Injury is the leading cause of premature death in New Zealand accounting for over 75% of deaths among youth and the majority of deaths and hospitalisations up to middle age. Yet research studies large enough to quantify the patterns of risks associated with life-threatening injuries are rare and typically resource-intensive. The New Zealand Blood Donors' Health Study and the Fletcher Challenge - University of Auckland Heart and Health Study (>30,000 participants) were established with funding from HRC 12-18 years ago to address this challenge. We will actualise the unique potential of these studies by linking participants' baseline data on potentially important predictors to information on injury-related hospitalisations or deaths that have accrued since. The evidence generated, at a fraction of the cost of traditional research of this scale, will help develop and better target injury interventions in New Zealand, particularly those due to road crashes, falls, self-harm, and traumatic brain injuries.