We performed an audit looking at the impact of NICE head injury guidelines published in June 2003¹ on the workload of the radiology department. This was performed retrospectively in the emergency department (ED) of Barnet District General Hospital over a three month period between 1 June and 31 August 2003. The hospital serves a population of about 250 000 and the ED sees 60 000 patients per annum.

Case notes were retrieved and electronic medical records were reviewed to determine whether the skull radiograph or CT scan of the head had been done using the existing guidelines for head injury and whether they would have been indicated if complying with the new NICE guidelines for head injury. The existing guidelines were as recommended by the Royal College of Radiologists.² It was also checked whether patients had CT scans of their head carried out subsequently at Barnet. “Head injury” for the purpose of audit was defined as any trauma to the head, other than superficial injuries to the face. Patients’ age, sex, time of arrival, day of arrival, Glasgow coma scale (GCS), risk factors, and disposal were noted.

A total of 16 008 patients attended the ED during the period reviewed. Altogether 520 (3.25%) attended with head injury. A total of 316 (61%) were male and 204 (39%) female. There were 39 (7%) infants, 105 (20%) between age of 1 and 5 years, 72 (14%) between age of 6 and 15 years, 222 (43%) between age of 16 and 64 years, and 82 (16%) between age of 65 and 97 years.

A total of 372 (72%) patients with head injury attended ED between Monday and Friday. Out of these 173 attended between 8 00 am and 5 00 pm and 199 between 5 00 pm and 8 00 am. A total of 148 (28%) patients with head injury attended on Saturday and Sunday. Out of these 61 attended between 8 00 am and 5 00 pm and 87 between 5 00 pm and 8 00 am.

Of 520 patients with head injury 59 (11.3%) patients had skull radiographs and 12 (2.3%) had CT scan of head done within existing head injury guidelines. Three patients had both CT scan and skull radiographs done. To comply with the new NICE guidelines for head injury no patient would have required skull radiography and 26 patients would have required CT scan of head including the 12 who had scan within existing guidelines (see table 1).

The study suggests that in a medium size semi-urban area district general hospital the number of CT scans of the head for head injury would increase from four to eight or nine a month. Most of these would not happen during normal working hours. This will increase the on-call workload by about two to three scans per month particularly as NICE expects them to be done within one hour of request for many indications. As skull radiographs are only indicated when CT is unavailable there would be a saving of about 20 skull radiographs per month.