title: Understanding quality of life in patients with colorectal cancer: comparison of data from a randomised controlled trial, a population based cohort study and the norm reference population.
abstract: OBJECTIVE
  Quality of life (QoL) is an important outcome measure in clinical studies. However, there is little experience with the interpretation of QoL results.
  
  
  METHODS
  To guide interpretation of QoL results from a randomised controlled trial (RCT) targeting the effectiveness of the immune modulator G-CSF on postoperative recovery in high risk (ASA III/IV) colorectal cancer patients, we compared RCT data with data from a population based cohort study and norm reference data. QoL was assessed using the European Organisation for the Research and Treatment of Cancer (EORTC) QLQ-C30 and CR38 questionnaires. QoL results were analysed on discharge from hospital and six months postoperatively.
  
  
  RESULTS
  Colorectal cancer patients (both from the RCT and the cohort study) showed the greatest differences in QoL scores compared to norm reference data at discharge from hospital. Six months postoperatively, global quality of life and pain approximated norm reference values indicating optimal recovery. However, deficits still appeared in scores for role functioning, physical functioning, social functioning and fatigue. The best improvements (discharge from hospital to six months postoperatively) were seen with respect to physical functioning, fatigue and pain.
  
  
  CONCLUSIONS
  For further analysis of RCT data, physical functioning and fatigue scores may be more sensitive than global quality of life to detect differences in treatment effects.
authors.affiliation: Association of the Scientific Medical Societies in Germany (AWMF), c/o Institute of Theoretical Surgery, Philipps-University Marburg, Marburg, Germany. kopp@mailer.uni-marburg.de
authors.forename: I
authors.initials: I
authors.lastname: Kopp
authors.forename: A
authors.initials: A
authors.lastname: Bauhofer
authors.forename: M
authors.initials: M
authors.lastname: Koller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D005221:Fatigue / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012016:Reference Values; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome