Structural Determinants of Occupational Health Inequalities Between Formal and Informal Sector Workers in Nigeria: A Social Epidemiological Analysis

Occupational health inequalities between formal and informal sector workers represent one of Nigeria's most persistent and poorly studied public health challenges, yet the structural determinants driving these inequalities lack rigorous social epidemiological analysis. This doctoral study applied the Commission on Social Determinants of Health Framework to examine structural and intermediary determinants of occupational health inequalities across Nigeria's labor market segments. A nationally representative cross-sectional survey was conducted with 3,200 workers across all six geopolitical zones using multistage probability sampling. Survey instruments assessed occupational hazard exposure, health outcomes, health service access, social protection status, and structural position indicators. Complementary qualitative case studies were conducted in six labor market settings. Poisson regression with robust variance estimation and inequality decomposition analysis were the primary analytical methods. Health outcome inequalities across employment formality, gender, and geopolitical zone dimensions were quantified and decomposed. Structural determinants including labor market informality, gender-based occupational segregation, regulatory enforcement capacity, and regional governance capacity explained 67.4 percent of health outcome inequality variance. This study provides the most comprehensive social epidemiological analysis of Nigerian occupational health inequalities to date, contributing an original structural inequality analysis framework. The study calls for equity-oriented occupational health policy reform, enforcement capacity building across state ministries of labor, and universal social protection extension to informal workers. Keywords: occupational health inequalities, social epidemiology, informal sector, structural determinants, Nigeria.