title: How far along the disease trajectory? An examination of the time-related patient characteristics in the palliative oncology literature.
abstract: Adequate reporting of time-related patient characteristics is needed for research findings to be properly interpreted, applied, and reproduced. Our objective was to characterize the time-related patient characteristics in palliative oncology studies and to examine the differences in time-related patient characteristics by various study characteristics.
  
  
  
  We extracted time-related patient characteristics including actual survival, performance status, cancer stage, disease trajectory, study setting, and eligibility criteria (life expectancy and performance status) from an established cohort of original palliative oncology articles published in 2004 and 2009.
  
  
  
  Among 742 original articles, 409 (55 %) were case series. Only 247 (33 %) articles reported actual survival, 157 (21 %) reported actual performance status, 362 (49 %) cancer stage, and 392 (53 %) reported study setting. Based on all the available time-related characteristics, we were able to classify the studies into specific time-related categories in 378 (51 %) studies. Among these, only 47 (13 %) focused on patients in the last month of life. Compared to studies involving patients earlier in the disease trajectory, these studies were more likely to be case series (81 vs. 56 %, P = 0.005), retrospective (64 vs. 49 %, P = 0.03), and had a smaller sample size (median 20 vs. 61, P = 0.06).
  
  
  
  A majority of studies did not adequately report time-related patient characteristics. We also identified a gap in both the quantity and quality of studies involving patients in the last month of life. Our study has implications for study reporting and future directions for palliative oncology research.
authors.affiliation: Department of Palliative Care and Rehabilitation Medicine Unit 1414, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA.|Siriraj Palliative Care Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Supakarn
authors.initials: S
authors.lastname: Tayjasanant
authors.affiliation: Department of Palliative Care and Rehabilitation Medicine Unit 1414, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bruera
authors.affiliation: Department of Palliative Care and Rehabilitation Medicine Unit 1414, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA. dhui@mdanderson.org.
authors.forename: David
authors.initials: D
authors.lastname: Hui
mesh_terms: D016022:Case-Control Studies; D006801:Humans; D008495:Medical Oncology / Q000379:methods; D009369:Neoplasms / Q000473:pathology* / Q000628:therapy*; D010166:Palliative Care / Q000379:methods*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D012189:Retrospective Studies
keywords: Palliative care; Patient characteristics; Performance status; Reporting; Research; Survival