title: Unsolved problems in evaluating the quality of life of cancer patients.
abstract: BACKGROUND
  The current means of evaluating the quality of life (QoL) of cancer patients, generally employ a multidimensional approach involving validated self-administered questionnaires. In measuring QoL, as well as in interpreting the results of an assessment, the patient, questionnaire, and setting of administration may all give rise to problems.
  
  
  METHODS
  Based on our experience and review of a large number of published papers, the most relevant problems in evaluating QoL of cancer patients are highlighted.
  
  
  RESULTS
  The difficulties that patients have with the most frequently used psychometric questionnaires are demonstrated by the fact that more than 10% of patients who gave their consent to be enrolled in a longitudinal study measuring QoL did not fill out the first questionnaire. This percentage is higher among older patients having a low level of education. in patients with disseminated disease, and among those with a low performance status. Moreover, in longitudinal studies, there is a very high incidence of drop-outs, often correlated with the progression of disease, so that the results are sometimes inconsistent.
  
  
  CONCLUSIONS
  Quality of life, depending not only on the type and stage of disease, and the administered treatment, but also on patient characteristics, should be assessed only in a randomised clinical trial. In any case, the most relevant problem is connected to the selection bias due to drop-outs. Reasons for this should be sought in the apparent complexity of the questionnaire and inadequate information given to the patient. Simpler instruments, which can be filled out in a shorter period of time, and specific training by research nurses could help minimize this excessive phenomenon.
authors.affiliation: Department of Internal Medicine and Public Health, University of L'Aquila, Italy. ballatori@sscaql.cc.univaq.it
authors.forename: E
authors.initials: E
authors.lastname: Ballatori
mesh_terms: D006801:Humans; D009369:Neoplasms / Q000523:psychology*; D010352:Patient Dropouts; D011594:Psychometrics; D011788:Quality of Life; D012647:Self-Assessment; D011795:Surveys and Questionnaires