Prospective evaluation of perceived barriers to medication adherence by patients on oral antineoplastics.

Abstract

6042 Background: Appropriate use of oral antineoplastics (OA), especially those with a food-effect, is a challenge for patients and clinicians. Patient adherence is essential to optimize outcomes, minimize toxicity, minimize bias in clinical trials, and reduce health care costs. As the use of OA grows, due to the narrow therapeutic margin, it is critical to understand the barriers to patient adherence. The purpose of this study was to analyze cancer patients’ use of OAs and identify opportunities to improve patient adherence. Methods: We developed and tested a 30-question survey to address frequency and reasons for reducing/skipping doses; sources of information for OA use; perceived importance of food-drug effects, and ease of understanding directions on vial label. Surveys, consisting of Likert scale and multiple choice questions, were distributed to adult cancer patients on OAs at the UNC Cancer Hospital clinics. Results: Seventy-seven patients taking OAs with CML, RCC, breast cancer, and GI tumors completed the survey with a response rate of 97%. This was a well-educated population with 71% having completed some college; 54% female and 58% older than 50 years. Forty-three percent of patients taking drugs with a significant food-drug effect (sorafenib, pazopanib, lapatinib, imatinib, nilotinib, and capecitabine) did not think about the last time they ate before taking their OA and 23% did not know that their OA had a food-drug effect. In addition, 21% of patients indicated they intentionally skipped/cut back on their OAs and 38% of those did not inform their physician. Although 97% reported no difficulty reading instructions on drug vial, nearly 20% had some difficulty understanding the directions. Conclusions: There are three main barriers associated with appropriate use of OAs: confusion or misunderstanding about the timing of drug with food; reducing/stopping drug without informing MD; and difficulty understanding directions on the drug vial label. A multipronged integrated approach involving the pharmacist, physician and nurse is needed to optimize communication of directions for optimal OA use.