Validation study of the EORTC information questionnaire (EORTC QLQ-INFO25) in Iranian cancer patients.

INTRODUCTION

Developing a tool for measuring patient's needs is a vital step in the process of cancer treatment and research. In recent years, the European Organization for Research and Treatment of Cancer (EORTC) made a questionnaire to measure cancer patients' received information. Since validity and reliability of any instrument should be evaluated in the new environment and culture, the aim of this study was to assess the validity and reliability of the EORTC QLQ-INFO25 in Iranian cancer patients.

MATERIALS AND METHODS

One hundred seventy-three patients with different stages of cancer filled questionnaire EORTC QLQ-INFO25, EORTC QLQ-C30, and EORTC IN-PATSAT32. Twenty-five patients answered the questionnaire twice at an interval of 2 weeks. Reliability and validity of the questionnaire was measured by Cronbach's alpha, interclass correlation, test retest, inter-rater agreement (IRA), and exploratory factorial analyses.

RESULTS

Using a conservative approach, the IRA for the overall relevancy and clarity of the tool was 87/86% and 83.33%, respectively. Overall appropriateness and clarity were 94.13 and 91.87%, respectively. Overall integrity of the instrument was determined to be 85%. Cronbach's alpha coefficients for all domains and total inventory were top 70 and 90%, respectively. Interclass correlation index ranges between 0.708 and 0.965. Exploratory factorial analyses demonstrate six fields suitable for instrument. Correlation between areas of the questionnaires EORTC QLQ-INFO25 and EORTC in-Patsat32 represents the convergent validity of the questionnaire. Also, results show a standard divergent validity in all domains of the questionnaire (Rho <0.3). Low correlation between the areas of the questionnaires EORTC QLQ-INFO25 and EORTC QLQ-C30 (<0.3) demonstrates the divergence validity of the questionnaire.

CONCLUSION

The results showed that Persian version of the questionnaire EORTC QLQ-INFO25 is a reliable and valid instrument for measuring the perception of information in cancer patients.