Economic, Equity, and Policy Impacts of the Prevention and Control of Obesity-Associated Cancers in Mexico and Peru (EFFECT-O): A Mixed Methods Study Protocol (Preprint)

BACKGROUND Obesity-related cancers (ORC) are increasing in low- and middle-income countries (LMICs). Individuals living with ORC frequently face high out-of-pocket health spending, limited financial protection, and serious health-related suffering (SHS). However, evidence on the economic burden and SHS associated with ORC in LMIC settings remains limited. OBJECTIVE This study aims to quantify out-of-pocket costs and catastrophic health expenditure among adults with breast, colorectal, cervical, and gastric cancers in Mexico and Peru, and to characterize SHS and examine its association with economic burden. METHODS This mixed-methods, multi-country study is conducted at cancer care institutions in Mexico and Peru. The quantitative component includes an interviewer-administered survey collecting data on sociodemographic characteristics, health service use, out-of-pocket spending, financial burden, quality of life, and cancer-related distress. The qualitative component consists of in-depth, semi-structured interviews to explore experiences of suffering, coping strategies, and barriers to care, including access to palliative care. Eligible participants are adults (≥18 years) with breast, colorectal, cervical, or gastric cancer who are receiving treatment at participating centers. Quantitative data are analyzed using descriptive statistics and two-part regression models. Qualitative data are analyzed using thematic analysis. RESULTS Data collection occurred from October 2023 to May 2024. Data analysis is currently ongoing, and results are expected in 2026. CONCLUSIONS This study will generate policy-relevant evidence on the economic burden and SHS associated with ORC in Mexico and Peru. The findings will inform financial risk protection strategies and support the integration of palliative care across the cancer care continuum to reduce avoidable suffering in LMIC settings.