. 2020 Jun 23;35:1533317520918719. doi: 10.1177/1533317520918719

Table 6.

Transition Intensities and Determinants of AD Stage Changes Using Functional and Cognitive Instruments Among the ADMDC Probable AD Cohort, Houston, Texas, 1990 to 2011.

	Transition Intensity/Transition Ratio^a	95% CI
MMSE (n = 972)
Base (transition intensity)
$exp ({\hat{β}}_{012})$	0.97	0.44-2.15
$exp ({\hat{β}}_{021})$	0.05	0.02-0.14
$exp ({\hat{β}}_{023})$	0.71	0.32-1.57
Transition ratio
Gender	1.08	0.92-1.28
Age, years	0.98	0.97-0.99
Education, years	1.01	0.98-1.03
Pre-progression	1.07	1.04-1.11
CDR-SB (n = 982)
Base transition intensity
$exp ({\hat{β}}_{012})$	0.34	0.15-0.74
$exp ({\hat{β}}_{021})$	0.03	0.01-0.08
$exp ({\hat{β}}_{023})$	0.24	0.11-0.54
Transition ratio
Gender	1.13	0.96-1.34
Age, years	0.99	0.98-1.00
Education, years	1.00	0.98-1.02
Pre-progression	1.08	1.05-1.11
ADAS-Cog (n = 847)
Base transition intensity
$exp ({\hat{β}}_{012})$	0.24	0.03-1.80
$exp ({\hat{β}}_{021})$	0.00	0.00-0.02
$exp ({\hat{β}}_{023})$	0.01	0.00-0.07
Transition intensity
Gender	1.05	0.73-1.51
Age, years	0.99	0.97-1.02
Education, years	1.03	0.97-1.09
Pre-progression	1.08	0.99-1.18

Abbreviations: AD, Alzheimer’s disease; ADAS-Cog, Alzheimer’s Disease Assessment Scale–Cognitive; ADMDC, Alzheimer’s Disease and Memory Disorders Center; CDR-SB, Clinical Dementia Rating Scale–Sum of Boxes; CI, confidence interval; MMSE: Mini-Mental State Examination.

^a Note that $e^{- {\hat{β}}_{r}} = 1 / e^{{\hat{β}}_{r}}$ is the multiplicative impact on mean duration. Transition ratio interpreted for gender as rate of transition for males relative to females. For other variables, the estimated ratio corresponds to a 1-unit incremental change.