A systematic review on barriers hindering adequate cancer pain management and interventions to reduce them: A critical appraisal

Abstract

The aim of this paper is to identify the major barriers hindering adequate pain management and critically review interventions aiming to overcome them. We searched relevant literature on PubMed published between January 1986 and April 2007. The most frequently mentioned barriers for both patients and professionals were knowledge deficits, inadequate pain assessment and misconceptions regarding pain. Four interventions were identified: patient education, professional education, pain assessment and pain consultation. These interventions were never combined in multidisciplinary study protocols. Most RCTs included small groups of patients and reported no power analysis. Studies on professional education and pain assessment did not evaluate patients’ outcomes. In 5 of 11 RCTs on patient education, pain intensity decreased statistically significantly. In two RCTs on pain consultation, patients’ pain decreased statistically significantly, although the adequacy of pain treatment did not change. In conclusion, international guidelines on multidisciplinary interventions in pain management are partly substantiated by clinical trials.

Introduction

Pain is one of the most frequent and distressing symptoms in cancer. Pain is present in 36–61% of patients depending on cancer type, stage of disease and patient setting, e.g. in- or outpatients.1, 2, 3 Of patients with advanced cancer 64% experience pain.⁴ Management of cancer pain is considered to be complex. In 1986, the World Health Organisation (WHO) published the analgesic ladder.⁵ The WHO analgesic ladder categorises analgesics into three steps that, depending on the pain intensity, progress from non-opioid analgesics to weak opioids and then to strong opioids. Analgesics should be prescribed ‘around-the-clock’ (ATC) for continuous pain and ‘as needed’ (PRN) for breakthrough pain.⁵ The WHO analgesic ladder has been generally accepted as the foundation of cancer pain treatment. The fact remains, however, that despite the existing guidelines and knowledge about pain and pain management, cancer pain relief is still inadequate.⁶

Cleeland et al. developed the ‘Pain Management Index’ (PMI), a tool to assess the congruence between severity of pain and medication prescribed.⁷ The PMI relates the patients’ worst pain intensity (categorised as none, mild, moderate or severe) to the most potent analgesic prescribed (no analgesics; non-opioid analgesics; weak opioids; strong opioids). It is calculated by subtracting the worst pain from the most potent analgesic prescribed. Negative PMI scores are considered to indicate suboptimal medication prescription and scores of zero or greater are considered indicating acceptable analgesic potency.⁷ According to the PMI, 43% of patients, outpatients as well as inpatients, are treated inadequately.⁸

However, although almost half of the patients are treated inadequatly,⁸ it has been proposed that effective treatment of pain should be feasible for 70–90% of oncology patients.⁶ Numerous barriers have been documented that prevent patients from receiving effective pain treatment and avert physicians from providing adequate pain management. The first aim of this paper is to identify the major barriers hindering adequate pain management, patient – related barriers as well as professional – related barriers. The second aim is to critically review RCTs on interventions aiming to overcome these barriers with respect to the methodological quality of these studies and the effect on clinically relevant outcome measurements.