGill Pain Questionnaire (SF-MPQ); (d) The Brief Symptom Inventory (BSI) (psychological distress); and, (e) The Quality of Life Survey (QOLS). Data analyses were conducted using The SSPS-PC Program and the SAS Software System. Multiple regression analysis determined that SF-MPQ affective component, VASPR and age accounted for a significant portion (25.3%) of the variance in the QOLS scores, while WPI, VASPR and age explained 21.3% of the model for psychological distress. Discriminant Analysis, Chi-Square analyses and linear logistic regression evaluated significant associations of pain language to physiological pain categories. No significant differences in the QOLS, BSI and average pain intensity were found for pain location and cancer diagnosis using MANOVA's. ANOVA and Student's t-tests assessed differences among pain types. Subjects with a component of neuropathic pain experienced significantly more psychological distress, (p<.05), average pain (p<.01), greater sensory and affective pain (SF-MPQ) (p<.001), and present pain (p<.01).