Defining and Measuring Financial Toxicity in Low- and Middle-Income Countries.

Purpose: Financial toxicity (FT) of cancer treatment likely affects more patients in low- and middle-income countries (LMICs); however, most of the research on FT comes from high-income countries, which may not apply to LMICs. The causes and consequences of FT in patients with cancer in LMICs remain understudied.

Methods: Following PRISMA guidelines, we searched MEDLINE, Web of Science, and CINAHL for FT literature in cancer originating from LMICs from inception until the end of 2023, and documented the different definitions used to define FT in LMICs, and the magnitude of FT documented using those definitions. LMIC was defined using the World Bank Country and Lending Group classification.

Results: Sixty-eight studies met the inclusion criteria. Studies on FT in cancer originating from LMICs have increased in recent years (>75% studies published 2020 onward) and used varying criteria to define FT, broadly categorized into five themes. Majority of the studies defined FT in terms of catastrophic health expenditure (45%) or household impoverishment (10%), while 26% of the studies used the Comprehensive Score for Financial Toxicity tool, developed and validated in US patients, to measure FT in LMIC settings. Twenty-six percent of the studies defined FT in terms of coping mechanisms and 10% in terms of subjective financial burden. The magnitude of FT in patients with cancer was substantial irrespective of the definitions used.

Conclusion: This review synthesizes the different definitions of FT for LMICs that have been used in the literature so far. We conclude that the definitions that capture the coping mechanisms or hardships might reflect the magnitude of FT better than absolute dollar values or relative percentages of expenditures. Future studies can use our results to devise locally tailored definitions of FT.