Economic burden of road traffic injuries across income groups and injury severity levels: a cross-sectional study in Tehran Province, Iran

Road traffic injuries impose a considerable economic burden in Iran; however, evidence on the distribution of direct and indirect costs across income groups, particularly after hospital discharge, remains limited. This study aimed to compare the economic burden of road traffic injuries across income groups and injury severity levels among patients in Tehran Province, Iran. A cross-sectional descriptive-analytical study was conducted on 434 systematically selected patients admitted to hospitals due to road traffic injuries in Tehran Province, Iran (2023–2024). The study collected data on direct medical costs, direct non-medical costs, and indirect costs, and injury severity (ISS) and income quartiles through a series of structured telephone interviews and hospital records. The costs were measured using the human capital method and analyzed from the patient perspective (out-of-pocket medical and non-medical costs and productivity losses) and the societal perspective (total healthcare costs, including patient and healthcare system costs, plus productivity losses) to compare the economic burden of road traffic injuries across income groups. This study included 434 patients admitted for road traffic injuries, with a mean age of 38.3 years and mostly insured males. Although inpatient costs were fully covered by insurance, substantial socioeconomic differences were observed in the overall economic burden. Indirect costs increased across income groups, from $9,965 in the lowest to $18,808 in the highest quartile, while out-of-pocket expenses after discharge were higher for lower-income patients. Costs rose sharply with injury severity, with inpatient expenses ranging from $2,870 for mild to $16,288 for critical injuries, and indirect costs from $2,477 to $23,477. Overall, financial burden increased with income and injury severity. Indirect costs accounted for up to 73% of the total economic burden from the societal perspective and up to 92% of the total financial burden from the patient perspective. The economic burden associated with road traffic injuries in Iran is considerable, and indirect and post-discharge costs fall particularly on lower socioeconomic groups. The severity of injury contributes to these costs, which reflect inadequate financial protection beyond hospital cover.