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.
Survival curves for model 1 including only clinical covariates sex, age, MMSE score and APOE genotype. Three risk groups were defined corresponding to the lower, middle and upper thirds of subjects in the prognostic index (PI) distribution. With the low-risk group defined as reference, the hazard ratios are 3.4 [95% C.I.: 1.8–6.4, p < .001] and 4.9 [95% C.I.: 2.6–9.1, p < .001] for the medium- and high-risk group, respectively.
