Catastrophic health expenditure (CHE) is a major obstacle to universal health coverage in Nigeria, especially for informal sector workers. The Lagos State Social Health Insurance Scheme (LSSHIS) was established to offer financial protection, but its specific effect on vulnerable groups such as market traders remains inadequately studied. This study aims to assess the impact of LSSHIS enrolment on the incidence of CHE among informal sector traders in Alimosho Local Government Area over a 24-month period. Its primary objectives are to compare the incidence of CHE between enrolled and non-enrolled traders, to identify socio-demographic factors associated with CHE, and to explore participants' experiences with the scheme. A prospective cohort study will be conducted over 24 months. A minimum of 440 informal sector traders (220 enrolled in LSSHIS and 220 not enrolled) will be recruited from major markets in Alimosho LGA. Data will be collected via interviewer-administered questionnaires at baseline, 12 months, and 24 months. CHE will be defined as out-of-pocket health expenditure exceeding 40% of a household's capacity to pay. Quantitative data will be analysed using multivariate logistic regression, while qualitative data from a participant subset will be analysed thematically. This is a study protocol; no empirical findings are available. The anticipated outcome is a lower incidence of CHE among the enrolled cohort compared to the non-enrolled cohort over the study period. The study will produce longitudinal evidence on the effectiveness of a state-led social health insurance scheme in reducing financial risk for a large, typically underserved occupational group. Findings will inform potential policy adjustments within the LSSHIS and provide evidence for scaling up enrolment strategies targeting the informal sector. catastrophic health expenditure, health insurance, informal sector, financial protection, Nigeria, prospective cohort study This protocol outlines a study designed to generate specific evidence on the impact of a sub-national health insurance scheme on financial risk protection for informal workers, a group critical to achieving universal health coverage in Nigeria.
Diop et al. (Thu,) studied this question.