Validation of a newly developed questionnaire regarding clinical history in patients with breast and colorectal cancers

BACKGROUND: Understanding the close interaction between the specialties of cardiology and oncology is necessary for early detection of cardiovascular disease (CVD) events in cancer patients. For the risk assessment of CVD in Breast and Colorectal Cancers (CIBC) study, in the current study we aimed to validate a questionnaire for the assessment of clinical history in patients with breast cancer and colorectal cancer (CRC). METHODS: We determined the content validity of the questionnaire using the 2 indexes of content validity ratio (CVR) and content validity index (CVI) to examine the specificity, simplicity, clarity, and transparency of the items. Content validity assessment was performed through a panel of experts including 2 oncologists, 5 cardiologists, 2 general practitioners, and 1 epidemiologist. The reliability of the questionnaire was estimated using Cronbach's alpha coefficient in 50 patients. Intraclass correlation coefficient (ICC) was used to examine the reproducibility of the questionnaire during 1 week. RESULTS: The CRC and breast cancer questionnaire were designed with 16 and 32 questions, respectively. To obtain acceptable CVR, 5 and 11 questions were removed from the CRC and breast cancer questionnaires, respectively. Cronbach's alpha was 0.70 in the breast cancer questionnaire and 0.94 in the CRC questionnaire. All questions had a CVI of higher than 80%. The ICC in the breast cancer questionnaire ranged between 0.71 and 0.96 and in CRC questionnaire ranged between 0.78 and 0.98. CONCLUSION: The validity and reliability of our newly developed questionnaire was desirable. The reliability of the breast cancer questions was acceptable and that of the CRC questions was excellent. Thus, thus questionnaire can be used in this group of patients regardless of whether the goal is cardiac care or not.