Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Mean age of symptom onset in female patients with Alzheimer disease with and without risk factors apolipoprotein E-ε4 and history of traumatic brain injury. Bars represent 95% confidence intervals for each group. TBI = traumatic brain injury with loss of consciousness. Apoe4 = apolipoprotein E-e4 allele.
