title: Practical problems with the collection and interpretation of serial quality of life assessments in patients with malignant glioma.
abstract: OBJECTIVE
  To assess the problems involved with the collection and interpretation of serial collected health related quality of life assessments in patients with malignant glioma.
  
  
  METHODS
  One-hundred and fifty nine patients with malignant glioma from three Scottish neurosurgical centres in whom assessments of performance status, neurological impairment, mood, and quality of life had been recorded over a 6-month period were prospectively identified. The amount of missing data and the reasons for missing data were assessed. Characteristics of patients that were fully compliant with serial assessments were then compared with those that were not.
  
  
  RESULTS
  Compliance with serial assessments (both patient and observer reported) was poor, dropping to less than 50% at 6 months. Observer reported measures showed a similar pattern of decline as patient reported measures. The largest single cause of missing data (approximately 70%) was due to administrative failure. Compliant patients were found to have a significantly greater probability of survival compared to non-compliant patients and were also found to be younger and fitter relative to the rest of the study population.
  
  
  CONCLUSIONS
  Studies utilising quality of life outcomes should give early consideration to minimising avoidable sources of missing data and recording the reasons for non-compliance. Quality of life studies basing conclusions on a complete case analysis should be wary of possible bias.
authors.affiliation: Edinburgh Centre for Neuro-Oncology, Western General Hospital, Edinburgh, Scotland, UK.
authors.forename: M
authors.initials: M
authors.lastname: Walker
authors.forename: J
authors.initials: J
authors.lastname: Brown
authors.forename: K
authors.initials: K
authors.lastname: Brown
authors.forename: A
authors.initials: A
authors.lastname: Gregor
authors.forename: I R
authors.initials: IR
authors.lastname: Whittle
authors.forename: R
authors.initials: R
authors.lastname: Grant
mesh_terms: D015982:Bias; D001932:Brain Neoplasms / Q000188:drug therapy / Q000523:psychology*; D003625:Data Collection / Q000379:methods; D005260:Female; D005910:Glioma / Q000188:drug therapy / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011446:Prospective Studies; D011788:Quality of Life; D012107:Research Design; D012606:Scotland; D011795:Surveys and Questionnaires; D015996:Survival Rate