title: Clinical trials in palliative care: a systematic review of their methodological characteristics and of the quality of their reporting.
abstract: BACKGROUND
  Over the past decades there has been a significant increase in the number of published clinical trials in palliative care. However, empirical evidence suggests that there are methodological problems in the design and conduct of studies, which raises questions about the validity and generalisability of the results and of the strength of the available evidence. We sought to evaluate the methodological characteristics and assess the quality of reporting of clinical trials in palliative care.
  
  
  METHODS
  We performed a systematic review of published clinical trials assessing therapeutic interventions in palliative care. Trials were identified using MEDLINE (from its inception to February 2015). We assessed methodological characteristics and describe the quality of reporting using the Cochrane Risk of Bias tool.
  
  
  RESULTS
  We retrieved 107 studies. The most common medical field studied was oncology, and 43.9% of trials evaluated pharmacological interventions. Symptom control and physical dimensions (e.g. intervention on pain, breathlessness, nausea) were the palliative care-specific issues most studied. We found under-reporting of key information in particular on random sequence generation, allocation concealment, and blinding.
  
  
  CONCLUSIONS
  While the number of clinical trials in palliative care has increased over time, methodological quality remains suboptimal. This compromises the quality of studies. Therefore, a greater effort is needed to enable the appropriate performance of future studies and increase the robustness of evidence-based medicine in this important field.
authors.affiliation: Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Bouça-Machado
authors.affiliation: Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal.
authors.forename: Madalena
authors.initials: M
authors.lastname: Rosário
authors.affiliation: Center for Evidence-Based Medicine, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Alarcão
authors.affiliation: Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal.
authors.forename: Leonor
authors.initials: L
authors.lastname: Correia-Guedes
authors.affiliation: Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal.
authors.forename: Daisy
authors.initials: D
authors.lastname: Abreu
authors.affiliation: Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal. joaquimjferreira@gmail.com.|Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Medicine, University of Lisbon, Avenue Professor Egas Moniz, 1649-028, Lisbon, Portugal. joaquimjferreira@gmail.com.
authors.forename: Joaquim J
authors.initials: JJ
authors.lastname: Ferreira
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D000068598:Data Accuracy; D006801:Humans; D008511:Medicine / Q000706:statistics & numerical data; D010043:Outcome and Process Assessment, Health Care; D010166:Palliative Care / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D012107:Research Design / Q000592:standards; D018401:Sample Size; D011795:Surveys and Questionnaires
keywords: Clinical trials; Methodological quality; Palliative care; Risk of bias