In 2009, HRC funded a study (BIONIC) to find out the frequency of TBI in a nationally representative population and to follow-up all patients over six months to explore the effects of TBI. The original funding application was based on published estimates of the size of the problem. Halfway through recruitment, the actual number of cases of TBI in the BIONIC study was 34% higher than anticipated, clearly highlighting the importance of this study. This application aims to ensure that the additional cases are identified and assessed, to capture accurate incidence rates per annum and to complete a further follow-up assessment at 12-months for all BIONIC participants. The year following a brain injury has been revealed as the critical recovery period, therefore it is important to follow patients up to 12 months post injury to obtain a realistic picture of outcomes and burden of TBI.