Impact of two decades of humanitarian and development assistance and the projected mortality consequences of current defunding to 2030: retrospective evaluation and forecasting analysis

Official development assistance (ODA) accounts for the majority of humanitarian and development assistance in the world's most vulnerable countries and has played a pivotal role in advancing global health. We aimed to comprehensively evaluate the impact of ODA funding on mortality across the past two decades, and to project the potential consequences of current defunding trends.

We conducted an integrated retrospective evaluation and forecasting analysis using longitudinal panel data from 93 low-income and middle-income countries (LMICs). First, we estimated the association between ODA per-capita funding and mortality outcomes from 2002 to 2021 using a two-ways fixed-effects multivariable Poisson regression model with robust standard errors, adjusted for all relevant demographic, socioeconomic, and health-system covariates. We then assessed age-specific and cause-specific effects, performing extensive sensitivity and triangulation analyses to test the robustness and causal interpretation of results. Finally, we integrated the retrospective impact estimates into validated country-level microsimulation models to forecast mortality under three defunding scenarios up to 2030: a business-as-usual trajectory, a severe defunding scenario, and a mild defunding scenario.