title: A cross-sectional study on prevalence of pain and breakthrough pain among an unselected group of outpatients in a tertiary cancer clinic.
abstract: OBJECTIVE
  Systematic knowledge about the prevalence and the treatment effects of cancer pain in patients attending a general oncology outpatient department is limited. The purpose of this study was to investigate the prevalence of pain in a large representative cohort of patients attending a general oncology outpatient department in order to guide further screening, classification, and treatment of pain.
  
  
  METHODS
  A cross-sectional study among patients visiting the outpatient clinic with histologically verified cancer, age≥18 years, adequate cognitive function, and no surgical procedures last 24 h were included. Pain was assessed by the Brief Pain Inventory and the Alberta Breakthrough Pain Assessment Tool.
  
  
  RESULTS
  Three hundred five patients were included. The mean age was 60 years, 94% had a WHO performance status of 0-1 and 59% received oncological treatment with a curative intent. The mean score for average pain last 24 h (numerical rating scale, 0-10) and current pain was 1.84 and 1.08, respectively. Twenty-two percent reported pain score of ≥4 as their average pain in the previous 24 h. Twenty-one percent reported breakthrough pain (BTP). In multivariate analyses, sleep, BTP, age, treatment intent, and comorbidity was significantly associated with mean average pain in the previous 24 h and explained 29% of the variability of average pain in the previous 24 h.
  
  
  CONCLUSIONS
  Of the patients at an oncology outpatient clinic, 22% reported clinically significant pain. These findings indicate that all patients are candidates to be screened for pain and, if present, a more detailed pain diagnosis should be established before any interventions can be recommended.
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway, sunil.raj@ntnu.no.
authors.forename: Sunil X
authors.initials: SX
authors.lastname: Raj
authors.forename: Morten
authors.initials: M
authors.lastname: Thronaes
authors.forename: Cinzia
authors.initials: C
authors.lastname: Brunelli
authors.forename: Marianne J
authors.initials: MJ
authors.lastname: Hjermstad
authors.forename: Pål
authors.initials: P
authors.lastname: Klepstad
authors.forename: Stein
authors.initials: S
authors.lastname: Kaasa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000554:Ambulatory Care Facilities; D059390:Breakthrough Pain / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000453:epidemiology*; D009664:Norway; D010045:Outpatients; D010147:Pain Measurement / Q000379:methods; D015995:Prevalence; D055815:Young Adult