title: Assessment of quality of life in patients with angina pectoris: Progress made by the Dutch Mononitrate Quality-Of-Life (DUMQOL) Study Group.
abstract: BACKGROUND
  Two major issues in quality of life (QOL) research are the patient's opinion as a contributing factor in QOL assessments, and the lack of sensitivity of QOL assessments.
  
  
  OBJECTIVE
  To review results from recent research by the Dutch Mononitrate Quality Of Life (DUMQOL) Study Group relevant to these two issues.
  
  
  METHODS
  Using a test battery including Stewart's Short Form (SF)-36 Questionnaire and the DUMQOL-50 questionnaire, the DUMQOL Study Group tested the hypothesis that the patient's opinion might be an independent determinant of QOL. To do this, a stepwise multiple regression analysis of data from 82 patients attending an outpatient clinic with stable angina pectoris was performed. Secondly, using an odds ratio approach to QOL scores in 1350 outpatients with stable angina pectoris who were attending a clinic, the DUMQOL Study Group assessed the question whether relative scores might provide increased precision in estimating the effects of patient characteristics on QOL data.
  
  
  RESULTS
  Psychological distress was the most important contributor to QOL (beta 0.43, p<0.0001). Also, the patient's opinion on his/her QOL significantly contributed to QOL (beta 0.22, p=0.032). Physical health status according to the patient's judgement only made a borderline contribution (beta 0.19, p=0.71), while the physician's judgement was not associated with QOL at all (beta 0.11, p=0.87). Regarding the second issue, increased QOL difficulties were observed in New York Heart Association (NYHA) angina class III-IV patients, in patients with comorbidity, as well as in female and elderly patients. Odds ratios can be used in these categories to predict the benefit from treatments.
  
  
  CONCLUSIONS
  Recent QOL research of the DUMQOL Study Group allows conclusions to be drawn that are relevant to clinical practice. QOL should be defined in a subjective rather than an objective method. The patient's opinion is an important independent contributor to QOL. The comparison of absolute QOL scores lacks the sensitivity to truly estimate QOL. The odds ratio approach of QOL scores provides increased precision in estimating QOL.
authors.forename: T J
authors.initials: TJ
authors.lastname: Cleophas
authors.forename: M G
authors.initials: MG
authors.lastname: Niemeyer
authors.forename: A H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: B
authors.initials: B
authors.lastname: Buunk
authors.forename: E E
authors.initials: EE
authors.lastname: van der Wall
keywords: QOL; QOL assessments; angina pectoris; odds ratios; quality of life