A review of factors influencing non-adherence to oral antineoplastic drugs

Purpose Adherence to oral antineoplastic drugs is a complex phenomenon, and knowledge about the reasons that people with cancer do not adhere to their prescriptions is essential to inform adherence-related support in clinical and research contexts. This study aims to provide an up-to-date summary of the key reasons for non-adherence to oral antineoplatic drugs (OAD) in people with cancer. Methods Electronic databases Medline, Embase, Emcare, and PsychINFO were searched for systematic reviews and studies published between January 2010 and March 2018. Data was analyzed and extracted by two independent reviewers. Results Three systematic reviews and two studies were included in the review. Key factors for non-adherence were classified as either modifiable or non-modifiable factors. Side effects, forgetfulness, and poor knowledge about OAD were identified as modifiable factors while co-payment, age, regimen complexity. and time since diagnosis were identified as non-modifiable factors. Most of the included studies focused on breast cancer and chronic myeloid leukemia (CML) patients. Low methodological quality and different adherence cut-off rates were observed in the included literature. Conclusions More research with rigorous methodology and diverse cancer types is needed to increase evidence on the reasons for OAD non-adherence. However, findings from this study may serve to aid in drafting guidelines and suitable interventions for adherence-related support to OAD users.