BACKGROUND: The Canadian CT Head Rule (CCTHR) is validated in adults who hit their head and experience loss of consciousness, amnesia, or disorientation. There is less evidence to guide brain imaging when the fall history is unclear.
METHODS: This is a secondary analysis of a prospective study on adults aged ≥ 65 who presented to 11 emergency departments across Canada and the United States after a ground level fall. We reported the prevalence of adjudicated clinically important intracranial bleeding within 42 days of the emergency department visit among (a) patients who hit their head and met the application criteria for the CCTHR (experienced loss of consciousness, amnesia, or disorientation), (b) patients who hit their head and did not meet the CCTHR application criteria, (c) patients with an unclear history of the CCTHR application criteria, (d) patients with an unclear head injury history, and (e) patients with no head injury.
RESULTS: 4303 participants were analyzed. The prevalence of clinically important intracranial bleeding in the subgroups was (a) patients who fulfilled the CCTHR application criteria, 7.7% (54/703, 95% confidence interval [CI]: 5.9%-9.9%), (b) patients who hit their head but did not meet CCTHR application criteria, 2.5% (30/1204, 95% CI: 1.8%-3.5%), (c) patients with head injury but an unclear history of the CCTHR application criteria, 7.6% (19/251, 95% CI: 4.9%-12.0%), (d) patients with an unclear history of head injury, 4.6% (23/502, 95% CI: 3.2%-6.8%), and (e) patients who did not hit their head, 0.8% (13/1643, 95% CI: 0.5%-1.3%).
CONCLUSIONS: Older adults presenting after a fall with an unclear history of head injury, or an unclear history of head injury-associated loss of consciousness, amnesia, or disorientation have an elevated risk for clinically important intracranial bleeding that merits emergency brain imaging.