Socioeconomic differences and determinants of reimbursable out-of-pocket expenditures: a prospective cohort study within the BabyGel trial.

Introduction: Direct non-medical out-of-pocket costs, such as transport and subsistence, can delay access to child healthcare and worsen health outcomes. This study examined socioeconomic differences in reimbursable out-of-pocket expenditure (OOPE) within the BabyGel trial in eastern Uganda. Methods: We conducted a prospective cohort study nested within the BabyGel trial (2022-2024) in Budaka and Mbale districts. Reimbursed transport and inpatient subsistence costs were recorded for 2675 mother-baby pairs. Socioeconomic status (SES) was derived using multiple correspondence analysis and categorised into low, middle and high SES. Gamma and quantile regression models were used to examine differences in OOPE. Results: We included 2675 women (mean age 25 years (SD 6)). Children from low SES households had an average of 3.0 hospital visits, while those from middle SES households had the longest average hospital stay of 6.0 days. Low-SES households had 82% higher OOPE (exp(b)=0.82; 95% CI 0.73 to 0.93). Secondary education and shorter distances to water source were associated with 10% lower OOPE, while diarrhoea increased OOPE by US$1.49 at the 25th percentile. Conclusion: Reimbursing transport and subsistence costs can reduce financial barriers to newborn care, particularly benefiting low-SES households. These findings highlight the potential of targeted financial support mechanisms to promote equitable access to child healthcare in low-resource settings.