Figure 3. Conversion from MCI to dementia as predicted by baseline CSF biomarkers.

(a) MCI survival based on the minimal Cox proportional hazards model (Table 2), the conversion is plotted for each quintile of ferritin (applying mean values for the cohort: ApoE=7.2 μg ml⁻¹, tau/Aβ_1–42=0.69 units). The numbers on the right side of the graphs indicate the quintile boundaries. This minimal model contained only the CSF biomarkers. (b) Change in mean age of diagnosis according to CSF biomarkers. The months taken for ∼50% survival of each quintile boundary in the Cox models were graphed against the unit values of those boundaries. The gradient of the linear model was used to estimate change in age of conversion for each unit change in analyte. (refer to Fig. 3a, Supplementary Fig. 4). (c–e) Receiver operating curves of logistic regression modelling of MCI conversion to AD (refer to Table 2, Supplementary Fig. 5). (c) Base model controlling for age, gender, BMI, years of education and APOE ɛ4 status. (d) Base model plus ApoE and tau/Aβ_1-42. (e) Base model plus ApoE, tau/Aβ_1–42 and ferritin. AUC, area under curve.