Medication adherence to oral anticancer drugs: systematic review

Abstract

Many studies have demonstrated that non-adherence to oral anticancer drugs (OACDs) has challenged treatment efficacy. Otherwise, few validated tools exist to measure patients' adherence to medication regimen in clinical practice. To synthesize previous studies on adherence by cancer patients taking OACDs, especially in targeted therapy, a systematic search of several electronic databases was conducted. We analyzed existing scales' contents for various cancer patients and outcomes of studies assessing adherence. However, a well-validated scale designed particularly for OACD adherence is still lacking. Most adherence scales used in the studies reviewed contain items focused on measuring patients' medication-taking behavior more than their barriers to medication compliance and beliefs. However, non-adherence to OACDs is a complex phenomenon, and drug-taking barriers and patient beliefs significantly affect patients' non-adherence. To understand the key drivers and predisposing factors for non-adherence, we need to develop a well-validated, multidimensional scale.

Patient–doctor relationship and adherence to capecitabine in outpatients of a German comprehensive cancer center

“…52 , 53 Up till today, a well-validated scale designed particularly for oral anticancer drugs adherence has not yet been developed. 54 Most adherence scales used contain items focusing on measuring patients’ behavior related to taking their medication rather than their perceptions and beliefs. Another major limitation of our approach is the fact that we did not screen for over-adherence, a phenomenon which may lead to adverse reactions and may result from misunderstandings or flawed communication.…”

An Automated Intervention Did Not Improve Adherence to Oral Oncolytic Agents While Managing Symptoms: Results From a Two-Arm Randomized Controlled Trial

“…A common theme in systematic reviews of strategies to improve adherence among oral oncolytic medications is the low quality of the studies. 24,29,30 This trial overcame some of these weaknesses. Patients were recruited from multiple centers, objective measures of adherence were used, and use of IVR systems assured consistent assessment and intervention delivery.…”

Adherence and Coping Strategies in Outpatients With Chronic Myeloid Leukemia Receiving Oral Tyrosine Kinase Inhibitors

“…Reviews describe seven different groups of assessment tools, all of which appear fraught with uncertainty: (a) patient-completed adherence scales, (b) healthcare providers' interviews, (c) patient-reported adherence with diaries and calendars, (d) medication event monitoring, (e) automated voice response, (f) drug and metabolite assays, and (g) prescription databases (Patel et al, 2013). The authors chose a patient-oriented scale even though a well-validated scale designed particularly for oral anticancer drugs is lacking (Huang, Chen, Lin, & Chang, 2016). However, the authors chose the BAAS as a rapid screening tool to gain an understanding of daily routines or periodic prompts, which may be beneficial for adherence (Hall et al, 2016;Marin et al, 2010;Schneider, Hess, & Gosselin, 2011).…”