When correcting for measurement error (κ1; κ2) at both time points, the heritability of LTH-AD was estimated to be 71% (λa2); whereas individual specific environment accounted for the remaining 29% (λe2) (Fig. 1B). When error of measurement at both time points was included in the individual specific environmental factor, the heritability of LTH-AD assessed at both time points was reduced to 55%. The square of the pathways between the latent factor and the observed measurements (λ1; λ2), estimated to be 0.77, gives an indication of the reliability of LTH-AD.
