title: Beyond the traditional definition of breakthrough pain: an observational study.
abstract: BACKGROUND
  Breakthrough pain (BTP) is traditionally defined as a transitory pain flare in opioid-treated patients with chronic background pain. This definition has, however, been challenged in recent years. This study aimed to analyze BTP prevalence in different pain conditions.
  
  
  METHODS
  This was a prospective, non-interventional, observational study conducted from June to September 2011 in two Italian pain treatment reference centres. Consecutive patients aged >18 years with oncological or non-oncological pain were eligible for this study; background pain was acute/ subacute (<3 months) or chronic (>3 months). The characteristics of pain were evaluated by means of a structured interview by physicians, and patients were asked to complete a dedicated clinical study form. The following outcomes were assessed: chronic pain duration (in patients with chronic pain), BTP prevalence, and number and severity of daily BTP episodes. All outcomes were assessed in four populations of patients with: (a) chronic oncological pain; (b) chronic non-oncological pain; (c) non-chronic oncological pain; (d) non-chronic non-oncological pain. The correlation between BTP and gender was also investigated.
  
  
  RESULTS
  Of 1,270 patients with chronic pain, 1,086 had non-oncological pain (85.5%). Most patients (68.6%) with non-oncological pain were female (P = 0.001). Pain duration was significantly longer in non-oncological pain versus oncological pain groups (P = 0.002). BTP prevalence was lower in non-oncological patients (P < 0.001). No differences were reported in terms of number and severity of daily BTP episodes. BTP was more frequent in females with non-oncological pain (P = 0.04). Females had a significantly higher pain severity (P = 0.02) than males.
  
  
  CONCLUSIONS
  BTP is frequently reported in patients who do not have BTP according to the traditional definition. BTP frequency and severity is similar in oncological and non-oncological pain.
authors: Emergency Care, Critical Care Medicine, Pain Medicine and Anesthesiology Department, Tor Vergata Polyclinic, University of Rome Tor Vergata, Rome, Italy.
authors: Antonio
authors: A
authors: Gatti
authors: Marta
authors: M
authors: Gentili
authors: Vittorio
authors: V
authors: Iorno
authors: Massimo
authors: M
authors: Mammucari
authors: Giuseppe
authors: G
authors: Tufaro
authors: Marzia
authors: M
authors: Lazzari
authors: Alessandro Fabrizio
authors: AF
authors: Sabato
mesh_terms: D059390:Breakthrough Pain / Q000150:complications* / Q000453:epidemiology; D059350:Chronic Pain / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000150:complications; D010146:Pain / Q000150:complications; D011446:Prospective Studies; D012720:Severity of Illness Index