title: How are patient populations characterized in studies investigating depression in advanced cancer? Results from a systematic literature review.
abstract: BACKGROUND
  Prevalence rates of depression in patients with advanced cancer vary considerably. This may be because of heterogeneous samples and use of different assessment methods. Adequate sample descriptions and consistent use of measures are needed to be able to generalize research findings and apply them to clinical practice.
  
  
  OBJECTIVE
  Our objective was twofold: First, to investigate which clinically important variables were used to describe the samples in studies of depression in patients with advanced cancer; and second, to examine the methods used for assessing and classifying depression in these studies.
  
  
  METHODS
  PubMed, PsycINFO, Embase, and CINAHL were searched combining search term groups representing "depression," "palliative care," and "advanced cancer" covering 2007-2011. Titles and abstracts were screened, and relevant full-text articles were evaluated independently by two authors. Information on 32 predefined variables on cancer disease, treatment, sociodemographics, depression-related factors, and assessment methods was extracted from the articles.
  
  
  RESULTS
  After removing duplicates, 916 citations were screened of which 59 articles were retained. Age, gender, and stage of the cancer disease were the most frequently reported variables. Depression-related variables were rarely reported, for example, antidepressant use (17%) and previous depressive episodes (12%). Only 25% of the studies assessed and classified depression according to a validated diagnostic system.
  
  
  CONCLUSIONS
  Current practice for describing sample characteristics and assessing depression varies greatly between studies. A more standardized practice is recommended to enhance the generalizability and utility of findings. Stakeholders are encouraged to work toward a common standard for sample descriptions.
authors.affiliation: European Palliative Care Research Centre (PRC), 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. Electronic address: elene.janberidze@ntnu.no.
authors.forename: Elene
authors.initials: E
authors.lastname: Janberidze
authors.affiliation: European Palliative Care Research Centre (PRC), 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 (PRC), 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
authors.affiliation: European Palliative Care Research Centre (PRC), 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; Sunniva Centre for Palliative Care, Haraldsplass Deaconess Hospital, Bergen, Norway.
authors.forename: Katrin Ruth
authors.initials: KR
authors.lastname: Sigurdardottir
authors.affiliation: European Palliative Care Research Centre (PRC), 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: Erik Torbjørn
authors.initials: ET
authors.lastname: Løhre
authors.affiliation: Department of Behavioural Sciences in Medicine, Institute of Basic Medical Science, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Hanne Cathrine
authors.initials: HC
authors.lastname: Lie
authors.affiliation: Department of Behavioural Sciences in Medicine, Institute of Basic Medical Science, Faculty of Medicine, University of Oslo, Oslo, 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 (PRC), 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 (PRC), 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
mesh_terms: D017677:Age Distribution; D015982:Bias; D015984:Causality; D015897:Comorbidity; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D009369:Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D010166:Palliative Care / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D063189:Symptom Assessment / Q000379:methods* / Q000706:statistics & numerical data*
keywords: Advanced cancer; assessment; depression; generalizability; palliative care