title: Development, validation and psychometric properties of a diagnostic/prognostic tool for breakthrough pain in mixed chronic-pain patients.
abstract: OBJECTIVE
  Breakthrough pain (BTP) shows variable prevalence in different clinical contexts of cancer and non-cancer patients. BTP diagnostic tools with demonstrated reliability, validation and prognostic capability are lacking. We report the development, psychometric and validation properties of a diagnostic/prognostic tool, the IQ-BTP, for BTP recognition, its likelihood and clinical features among chronic-pain (CP) patients.
  
  
  METHODS
  n=120 consecutive mixed cancer/non-cancer CP in/outpatients. Development, psychometric analyses and formal validation included: Face/Content validity (by 'experts' opinion and assessing the relationship between the IQ-BTP classes and criteria derived from BTP operational-case-definition); Construct validity, by Principle Component Analysis (PCA); and the strength of Spearman correlation between IQ-BTP classes and the Brief Pain Inventory (BPI) items; Reliability, by Cronbach's alpha statistics. Associations with clinical/demographic moderators were assessed applying χ(2) analysis.
  
  
  RESULTS
  Potential-BTP was found in 36.7% of patients (38.4% of non-cancer and 32.4% of cancer patients). Among these the likelihood for BTP diagnosis was 'high' in 25%, 'intermediate' in 41% and, 'low' 34% of patients. Analyses showed significant differences between IQ-BTP classes and between the latter BPI pain-item scores. Correlation between IQ-BTP classes and BPI items was moderate. PCA and scree test identified 3 components accounting for 62.3% of the variance. Cronbach's alpha was 0.71.
  
  
  CONCLUSIONS
  The IQ-BTP showed satisfactory psychometric and validation properties. With adequate feasibility it enabled the allocating of cancer/non-cancer CP patients in three prognostic classes. Results are sufficient to warrant a subsequent impact study of the IQ-BTP as prognostic model and screening tool for BTP in both CP populations.
authors.affiliation: University of Bologna, Department of Medicine and Surgery Sciences, Via Massarenti n. 9, Bologna, 40138, Italy; Azienda Ospedaliera-Universitaria di Bologna Policlinico S. Orsola-Malpighi, Via Massarenti n. 9, Bologna, 40138, Italy; University of Bologna, Post Graduate School of Anaesthesia and Intensive Care, Via Massarenti n. 9, Bologna, 40138, Italy. Electronic address: boaz.samolskydekel@unibo.it.
authors.forename: Boaz Gedaliahu
authors.initials: BG
authors.lastname: Samolsky Dekel
authors.affiliation: University of Bologna, Post Graduate School of Anaesthesia and Intensive Care, Via Massarenti n. 9, Bologna, 40138, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Remondini
authors.affiliation: University of Bologna, Post Graduate School of Anaesthesia and Intensive Care, Via Massarenti n. 9, Bologna, 40138, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Gori
authors.affiliation: University of Bologna, Post Graduate School of Anaesthesia and Intensive Care, Via Massarenti n. 9, Bologna, 40138, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Vasarri
authors.affiliation: University of Bologna, Department of Medicine and Surgery Sciences, Via Massarenti n. 9, Bologna, 40138, Italy; Azienda Ospedaliera-Universitaria di Bologna Policlinico S. Orsola-Malpighi, Via Massarenti n. 9, Bologna, 40138, Italy; University of Bologna, Post Graduate School of Anaesthesia and Intensive Care, Via Massarenti n. 9, Bologna, 40138, Italy.
authors.forename: GianFranco
authors.initials: G
authors.lastname: Di Nino
authors.affiliation: University of Bologna, Department of Medicine and Surgery Sciences, Via Massarenti n. 9, Bologna, 40138, Italy; Azienda Ospedaliera-Universitaria di Bologna Policlinico S. Orsola-Malpighi, Via Massarenti n. 9, Bologna, 40138, Italy; University of Bologna, Post Graduate School of Anaesthesia and Intensive Care, Via Massarenti n. 9, Bologna, 40138, Italy.
authors.forename: Rita Maria
authors.initials: RM
authors.lastname: Melotti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059390:Breakthrough Pain / Q000175:diagnosis* / Q000453:epidemiology*; D059350:Chronic Pain / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods* / Q000592:standards*; D025341:Principal Component Analysis / Q000379:methods; D011379:Prognosis; D011446:Prospective Studies; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult
keywords: Breakthrough pain; Cancer pain; Chronic pain; Construct validity; Content validity; Factorial validity: Prognosis; Internal consistency; Psychometric validation