In this cross-sectional study, we sought to determine the correlation between out-of-pocket costs of cancer treatment and the mental health of patients (Fig. 2). Despite the significant prevalence of depression and anxiety in our patients undergoing cancer treatment, we found no correlation between overall out-of-pocket expenditures and mental health. However, when analyzed by individual variables, specific spending seems to impact the levels of anxiety, depression and stress in cancer patients.
Our study population was mostly female (61%), with a mean age greater than 50 years, findings that are consistent with those reported by other studies involving cancer patients [13, 20–28]. There was greater participation by people who claimed to be white (60%), and most of the study population was married [28]. According to the literature, the main comorbidities of cancer patients are systemic arterial hypertension, diabetes mellitus and dyslipidemia, observations that were confirmed in our study [22]. Most of the patients included in our study were employed and received approximately 1 to 2 times the minimum wage, results that are similar to those in another Brazilian study [27]. However, unlike other studies, in which most of the population received health care through a private health network [13, 16, 22], our study evaluated the out-of-pocket financial impact of cancer treatment on patients who received health care through the public network. Another study evaluated this same impact, concluding that the majority of the affected population was elderly, female, and unemployed or retired and lacked medical insurance [24].
Regarding the characteristics of neoplasms, the most prevalent primary cancer site was the breast, followed by the gastrointestinal tract; these findings are similar to those in other studies, in which the main site was the breast, followed by the gastrointestinal tract, prostate and lung [13, 16, 24–26].
Our study found important prevalence rates for depression and anxiety in cancer patients, and although overall out-of-pocket spending was not directly correlated with mental health, when analyzed individually, specific spending impacted the levels of anxiety, depression and stress in cancer patients. Previous North American studies have shown that most cancer survivors report financial concerns associated with greater chances of psychological distress [20], which is considered a risk factor for mortality [21]. Higher financial toxicity was also associated with higher levels of depressive and anxiety symptoms, greater concern and distress, lower self-efficacy in coping with cancer, and poorer health-related quality of life [13, 22]. In addition, financial toxicity was also considered a significant predictor of patient-reported anxiety, fatigue, and physical and social dysfunction [16]. A systematic review published in 2019, which included 9 studies involving 11,544 cancer survivors, reported that the relationship between financial toxicity and psychological symptoms was examined in 8 studies, 6 of which reported a positive relationship between financial toxicity and depression and 3 of which found a positive association between financial toxicity and anxiety. Limited evidence was found for an association between financial toxicity and stress, fear of recurrence, spiritual suffering, pain and general symptom load [23].
In our study, there were positive correlations between expenditure on medications and time purchasing medications and the HADS score and a positive correlation between time purchasing medications and stress thermometer score. Thus, we can hypothesize that the extra expenditure on medication, not provided by the SUS, and the time spent acquiring those medications are factors directly or indirectly related to higher levels of anxiety, depression and stress. On the other hand, a negative correlation was found between telephone costs and the HADS score, which may suggest that speaking on the phone may be a protective factor against anxiety and depression in our study population. The strongly significant correlation between the HADS score and stress thermometer score also indicates that anxiety, depression and stress tend to manifest in a concomitant and interconnected manner.
Our study allowed us to establish a more intimate relationship between the variables and depression and anxiety levels. By analyzing “financial toxicity” by its components, such as transportation, food, telephone and medication costs, we were able to identify the areas in which patients were most affected and in which more investment and research are needed.
Recent studies on the subject have evaluated financial toxicity using various tools. The Comprehensive Score for Financial Toxicity (COST) [16, 22] subjectively evaluates patient expenses through a series of questions regarding the patient's financial situation. Other studies address the subject by grading (from 1 to 10) the financial situation of patients [26] or asking questions similar to those on the COST [20, 26]. Some studies opt for more objective approaches regarding patients’ financial situation. Data on bankruptcy from national banks [21] and calculations of the percentage of a family’s average income spent on health services [28] are examples of more pragmatic approaches.
Analogous to these studies, we chose to adopt a more objective approach, allowing a more robust evaluation and the establishment of comparisons between the expenses of patients. Additionally, we removed the perception of patients regarding their expenses, allowing a more accurate assessment of their feelings.
We chose to include components related to the time spent by individuals in activities related to treatment. The reason for this approach was that cancer is a condition that also affects the so-called economically active population, a fact confirmed by the median age of our study population, 57 years. In a dynamic and capitalist world, time is increasingly linked to money, thus being an indispensable component in the evaluation of financial toxicity. However, in other studies evaluated, we found no such factor.
Regarding the results, the higher were the telephone expenses, the lower was the HADS score. In turn, the cost of medications and the time spent purchasing medications were positively correlated with the HADS score. This finding can be explained by the use of the telephone as a leisure tool, helping to combat mental illnesses. Regarding medications, the amounts charged for medications for cancer treatment and/or support may affect the financial situation of patients, resulting in behavioral changes such as depression and anxiety.
Given this, it is evident that the availability of medications for the treatment of cancer through the SUS and for the health of the Brazilian population in general still requires adjustments. Despite improvements in recent years regarding the range of medications offered by the SUS, the topic still requires substantial attention from the responsible agencies.
Our study has some limitations. First, because of the observational nature of our study, it is impossible to establish cause and effect relationships and to exclude the possible presence of biases and confounding factors. Our questionnaires, mainly related to cost-time, demand that patients remember various expenses and situations, which may be a source of recall bias. Additionally, the context of the COVID-19 pandemic imposed 2 challenges that affected our study: the proportion of patients provided health care through the SUS and research protocols because due to the pandemic, several patients missed their follow-up, especially in the research protocol group; furthermore, it is uncertain how restrictive measures and the pandemic environment itself may have influenced the mental health of patients. Finally, our population of patients represents only a portion of patients undergoing cancer treatment, which includes patients from several other health centers that may have their own protocols for providing assistance to patients.