Figure 4.

Sample predictions from the model of Eqn. (3) and Table 2 to illustrate the trajectory of Cambridge Cognition Examination (CAMCOG) in hypothetical individuals with characteristics that are typical for the data set used in the analysis. (a) women; (b) men, both without APOEε4 allele. Four different scenarios are depicted for each of two starting values of CAMCOG score: high and low. The scenarios are as follows: no diagnoses (mild cognitive impairment or possible or probable Alzheimer's dementia), black lines; diagnoses made at 2.5 years, red lines; no surgery is indicated by dashes; a single episode of surgery at 3 years is indicated by solid lines. Initial CAMCOG scores are 98 and 85 for womens; the (lower) male initial CAMCOG values are those for all variables being identical other than gender.