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Table 1 Relationship between pre-progression category and subsequent rate of decline on cognitive and functional measures

From: Predicting progression of Alzheimer's disease

  Progression measures
Independent Variables¶ ADAS-Cog
(n = 552)
VSAT Time
(n = 589)
VSAT Errors
(n = 589)
CDR-SB
(n = 596)
IADL
(n = 573)
PSMS
(n = 575)
  Beta P Beta P Beta P Beta P Beta P Beta P
Duration of Symptoms 1.352 <.001 7.405 <.001 -0.778 <.001 0.446 <.001 0.523 <.001 0.243 .015
Baseline Severity (mild vs. moderate/severe) -10.052 <001 -61.158 <001 -7.886 <.001 -3.088 <.001 -3.204 <.001 -2.129 <.001
Years of Follow-up 3.323 <.001 20.335 <.001 3.033 <.001 2.084 <.001 3.309 <.001 2.430 <.001
Years of Follow-up Squared 0.514 .036 -- NS -- NS -- NS -0.207 .003 -- NS
Pre-progression Rate             
Intermediate vs. Fast -4.032 .006 -20.351 .033 -3.046 .007 -1.399 .003 -1.915 .012 -0.442 .424
Slow vs. Fast -9.458 <.001 -49.417 <.001 -6.533 <.001 -2.593 <.001 -3.051 .001 -0.454 .520
Linear Interaction 1* -- NS -- NS -- NS 0.247 .039 -- NS -- NS
Linear Interaction 2* -- NS -- NS -- NS -- NS -- NS -1.133 <.001
Non-linear Interaction1* -0.807 .004 -- NS -- NS -- NS -- NS -- NS
Non-linear Interaction 2* -0.554 .039 -- NS -- NS -- NS -- NS -- NS
Model Intercept 56.601   617.164   62.203   10.364   14.96   4.243  
  1. * Interaction 1 = time by intermediate pre-progression group (fast = reference group); Interaction 2 = time by slow pre-progression group (fast = reference); Non-linear Interaction 1 = time squared by intermediate pre-progression group (fast = reference group); Non-linear interaction 2 = Time squared by slow pre-progression group (fast = reference group).
  2. Models adjusted for age at diagnosis, sex, years of education, duration of symptoms at diagnosis, baseline severity (categorical), pre-morbid IQ, and presence of hallucinations and/or delusions. If the quadratic term for follow-up time and the pre-progression group by quadratic time variable were not significant, coefficients for models with linear terms only are shown. Non-significant (NS) betas for interaction terms omitted from table.
  3. ADAS-cog = Alzheimer's disease Assessment Scale-cognitive subscale; CDR-SB = Clinical Dementia Rating Scale Sum of Boxes; IADL = Instrumental Activities of Daily Living scale; PSMS = Physical Self-Maintenance Scale; VSAT = Verbal Series Attention Test.