Epidemiology of head injury

Introduction Head injury is a major cause of morbidity and mortality in all age groups. Currently, there is no effective treatment to reverse the effects of the primary brain injury sustained, and treatment is aimed at minimizing the secondary brain injury that can occur due to the effects of ischaemia, hypoxia and raised intracranial pressure. An understanding of the epidemiology of head injury is essential for devising preventive measures, to plan population-based primary prevention strategies and to provide effective and timely treatment including provision of rehabilitation facilities to those who have suffered a head injury. Epidemiology is the basic science of public health and clinical medicine. It describes the occurrence of health-related states or events, quantifies the risk of disease and its outcome and postulates causal mechanisms for disease in populations. The main function of epidemiology is to provide an evidence-based public health policy thereby guiding clinical practice to protect, restore and promote health. Epidemiological studies have highlighted three important aspects of head injury: (i) socio-demographic factors (age, gender, ethnicity, socio-economic status, geographic location, legislation and enforcement, physical/psychological condition, use of alcohol and drugs); (ii) mechanism of injury (nature of accident or trauma – road traffic accident (RTA), fall, violence, sport injury); and (iii) efficiency of the healthcare system (emergency rescue/ambulance service, in- and out-patient medical care, rehabilitation services). Thus, for devising a prevention programme, we need to identify the risk factors for head injury, the mechanisms and patterns of head injury, possible methods for prevention and the relationship between brain injury and outcome. The aim of this chapter is to describe the descriptive epidemiology of traumatic brain injury (TBI), its causes and preventive measures targeted at the ‘at-risk’ population.