Battle C, Hutchings HA, Driscoll T, et al. - Via a stepped wedge feasibility trial of adult blunt chest wall trauma patients presenting to the emergency department (ED) with no concurrent, life-threatening injuries, experts evaluated the feasibility and acceptability of a definitive impact trial examining the clinical and cost-efficiency of a new prognostic model for the management of subjects with blunt chest wall trauma in the ED. Via the intention-to-treat principle quantitative data were examined. A total of 176 patients were recruited and recruitment targets were attained at all sites. In 96% of intervention cases, clinicians practiced the model. All feasibility criteria were completely or partly met. No statistically important variations between the control and intervention periods were found following adjustment for predefined covariates. The qualitative analysis reflected that STUdy evaluating the impact of a prognostic model for Management of BLunt chest wall trauma (STUMBL) was well-received and clinicians would support a specific trial. Collecting data on intervention costs, health-related quality of life and healthcare resource use was possible. Therefore, a fully powered randomized clinical trial of the STUMBL score was feasible and required to clinicians. Minor methodological modifications would be created for the full trial.