Catastrophic health expenditure remains a critical challenge for informal sector workers in sub-Saharan Africa. The Lagos State Social Health Insurance Scheme was established to improve financial protection, but its specific impact on informal traders requires robust evaluation. A prior study suggested a potential protective effect, yet methodological limitations necessitate replication for more definitive evidence. This replication study aimed to assess the impact of the Lagos State Social Health Insurance Scheme on the incidence of catastrophic health expenditure among informal traders in Alimosho Local Government Area. The primary objective was to determine whether scheme enrolment significantly reduced the proportion of households experiencing catastrophic expenditure over a 24-month period. A longitudinal, quasi-experimental design was employed. A cohort of informal traders, comprising both enrolled and non-enrolled individuals, was followed. Data were collected via structured questionnaires at baseline and follow-up. Catastrophic health expenditure was defined as out-of-pocket health expenditure exceeding 40% of a household's capacity to pay. Comparative and multivariate regression analyses were performed. Enrolment in the scheme was associated with a reduction in catastrophic expenditure incidence. The proportion of enrolled households experiencing catastrophic expenditure was 8.2 percentage points lower than that of non-enrolled households at follow-up. However, a substantial minority of enrolled households still faced catastrophic costs, primarily due to uncovered services and co-payments. The replication confirms that the scheme provides a measurable, though incomplete, protective effect against catastrophic health expenditure for informal traders in this setting. It mitigates financial risk but does not eliminate it entirely. Policy efforts should focus on expanding the scheme's benefit package to cover a wider range of services and reviewing co-payment structures. Further research is needed to understand the persistent financial risk among a subset of enrolled households. catastrophic health expenditure, health insurance, informal sector, replication study, financial protection, Nigeria. This study provides replicated evidence on the effectiveness of a state-led health insurance scheme in a key population, informing policy adjustments for improved financial risk protection in Nigeria and similar contexts.
Habimana et al. (Tue,) studied this question.