The Burden and Socioeconomic Inequality in Catastrophic Out-of-pocket Health Expenditure in Post-Pandemic Nigeria

Abstract Out-of-pocket (OOP) payments are the primary health financing mechanisms in Nigeria. This study—the first national analysis using post-COVID-19 data—examines the incidence and socioeconomic inequalities in catastrophic health expenditure (CHE) among Nigerian households using data from the nationally representative Nigeria General Household Survey 2023/2024. We estimated the proportion of households facing CHE using both household budget share (BS) and capacity-to-pay (CTP) approaches, with thresholds set at 10% and 40%, respectively. We assessed socioeconomic inequality in CHE incidence using the concentration index (CIX) and decomposed the CIX of CHE incidence using Wagstaff et al.’s (2003) approach. Our analysis show that households CHE incidence was 45.5% (95% CI: 43.5%–47.4%) and 43.1% (95% CI: 41.1%–45.0%) using the 10% BS and 40% CTP approaches, respectively. The Wagstaff-normalized CIX revealed pro-poor distributions of − 0.152 and − 0.178 for the BS and CTP approaches, respectively. Our decomposition analysis revealed that socioeconomic inequality in CHE was largely driven by female-headed households, larger households, households with elderly member(s), and rural residences. These findings indicate that OOP payments continue to impose a catastrophic financial burden on a substantial proportion of Nigerian households, particularly those with elderly individuals as well as female-headed, poor, large, and rural households. The intensity of these payments is also deeply impoverishing, highlighting the urgent need for targeted financial protection measures—such as the establishment of a comprehensive health insurance program for elderly Nigerians—to safeguard vulnerable populations and promote equitable access to healthcare.