. Author manuscript; available in PMC: 2019 Mar 1.

Published in final edited form as: Stat Methods Med Res. 2016 Apr 28;27(3):863–875. doi: 10.1177/0962280216645632

Table 3.

Results from sigmoidal modeling on global cognition

Parameters	Estimate	Standard Error	Pr > \|t\|
Initial level
α₄	0.587	0.057	<.0001
Education	0.018	0.009	0.045
Age at baseline	−0.016	0.005	0.000
BMI at baseline	0.002	0.005	0.725
Decline midpoint
α ₂	−1.402	0.172	<.0001
Education	0.001	0.027	0.981
Age at baseline	0.169	0.029	<.0001
Age at death	−0.216	0.025	<.0001
Range of BMI	−0.265	0.048	<.0001
Rate of decline
α ₃	0.830	0.091	<.0001
Education	0.027	0.009	0.003
Age at baseline	−0.033	0.009	0.001
Age at death	0.067	0.010	<.0001
Range of BMI	0.037	0.014	0.009
Level at death
α ₁	−0.902	0.092	<.0001
Education	0.016	0.022	0.465
Age at death	−0.037	0.012	0.003
Last BMI before death	−0.016	0.014	0.237
Variance and covariance
Error	0.246	0.003	<.0001
u	2.120	0.227	<.0001
v	0.174	0.034	<.0001
u,v	−0.284	0.100	0.005

Education represents years of formal education centered at 17 years. Age at baseline and at death is centered respectively at 79 and 89 years. BMI at baseline and the last before death were centered at 26.