Episodic (breakthrough) pain prevalence in a population of cancer pain patients. Comparison of clinical diagnoses with the QUDEI--Italian questionnaire for intense episodic pain.

CONTEXT: Breakthrough/episodic pain (BP-EP) diagnosis is often based on clinical experience, and different opinions exist, even among palliative care clinicians, about its definition and application to clinical practice.
OBJECTIVES: The primary aim of this study was to assess the prevalence and clinical characteristics of BP-EP in an unselected Italian population of patients with cancer-related chronic pain, based on clinical diagnosis and on the use of an assessment tool, the Questionnaire for Intense Episodic Pain (QUDEI).
METHODS: A cross-sectional multicenter prevalence study of 240 consecutive cancer pain patients was carried out. The physicians participating in the study attended a training session aimed at defining and recognizing BP-EP. The QUDEI, a screening and assessment tool based on patient interview, diagnosed the presence of BP-EP in patients regularly taking analgesics for the previous three days and who had at least one pain flare in the previous 24 hours. Clinical evaluation and questionnaire application were carried out by different health care providers.
RESULTS: The estimated prevalence of BP-EP was 73% (95% confidence interval [CI] = 67%, 79%) when the diagnosis was made by physicians and 66% (95% CI = 60%, 72%) when the QUDEI was applied (86% agreement). When only patients with baseline pain less than or equal to six were included in the analysis, the above prevalences decreased to 67% and 60%, respectively.
CONCLUSION: Because BP-EP is a significant phenomenon in cancer pain management, its appropriate recognition requires a more widely, internationally accepted general definition and specific validated tools for its screening and evaluation.