The Edmonton staging system for cancer pain: preliminary report.

Fifty-six consecutive patients with pain due to cancer were admitted to a prospective study designed to test a clinical staging system for cancer pain. The system classifies patients in stage 1 (good prognosis) to stage 3 (poor prognosis) according to the mechanism of pain, characteristics of pain, previous narcotic exposure, cognitive function, psychological distress, tolerance and past history of drug addiction or alcoholism. During day 1 patients were staged after being seen by one of the investigators. Patients were treated for 21 days, when a final diagnosis of pain control was made. Eighteen of 22 patients in stage 1 achieved good pain control (82%) vs. 2/22 patients in stage 3 (10%; P less than 0.01). Sensitivity, specificity and negative predictive value of the system were 0.75, 0.86 and 0.80, respectively. We conclude that this is a simple and reliable system for clinical staging that can be used for clinical research and management of patients with cancer pain.