When it comes to post-injury disability, the disparity between acknowledged need for epidemiologic data and apparent investigative effort is remarkable.^1–3 Defining the nature of a health problem is the first step in its ultimate management.⁴ A recent issue of Epidemiologic Reviews highlighted the importance of garnering the full spectrum of evidence that can help decision makers, the media, and the public appreciate the impact of injuries.⁵ Yet robust information about non-fatal consequences of injury—particularly disability—was acknowledged as an unmet challenge for epidemiologists. What may account for this?

The answer may lie in the fact that in contrast to well established approaches addressing aetiological questions relating to injury,⁶ the discourse on appropriate methods to investigate post-injury disability is complex and unresolved. A recently published textbook concludes the field is diverse, inconsistent, and lacks depth.⁷

The reasons for this situation are not hard to find. Twenty five years ago, an essay on the theory of knowledge noted “The more a science deals with humanity, the less highly resolved it is, and the less its truths are susceptible of cogent proof”.⁸ This is a particularly apt description of disability—a construct defined not only by the specific …