How does pain experience relate to the need for pain relief? A secondary exploratory analysis in a large sample of cancer patients

Purpose: To explore (1) the information obtained from related but conceptually different approaches to pain assessment and (2) the extent to which the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) can be used as a screening tool to predict patient-reported need for pain relief. Methods: Cancer patients randomly sampled from 56 hospital departments were included. Questionnaire items assessed patients’ (a) pain experience using the EORTC QLQ-C30 pain scale and its two pain items separately (pain intensity and pain interference) and (b) pain burden and (c) need for pain relief using the Three-Levels-of-Needs Questionnaire (3LNQ). Results: Of the 2364 patients contacted by mail, 1447 (61 %) completed the questionnaires. Among these, 51 % reported at least “a little” pain on the pain intensity item. The number of patients reporting pain to be a burden was similar, and pain experience and pain burden were highly correlated (correlation coefficients ranged from 0.85 to 0.91). Pain experience and pain burden were moderately correlated with the need for pain relief. A receiver-operating characteristic (ROC) curve analysis showed that the EORTC QLQ-C30 discriminated between patients with and without a need for pain relief to an acceptable degree (area under the curve (AUC) 0.73–0.77). The cut-point a little gave a sensitivity of 84 % and specificity of 59 % for the item “Have you had pain?” and a sensitivity of 72 % and a specificity of 72 % for the pain scale. Conclusions: The majority of patients who experienced pain felt it to be a problem. Pain experience and pain burden were substantially related to need for pain relief, and the latter could be predicted from the EORTC QLQ-C30.