How to assess the quality of information transfer from physician to patient? Choice of psychometric tests for a decision board in a French Regional Cancer Centre

Background: Decision boards are used to transfer information from physician s to patients to help them participate in the clinical decision-making proc ess. We present the tests and results of the psychometric properties of a d ecision board in a sample of healthy volunteers. Methods: In the Regional Cancer Centre located in Lyon, we developed a deci sion board for postmenopausal women with breast cancer after lumpectomy wit hout any poor prognostic factors. Two treatment options were proposed, one involving chemotherapy and the other not. We tested for the following psych ometric properties: comprehension, construct validity and reliability. Comp rehension was evaluated using a questionnaire, in order to test whether the rates of correct answers were due to chance alone. The construct validity was assessed by changing the information provided (relapse and survival rat es, characteristics of chemotherapy) and testing whether the proportion of healthy volunteers choosing an option changed in a predictable and signific ant way. The reliability was evaluated using the test-retest method. Two re liability statistics were computed: the Pearson correlation and the Intracl ass Correlation Coefficient. Results: In the sample of 40 healthy volunteers, 23 chose the option with c hemotherapy and 17 the option without chemotherapy. Results show that the d ecision board was comprehensive, valid (the women changed their choices in a predictable way) and reliable (Pearson correlation and Intraclass Correla tion Coefficient close to 1). Conclusion: The choice of the psychometrics properties tested and the stati stical tests used are discussed. The psychometric properties of our tool ar e found to be satisfactory.