Patient-rated questionnaires are increasingly used to assess health-related quality of life.
We studied one aspect of the validity of such measures that has rarely been investigated : do patients interpret questionnaires in the same way as do the researchers reporting the results ?
If not, there may be a problem.
We employed the EORTC QLQ-C30 quality-of-life questionnaire to study 95 cancer patients and measured the agreement between (1) the patient's self-assessment and (2) an observer's rating of the patient's open-ended responses to the same questionnaire administered as an interview.
The observer made qualitative recordings describing potential misinterpretations.
The agreement between patients'and observers'ratings was high (median kappa=0.85, range 0.49-1.00).
The qualitative data revealed a few minor validity problems.
One of these, selective reporting, may lead to systematic errors : some patients reported only what they considered « relevant » symptoms.
The combination of quantitative and qualitative methods proved useful for questionnaire validation.
Mots-clés Pascal : Questionnaire, Qualité vie, Santé, Homme, Tumeur maligne, Validation test, Autoévaluation, Malade, Accord interjuge, Psychométrie, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30
Mots-clés Pascal anglais : Questionnaire, Quality of life, Health, Human, Malignant tumor, Test validation, Self evaluation, Patient, Interrater agreement, Psychometrics
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0323753
Code Inist : 002B30A11. Création : 12/09/1997.