Which variables are associated with pain intensity and treatment response in advanced cancer patients?--Implications for a future classification system for cancer pain

Eur J Pain. 2011 Mar;15(3):320-7. doi: 10.1016/j.ejpain.2010.08.001. Epub 2010 Sep 6.

Abstract

Background: This study is part of a research program to reach consensus on an international cancer pain classification system. A confirmative and explorative approach was applied to investigate which of the variables identified in the literature, by experts and patients that are associated with pain.

Methods: Data from an international, multicentre, cross-sectional study of cancer patients treated with opioids were investigated. Dependent variables were: average pain, worst pain, and pain relief (11-point Numerical Rating Scales). Forty-six independent variables were chosen based upon previous studies. Bivariate analyses identified independent variables associated with at least one of the dependent ones; 21 were included in multivariate linear regression analyses.

Results: Two thousand two hundred and seventy-eight patients were investigated; 52% males, mean age 62 years, mean Karnofsky Performance Status 59%, mean daily opioid oral equivalent dose 341 mg. Fifty-eight percent had breakthrough pain. Mean pain scores were: average pain 3.5, worst pain 5.3 and pain relief 74%. Variables most strongly associated with these three dependent variables were: breakthrough pain, psychological distress, sleep, and opioid dose.

Conclusions: Breakthrough pain and psychological distress were confirmed as key variables of a future classification system. Candidate variables were: sleep, opioid dose, pain mechanism, use of non-opioids, pain localisation, cancer diagnosis, location of metastases, and addiction.

Publication types

  • Consensus Development Conference
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Analgesia / methods
  • Analgesics, Opioid / therapeutic use
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / complications*
  • Neoplasms / therapy
  • Pain / classification*
  • Pain / diagnosis*
  • Pain / etiology
  • Pain Management
  • Pain Measurement / methods*
  • Quality of Life
  • Regression Analysis
  • Severity of Illness Index*
  • Stress, Psychological
  • Surveys and Questionnaires

Substances

  • Analgesics, Opioid