Reference
Xiomara Skrabal Ross, Kate M. Gunn, Vijayaprakash Suppiah, Pandora Patterson, Ian Olver. A review of factors influencing non-adherence to oral antineoplastic drugs Supportive Care in Cancer (2020) 28:4043–4050
Summary
This paper reviewed the data available to provide an updated summary of the factors influencing non-adherence to oral antineoplastic drug (OAD) regimens in people with cancer. The identified factors were classified as modifiable (side effects, forgetfulness and poor knowledge about OADs) or non-modifiable factors (out of pocket costs, age, regimen complexity). Despite limitations of the studies and the need for further research, this review may serve as a guide to oncology healthcare professionals in identifying and implementing support interventions to encourage patient adherence to OADs. Setting and starting point Medication adherence is a complex and multifactorial phenomenon influenced by factors such as treatment, the patient and the healthcare system. It is defined as the extent to which an individual’s drug-intake behavior corresponds to what was agreed upon with the healthcare professional. To date, more than 400 determinants of oral medication adherence have been identified. In chronic, non-oncological diseases, it is estimated that only 50% of patients adhere to their prescribed medication. Similarly, in oncology, there is evidence of OAD adherence rates being as low as 46%. OADs include oral chemotherapy, targeted therapies, and hormonal therapies. One of the many advantages of taking antineoplastic drugs by mouth as opposed to the intravenous route is most certainly the ease of home administration. That said, oncology facilities generally do not follow standardized processes to monitor OAD adherence, which is a challenge for both healthcare professionals and patients. Research-based knowledge of the factors that reduce OAD adherence would benefit the practice of oncology. Such knowledge would allow for an accurate individual assessment and the development of interventions and strategies that could translate into better use of drugs and improved treatment outcomes for patients. The aim of this review is to provide an up-to-date summary of the main reasons for non-adherence to OADs in people with cancer.
Study design
This review was carried out on the Medline, Embase, Emcare e PsychINFO electronic databases. The following search terms were used to identify relevant studies: “systematicreview, review,” “reasons/determinants/factors,” “adherence, non-adherence, nonadherence, compliance, noncompliance,” “oral chemotherapy/oral endocrine/hormonal therapy/oral antineoplastic drugs,” and “cancer, oncology.” An independent assessment of the eligibility of the articles was conducted by two reviewers. Data from the eligible publications were independently extracted by the reviewers and organized according to the main categories of reasons for OAD non-adherence.
Results
The review included 3 systematic review articles focused on patients with different types of cancer, with a majority of studies dealing with breast cancer. It also included 2 research studies, with one focused on oral chemotherapy only in patients with Chronic Myeloid Leukemia and the other focused on patients with different cancer diagnoses, including Chronic Myeloid Leukemia. Most of the included studies (3/5) strongly recommend providing patient education regarding the use of OADs as part of standardized procedures, which also included monitoring of OAD adherence and side effects. The main causes of OAD non-adherence identified in the studies were classified according to the WHO framework for factors influencing medication adherence and were divided into modifiable and non-modifiable reasons. For the purposes of this review, modifiable reasons are defined as “those factors of OAD non-adherence that can be modified by the patient or in collaboration with their carers and / or healthcare professionals”. The modifiable factors identified are: side effects and drug toxicity, forgetfulness, poor therapeutic education and poor knowledge of the disease and treatment. The non-modifiable factors are: age, socio-economic condition, complexity of the regimen and duration of therapy.
News
The review was conducted in order to be used as a guide for oncology health professionals and researchers in addressing modifiable factors for OAD non-adherence, such as managing side effects, forgetfulness, and knowledge of the regimens. It is also important that healthcare professionals are aware of non-modifiable factors.
Limitations
This work reviewed a greater amount of research on adherence to OADs with Chronic Myeloid Leukemia and breast cancer patients. In addition, variations in adherence cut-off rates and different assessment methods exist between studies. Finally, the factors influencing adherence to hormonal and non-hormonal OADs were NOT analyzed separately. It may be that specific factors influence non-adherence behaviors for each type of OAD, considering the evidence of higher rates of non-adherence to regimes for non-hormonal drugs as opposed to hormonal drugs.
Future prospects
Medication adherence is a multifactorial phenomenon. This review found a number of factors that explain non-adherence to OADs. While more research with rigorous methodology and diverse cancer types is needed to increase the understanding of factors that influence non-adherence to OADs, this study may serve as a guide to oncology health professionals. It may assist them in discussing OAD adherence with patients and may also help guide them to the appropriate medication adherence support measures, such as informational resources, reminders, and where available, internet, and/or mobile-based adherence interventions.
Edited by Gaetano Auletta
