Validity and Reliability of a Survey Questionnaire Assessing Pharmacists' Knowledge, Attitudes, and Practices About Potential Drug Interactions Among Cancer Patients

Background: Cancer patients often undergo complicated treatment plans that involve numerous medications throughout therapy. Pharmacists’ knowledge about the potential drug interactions in cancer patients and their practices is essential to reduce avoidable drug-related problems and increase the efficacy and compliance of chemotherapy. A validated knowledge, attitudes, and practices (KAP) questionnaire regarding pharmacists’ knowledge, attitudes, and practices related to potential drug interactions among cancer patients isn’t available. Objectives: The purpose of this study was to develop a reliable and valid questionnaire to assess pharmacists’ knowledge of possible medication interactions with cancer patients. Materials and Methods: This cross-sectional study was conducted among pharmacists working in oncology departments in the Babylon Governorate. After 100 individuals finished the questionnaire, 50 of them retook it two weeks later. Using Cronbach’s α and interclass correlation coefficients, respectively, internal and test-retest reliability were evaluated. Exploratory factor analysis was used to evaluate construct validity. Results: The questionnaire was completed by 100 individuals, with a mean age of 28.32 ± 2.59 years, and 77% of them were female. The Knowledge, Attitude, and Practice parts, and the overall questionnaire, have Cronbach’s α values of 0.719, 0.782, 0.803, and 0.795, respectively. According to the interclass correlation coefficient, the test-retest reliability results for knowledge, attitudes, and practices were 0.816, 0.783, and 0.839, respectively. Seven factors involving (30) items were obtained in the exploratory factor analysis, with a cumulative initial eigenvalue contribution rate of 71.39%. Conclusion: The questionnaire’s criteria for assessing pharmacists’ knowledge of possible medication interactions with cancer patients were effective.