It is estimated that between 500 and 700 people sustain a traumatic spinal cord injury (SCI) in the UK each year (Smith 1999). In the USA, there are approximately 10,000 new cases per year (McDonald 2002). SCI can occur at any age, the effects are usually permanent and currently there is no cure (Harrison 2000). The modal age of an SCI is 19 years and the lifetime cost of care may consequently be quite high. The average lifetime cost of treating a person with SCI has been estimated at between US$500,000 and US$2 million, depending upon the location and extent of the injury (McDonald 2002). The most common mechanism of injury is a sudden unexpected impact or deceleration (e.g. in a road accident or domestic fall). Further neurological deterioration, resulting from lesion extension after the initial injury can occur naturally in about 5% of cases (Harrison 2000) and complications associated with the systemic effects of SCI can lead to respiratory compromise. Significant delays and complications (sometimes leading to admission to an intensive therapy unit [ITU]) can also arise as a result of inappropriate or poorly informed management.

Immediate care
The first 24 hours following injury constitute 'immediate care'. It is during this time that the majority of complications can occur (Harrison 2000). Decisions made at the scene of the injury can have a profound impact on the outcome for and ongoing management of individual patients, so care pathways are crucial. It has been suggested that spinal injury units (SIUs) may influence the pre‐transfer care of people with SCI by liaising closely with colleagues in general hospital units, and by providing advice and information (Talbot 1979).

Spinal injury units
The concept of the specialist SIU was first conceived in the 1930s and 1940s by Sir Ludwig Guttman in the UK, and by Donald Munro in the USA (Smith 1999). In the UK, the National Spinal Injuries Centre (NSIC), based at Stoke Mandeville Hospital, was opened in 1944. There are currently 12 spinal injury units (SIUs) in the UK and Ireland which provide comprehensive acute, rehabilitation and continuing care facilities and services. In the USA, the Model Regional Spinal Cord Injury Care System programme was established in the early 1970s. At present, 16 centres are funded by the National Institute on Disability and Rehabilitation Research. The goal of these centres is to provide care within 24 to 48 hours for victims of SCI within a defined system (Donovan 1994).

The following minimum standards of SCI care were agreed by all senior medical and paramedical staff at the NSIC in July 2001 (personal communication, Brian Gardner): 1) admission of all newly injured SCI persons in the SCI centre with 24 hours of injury, provided they are fit to make the journey by ambulance; 2) readmission of all SCI persons requiring inpatient hospital treatment into a SCI centre, provided they are fit to make the journey by ambulance; 3) review of SCI persons annually by outreach or a visit to the NSIC; 4) all treatments of accepted value to SCI persons to be available in the SCI centre. The UK Spinal Injuries Association (SIA) and the British Association of Spinal Cord Injury Specialists (BASCIS) both recommend that transfer to a specialist SIU should be made as soon as possible after diagnosis of the spinal cord injury (Aung 1997, Carvell 1989, Carvell 1994, SIA 1997).

In the UK, referral of SCI patients to a local SIU usually takes place within a few weeks or months of injury. Accepted delays in transfer can be due to availability of spinal or ITU beds or physiological status. Transfer may also be delayed due to distance or mode of transport, or where patients present with significant accompanying trauma or respiratory compromise. However, a potentially significant number of people with SCI do not have the opportunity to access this system and are managed in a non‐specialist environment (commonly orthopaedic, neurosurgical or general rehabilitation areas) (Smith 1999).

A systematic review was commissioned by the UK's Health Technology Assessment Programme (Bagnall 2003) on the effectiveness and cost‐effectiveness of acute hospital‐based services for spinal cord injuries. The HTA review aimed to answer five research questions. One of those questions, "Does immediate referral to an SIU result in a better outcome than delayed referral?", is addressed in this review.