BACKGROUND Traumatic brain injury (TBI) is worldwide an important problem for public health. Current estimates of costs associated with TBI only concern absolute medical costs, regardless of other co-occurring injuries and regular healthcare utilisation that has no relation to the injury.

OBJECTIVES : This study aims to provide more specific information on costs of TBI by determining the incremental cost of TBI during the first year after a traffic accident. Furthermore, identification of factors associated with medical costs of TBI is pursued.

METHODS : Analyses were performed on administrative data for traffic victims hospitalised in Belgium between 2009 and 2011. Medical costs attributable to the accident are estimated over the period of one year post-injury by subtracting costs of pre-injury healthcare utilization from post-injury costs. Cases with TBI were matched to similar controls without TBI to determine the incremental cost. Both aims of this study were assessed using regression analysis.

RESULTS : The incremental cost of TBI is estimated to range between €10 042 (95%CI [8198 ; 11 887]) and €21 715 (95%CI [13 889 ; 29 540]) (indexed to 2018 euros). Age, problems with self-reliance, survival status, the occurrence of acute events and severity of TBI are significant predictors of medical costs. As to healthcare utilisation, MRI usage, inpatient rehabilitation, residing in nursing homes post-discharge and readmissions to acute hospital stand out as having most influence on costs.

CONCLUSIONS : This study reveals a considerable incremental cost of TBI. The insights contributed by this study can support informed decision-making on the allocation of healthcare resources, reasoned budgeting, identifying best practices and targeted efforts towards prevention of TBI. This knowledge might even expose opportunities for cost saving by providing estimates of the costs that can be averted by solid prevention policies.