Prevalence and factors affecting cancer medication nonadherence among patients on chemotherapy: A systematic review protocol

Introduction: Adherence to cancer medication varies universally with compliance ranging from 70% to 80%. One of the main reasons cited is the cost of anticancer drugs which many may not be able to bear, and yet the cancer with extensive need of aggressive treatment affects the economic condition of people. Inequitable distribution of disease and service utilization poses the threat of an increase in cancer-related deaths due to poor treatment adherence. The suggested systematic review will assess the cancer medication nonadherence prevalence in cancer patients and identify cost-related, sociodemographic, comorbid conditions, and disease-specific aspects of medication nonadherence.Methodology: Eligibility criteria include any cancer patient on oral or intravenous chemotherapy with or without radiotherapy or surgical intervention. Electronic databases will be searched using predefined search terms to identify relevant studies. Observational, experimental, and qualitative studies (if available) will be included. Methodological quality of included studies will be assessed using the Mixed Methods Assessment Tool by Pace et al. Data synthesis will be done following a predesigned data extraction template, answering the research question. Quality of evidence for an association will be evaluated as per the GRADE system. Meta-analysis will be performed to quantify the association between multiple characteristics and nonadherence, if there is no data heterogeneity (tested using I2 test of heterogeneity). If applicable, meta-regression will be performed to address confounders.Conclusion: The authors have clearly described the methodology and intended outcomes. The findings will help in understanding the potential barriers to successful chemotherapy compliance among cancer patients.