Adequacy of cancer-related pain management and predictors of undertreatment at referral to a pain clinic

Background: Several guidelines have advocated the need for adequate cancer-related pain (CRP) management. The pain management index (PMI) has been proposed as an auditable measure of the appropriateness for analgesic therapy. Objectives: To determine the adequacy of CRP management based on the PMI status and its patient-related predictors at the point of referral to a pain clinic (PC). Methods: Consecutive patients referred to a PC had standardized initial assessments and status documentation on the Brief Pain Inventory (BPI) ratings; pain mechanism, using a neuropathic pain diagnostic questionnaire (the Douleur Neuropathique 4 tool); episodic pain; oral morphine equivalent daily dose; the Hospital Anxiety Depression Scale and the Emotion Thermometer scores; and cancer diagnosis, metastases, treatment, and pain duration. Predictors of "negative PMI status" [PMI(-)] were examined in logistic regression models. Variables with p < 0.25 in an initial bivariable analysis were entered into a multivariable model. Results: Of 371 participants, 95 (25.6%) had PMI(-), suggesting undertreatment of CRP. Both female sex and higher scores on the BPI's "interference with general activity" more strongly predicted PMI(-). Patients who received either radiotherapy or one or more adjuvant analgesics prior to the initial consultation at the PC, those who had neuropathic pain, those who had a greater need for emotional help, and those with higher BPI's "relief" scores were all less likely to be PMI(-). Conclusion: The potential burden of patient and family distress associated with suboptimal CRP management in one in four patients should generate major public health concern and prompt appropriate educational and health policy measures to address the deficit.