title: A proposed taxonomy of terms to guide the clinical trial recruitment process.
abstract: BACKGROUND
  The successful conduct of clinical trials in palliative care is challenged by low accrual rates, high attrition of study patients during trials, difficulties managing comorbidity, and other factors. But what has been learned about improving the feasibility of palliative care research studies?
  
  
  OBJECTIVE
  To develop standard terms to describe patient accrual, and using these terms, describe an approach to allow investigators to predict trial feasibility.
  
  
  METHODS
  We proposed a standard language and definitions for specific elements of feasibility within clinical trial design and conduct. We then developed an approach to apply data generated from the use of these terms to allow researchers to predict feasibility at the design stage of a clinical trial's development.
  
  
  RESULTS
  We developed a taxonomy and then retrospectively applied the approach to four trials selected from our library of completed studies, to provide preliminary validity evidence. The approach includes a framework to help predict the number of patients needed to be assessed to achieve a study's accrual targets, as part of ongoing operational oversight to monitor the conduct and feasibility of a clinical trial.
  
  
  CONCLUSIONS
  Challenges to successful completion of palliative care trials are prevalent and serious. A taxonomy to characterize the eligible patient pool, and an approach by which feasibility is systematically investigated, hold the promise to enhance the effectiveness of scarce resources applied to palliative and end-of-life research.
authors.affiliation: Tom Baker Cancer Centre, Alberta Health Services, Calgary, Alberta, Canada. neilha@cancerboard.ab.ca
authors.forename: Neil A
authors.initials: NA
authors.lastname: Hagen
authors.forename: Jackson S
authors.initials: JS
authors.lastname: Wu
authors.forename: Carla R
authors.initials: CR
authors.lastname: Stiles
mesh_terms: D002986:Clinical Trials as Topic; D004777:Environment; D006801:Humans; D018579:Patient Selection; D010865:Pilot Projects; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012107:Research Design; D035842:Research Subjects / Q000145:classification*; D011795:Surveys and Questionnaires; D009626:Terminology as Topic