Table 1.

Presentation of the Research Results

	Author / year/country	Method	Objective	Sample	Main results
A2	Egestad H, Nieder C. 2015. Norway	Prospective Study	To analyze the deterioration of health-related quality of life in patients with head and neck cancer due to the financial issues associated with treatment.	67 patients with head and neck cancer	89% of patients provided treatment data on financial difficulties; there was a tendency to financial difficulty in the case of men under 65 years old; the highest score of financial difficulty was observed in single patients and closer to the end of treatment.
A2	Kelly et al., 2018; USA	Descriptive cross-sectional study	To describe discussions of costs of oncology treatment between patients and oncologists in real time and analyze whether these discussions caused discomfort to patients or not.	96 patients with previously treated breast, lung or metastatic colorectal cancer.	28% of oncologists felt comfortable discussing costs; 6% asked patients regularly about financial difficulties; 80% of patients wanted to receive information about costs and 84% reported that such conversations would be important; 72% of patients answered that no healthcare professional discussed the costs with them.
A3	Souza et al., 2017; USA	Methodological research	To correlate patient-reported financial toxicity with health-related quality of life (HRQOL) and investigate whether the Comprehensive Score for financial Toxicity (COST) measure was related to its psychometric properties.	375 patients with stage IV cancer	Correlation with HRQOL indicated that financial toxicity was a clinically relevant, patient-centered outcome.
A4	Zafar et al., 2013; USA	Exploratory and observational study	To report the experiences of insured cancer patients seeking co-payment assistance and analyze the impact of health conditions on well-being and treatment.	254 patients with solid tumors receiving chemotherapy or hormone therapy.	75% of patients applied for drug payment assistance; 68% reported reduced paid activities, 46% reduced spending on basic food and clothing, 46% used their savings, and 17% sold goods or properties to pay for treatment costs. To save money, 20% bought less than the total of prescribed medication; 19% bought part of the prescribed medication; 7% of patients avoided procedures; 9% avoided exams; 4% ignored ways to save money.
A5	Honda et al., 2018; Japan	Methodological research	To analyze the viability of using the Japanese version of the COST questionnaire in the measurement of financial toxicity among Japanese cancer patients.	11 cancer patients undergoing chemotherapy.	Five (45%) patients had degree 1 of financial toxicity and two (18%) patients had degree 2. The COST measure showed good internal consistency with Cronbach’s α of 0.87.