Prospective evaluation of selected clinical criteria for cranial computed tomography in non‐trauma adult patients

Objective: To evaluate the usefulness of previously published criteria by Rothrock et al. and Harris et al. for urgent, cranial CT in non‐trauma presentations. Methods: A prospective, observational study of consecutive adult patients with non‐trauma presentations to Westmead Emergency Department, undergoing urgent cranial CT over a period of 2 years and 10 months. Clinical data were assessed to determine the presence of the proposed Rothrock and Harris criteria. Clinically significant findings defined by CT were intracerebral haemorrhage, acute infarction, intracranial infection, acute hydrocephalus, cerebral oedema and malignancy. Results: A total of 1911 patients were studied. Among them, 21.7% (414/1911) of patients had clinically significant findings on CT. Application of the Harris criteria demonstrated a sensitivity of 93.5% (387/414, 95% CI 90.7–95.7) and a false negative rate of 6.5% (27/414, 95% CI 4.3–9.3) with a potential reduction in number of scans by 27.8%. With application of the Rothrock criteria, the possible scan reduction rate was 15% with a sensitivity of 98.8% (409/414, 95% CI 97.2–99.6) and a false negative rate of 1.2% (5/414, 95% CI 0.4–2.8). Conclusion: The Harris criteria were not validated by our study. The Rothrock criteria are also not confidently validated, but can be a useful guide for emergency physicians to help prioritize high‐risk patients who might have clinically significant cranial CT findings. We have not replicated their very high sensitivity and very low false negative rates.