Objectives The aim of our project was to illustrate the effects that recent NICE head injury and stroke guidelines have had on the role of emergency intracranial imaging in patients older than 75 years and identify the reasons for this.

Method We looked at the number of CT head scans performed in patients over the age of 75 years in the emergency department during the course of a month in 2013 (before the NICE head injury guidelines were updated) and compared this with those performed during a comparable time period in 2018. We analysed the number, the indications and compared these with those outlined in the NICE head injury, NICE and RCP stroke guidelines.

Results During June 2013, 22 patients over 75 years were scanned compared with 139 in March 2018. Head injury (45% in 2013, 57% in 2018) followed by stroke (36% vs 29%) and other (headache, collapse, confusion) (14% vs 18%) were listed as indications, however the proportion of positive findings reduced in 2018 from 41% to 11% (9 to 11 patients). 54% of those performed for head injury in 2018 strictly complied with head injury guidelines. These guidelines are however open to interpretation, for example, although imaging for patients on NOACs is not explicitly advised, it is for bleeding disorders. On analysis of clinical information provided, multiple risk factors identified in each of these guidelines, were often listed as indications for intracranial imaging, rather than differential diagnoses. Incidental findings increased in 2018 (4%) and a number of patients underwent multiple CT scans in the preceeding 3–6 months for the same indication (2%).

Conclusions Guidelines have reduced the threshold for imaging elderly patients and encouraged a shift towards investigation based on risk factors rather than individual circumstances. This unsurpisingly, has resulted in over investigation of elderly patients in particular, who often have multiple comorbidities and are subsequently at higher risk. Additionally, the increasing porportion of elderly patients in the population and seeking urgent care are factors to be considered. The only way investigations can be rationalised is through better assessment of elderly patients (a view that is shared by the Royal College of Emergency Medicine). This is difficult, especially against a background of defensive medical practice. However, even the smallest improvement can have significant cost saving implications, and so by increasing awareness we hope to shift the focus back to choosing the right investigations at the right time for the right patient, as surely this is ultimately in the patient’s best interests?