Neurosurgical resources and transfer policies for head injuries.

Criteria for transferring head injured patients to a regional neurosurgical unit were changed to enable a larger proportion of patients admitted to primary surgical wards to have a CT scan. The yearly number of transfers doubled, more intracranial haematomas were detected, and mortality from this complication was reduced. To operate such a policy requires seven neurosurgical beds per million for head injuries, given the Glasgow practice of early return of patients to primary surgical wards.