As a neurologist and emergency physician, we see many patients with minor head injuries at the emergency department. We know that one or two in a hundred may have what is often called a “doctor’s nightmare”—a subdural or epidural hematoma that manifests itself with coma and sometimes death after the patient has been sent home. We therefore screen patients for risk factors of intracranial complications and follow clinical guidelines to help decide if a head computed tomography (CT) is necessary or not. In the last couple of years the incidence of patients with minor head injury has increased. In order to prevent long waiting times and overcrowding at the emergency departments an adequate decision rule or clinical guideline for head CT is now more important than ever.
Our national and local guidelines in the Netherlands are based on the CT in Head Injury Patients (CHIP) prediction rule which was developed in 2007 to identify all patients with serious lesions and to reduce the number of head CTs. However, to determine the generalisability of the rule in patient cohorts other than the development cohort, we needed an external validation study.
Therefore, in 2015 we decided to start a prospective multicentre validation study in nine emergency departments throughout the Netherlands. Three of the centres were university hospitals and six were non-university hospitals. Five were level 1 regional trauma centres. We compared decision rules and guidelines for minor head injury, including the CHIP rule and the National Institute for Clinical Excellence (NICE) guideline for head injury.
The collaboration between all nine participating centres was well established and in a period of two years we included about 5500 patients with minor head injury and analysed all their risk factors and head CT results. Because of the high number of patients it was challenging to collect all the clinical information and store it in our web-based database. We were lucky that we could take advantage from the fact that several centres participated in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. This study was also focused on patients with traumatic head injury and the same researcher physicians collected the data for our study
Our study published in The BMJ shows that application of different guidelines led to a variation of unnecessary head CTs and some missed traumatic findings.
Because the CHIP rule missed only a few potential serious lesions and led to a substantial reduction of head CTs, we believe an update of this rule is the next necessary step in research. Currently we are performing this update and we hope to publish the results in the near future.
Competing interests: None declared.