Table 2.

A priori concepts derived from existing models

References	Direct costs	Indirect costs	Material resources	Psychological response	Financial coping behavior	Financial outcome	Health outcome	Risk factors
Hanratty et al. (2007) [28]	Rising health care costs and increasing health care use			Financial strain: the subjective perception of financial hardship
Kankeu et al. (2013) [26]	Economic consequences: Direct costs	Economic consequences: Indirect costs	Social resources (e.g assistance from others)		Coping strategies (e.g. Intra- and inter- household labor substitution; Hiring other labor and other strategies; Reducing/delaying consumption of non-health goods and services (food, education, electricity, leisure, etc.); Use of savings; Sale of assets; Borrowing; Delaying investments)			Treatment seeking behavior: Yes or No
Gordon et al. (2017) [2]	Currency (monetary) values of OOP costs		Percentage of OOP costs to income ratios	Perceptions of cancer-related financial burden and psychological impact	Tangible solutions to ease financial burden such as increasing debt levels, borrowing money from family or friends, selling assets
Altice et al. (2017) [3]	Material conditions: Increased OOP expenses	Material conditions: Lower income that can result from the inability to work during/following cancer treatment		Psychological response: Response to the increase in household expenses that must now be managed as patients navigate cancer care	Coping behaviors: patients adopt to manage their medical care while experiencing increased household expenses during/following cancer care	Medical debt/bankruptcy
Santacroce et al. (2018) [29]	Monetary: Direct costs	Monetary: Indirect costs		Patient-reported: Psychosocial	Patient-reported: Financial coping
Witte et al (2019) [33]	Objective financial burden: Direct costs (OOP)	Objective financial burden: Indirect costs (income loss)	Subjective financial distress: Material	Subjective financial distress: Psychosocial	Subjective financial distress: Behavioral
Yabroff et al. (2018) [34]								Level of risk factors: patient/family, provider and care team, health care system, employer, state and national policy
Thomas et al. (2019) [27]	Direct (medical) costs, indirect (non-medical) costs			Biological responses to stress	Financial coping behavior: Treatment non-adherence			Medical insurance
Imber et al. (2020) [42]	Direct costs: Patient’s OOP responsibilities owing to prostate cancer	Indirect costs: Opportunity costs of prostate cancer	Individual economic circumstances: Baseline wealth, pre-existing debts and economic reserve	Expectations of possible financial burdens: Knowledge and perception of the economic effect that a prostate cancer diagnosis will have on one’s family				Patient-specific values and self-management behaviors
Belcher et al. (2020) [23]				Distress: General stress, cancer-specific stress, cancer worry, depression, anxiety	Inability to make ends meet, not enough money for necessities, cutbacks and adjustments			Functional health: physical function; symptom burden; symptom interference; comorbidities; social role, ability
Newton et al. (2020) [31]	Monetary measures of financial toxicity: direct medical costs, direct non-medical costs	Monetary measures of financial toxicity: indirect costs		Subjective measures of financial toxicity: Distress	Objective measures of financial toxicity: Coping mechanisms	Subjective measures of financial toxicity: Indebtedness	Subjective measures of financial toxicity: Health outcomes	Treatment seeking behavior: Diagnosis, health literacy, self-advocacy, personal financial circumstances, perception of the health system, clinician's recommendations, private health insurance status, proximity to treatment centers
Tucker-Seeley and Thorpe (2019) [43]			Material domain: Material hardship, making ends meet, material disadvantages	Psychosocial domain: Financial stress, financial worry, financial satisfaction	Behavioral domain: Financial adjustments, financial planning, spending/consumption
Santacroce and Kneipp (2019) [30]	Financial costs: Direct costs	Financial costs: Indirect costs		Financial distress: Biological response to stress	Financial distress: Financial coping behavior	Family financial outcomes: Recent material hardship and impoverishment	Parent health outcomes: Symptoms, quality of life, risk for disease onset; Child health outcomes: symptoms, quality of life, relapse	Pre-existing parent factors: age, gender, language, marital status, work status; Pre-existing family factors: residence, income, assets, debts, number of children, general health; Post-cancer diagnosis: treatment decision and initiation
Carrera et al. (2018) [32]	Objective financial burden: Expenditures on drug costs, other direct medical costs, treatment costs		Subjective financial distress: Wealth – wages, salaries or replacement income; savings and assets	Subjective financial distress: anxiety and discomfort
PDQ Adult Treatment Editorial Board (2002) [5]	Medical costs, non-medical costs			Financial strain and distress		Formal bankruptcy	Health outcomes	Pre-illness health, assets, debt, income, illness or injury, medical insurance, treatment choice
Pisu et al. (2010) [25]	Direct costs: medical costs, non-medical costs, time costs	Time costs (at work) Indirect costs: Productivity losses due to cancer					Psychosocial cost: loss of quality of life
McNulty and Khera (2015) [45]				Patient/family: Increased stress and uncertainty	Spending savings/retirement funds, borrowing money, losing home/selling property, lifestyle changes, avoiding purchases, reduced spending on food and clothing, changes in decision making/priority selling; Cancer treatment: decreased adherence to cancer treatment	Incurring significant debt, bankruptcy	Patient/family: Parent cost, disability Decreased health related quality of life: Increased stress, uncertainty, anxiety and depression, demands on the caregiver	Risk factors: Patient/family socio-demographics, financial/employment, environmental/logistical, cancer and disease related
Lentz et al. (2019) [24]	Costs related to medical, surgical and radiation treatment, including costs of supportive care, end-of-life care	Material consequences: Reduced income		Psychological consequences: Distress	Maladaptive coping: Skipping or reducing medication doses, adjusting non-medical spending	Material consequences: Depletion of savings, debt, bankruptcy	Psychological consequences: reduced quality of life	Causes: Baseline factors: demographics, health, socioeconomic status Cancer: type and stage Medical insurance status: Premiums, deductibles, coinsurance, absence of

OOP out of pocket