Background: For pertinent investigation of patient satisfaction it is important to know what type of data collection procedure yields optimal results. In this study, we compared a self- versus interview administration of the European Organisation for Research and Treatment of Cancer (EORTC) patient satisfaction questionnaire (QLQ-SAT32), noting response and item omission rates. We also assessed the correlation and agreement between responses according to these modalities of questionnaire administration.
Methods: 123 patients recruited in two anti-cancer Centers in France were asked to complete the QLQ-SAT32 at home within 2 weeks of hospital discharge and were randomly allocated to participate in a telephone interview-administration of the QLQ-SAT32, either before or after self-completing the QLQ-SAT32.
Results: 104 patients completed both modalities of questionnaire administration. Agreement proved excellent for the doctors' and nurses' subscales and satisfactory for the services' subscale and the general satisfaction single item. However, a significant difference in response rate showed up between Centers (different interviewers) and the interview modality revealed an item omission rate higher than for the self-administration modality.
Conclusion: Self- and interview-administration of the QLQ-SAT32 provided similar responses however different response rate between interviewers and higher item omission rate in interviews suggests a biasing effect of that modality of data collection.