title: How are palliative care cancer populations characterized in randomized controlled trials? A literature review.
abstract: BACKGROUND
  The difficulties in defining a palliative care patient accentuate the need to provide stringent descriptions of the patient population in palliative care research.
  
  
  OBJECTIVE
  To conduct a systematic literature review with the aim of identifying which key variables have been used to describe adult palliative care cancer populations in randomized controlled trials (RCTs).
  
  
  METHODS
  The data sources used were MEDLINE (1950 to January 25, 2010) and Embase (1980 to January 25, 2010), limited to RCTs in adult cancer patients with incurable disease. Forty-three variables were systematically extracted from the eligible articles.
  
  
  RESULTS
  The review includes 336 articles reporting RCTs in palliative care cancer patients. Age (98%), gender (90%), cancer diagnosis (89%), performance status (45%), and survival (45%) were the most frequently reported variables. A large number of other variables were much less frequently reported.
  
  
  CONCLUSIONS
  A substantial variation exists in how palliative care cancer populations are described in RCTs. Few variables are consistently registered and reported. There is a clear need to standardize the reporting. The results from this work will serve as the basis for an international Delphi process with the aim of reaching consensus on a minimum set of descriptors to characterize a palliative care cancer population.
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Sunniva Centre for Palliative Care, Haraldsplass Deaconess Hospital, Bergen, Norway; Regional Centre of Excellence for Palliative Care, Western Norway, Haukeland University Hospital, Bergen, Norway. Electronic address: katrin.sigurdardottir@haraldsplass.no.
authors.forename: Katrin Ruth
authors.initials: KR
authors.lastname: Sigurdardottir
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Røros Rehabilitation Centre, Røros, Norway.
authors.forename: Line
authors.initials: L
authors.lastname: Oldervoll
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Regional Centre for Excellence in Palliative Care, South Eastern Norway, Oslo University Hospital, Oslo, Norway.
authors.forename: Marianne Jensen
authors.initials: MJ
authors.lastname: Hjermstad
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Oncology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Stein
authors.initials: S
authors.lastname: Kaasa
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Oncology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Anne Kari
authors.initials: AK
authors.lastname: Knudsen
authors.affiliation: Department of Oncology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Erik Torbjørn
authors.initials: ET
authors.lastname: Løhre
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; National Resource Centre for Late Effects After Cancer Treatment, Oslo University Hospital, Oslo, Norway.
authors.forename: Jon Håvard
authors.initials: JH
authors.lastname: Loge
authors.affiliation: European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Regional Centre of Excellence for Palliative Care, Western Norway, Haukeland University Hospital, Bergen, Norway.
authors.forename: Dagny Faksvåg
authors.initials: DF
authors.lastname: Haugen
mesh_terms: D006801:Humans; D009369:Neoplasms / Q000628:therapy*; D010166:Palliative Care; D016032:Randomized Controlled Trials as Topic / Q000379:methods*
keywords: Palliative care; basic data set; cancer; generalizability; literature review; patient characteristic; publication standard; randomized clinical trial