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Table 3 Comparison of model outputs by retest correction method

From: Correction for retest effects across repeated measures of cognitive functioning: a longitudinal cohort study of postoperative delirium

 

Model 1: No Correction

Model 2: Mean Difference Correction

Model 3: Predicted Difference Correction

Model 4: Model-based Correction

Model Parameter

Del-

Del+

Net Diff.

Del-

Del+

Net Diff.

Del-

Del+

Net Diff.

NSC

Del-

Del+

Net Diff.

Intercept

58.32

(0.31)

55.33

(0.55)

−3.00*

(0.63)

58.32

(0.31)

55.33

(0.55)

− 3.00*

(0.63)

58.31

(0.32)

55.35

(0.57)

−2.97*

(0.65)

57.86

(0.61)

58.32

(0.31)

55.41

(0.56)

−2.91*

(0.64)

Change at month 1

1.08

(0.16)

−0.20

(0.28)

−1.28*

(0.32)

−0.73

(0.16)

−2.01

(0.28)

−1.28*

(0.32)

−0.67

(0.16)

−2.27

(0.28)

−1.60*

(0.32)

1.80

(0.29)

1.08

(0.15)

−0.20

(0.28)

−1.28*

(0.31)

Change at month 2

1.39

(0.14)

2.33

(0.26)

0.94*

(0.29)

1.08

(0.14)

2.02

(0.26)

0.94*

(0.29)

1.04

(0.14)

2.17

(0.26)

1.14*

(0.29)

0.32

(0.27)

1.39

(0.14)

2.33 (0.25)

0.94*

(0.29)

Change from months 2–18

0.23

(0.12)

−0.11

(0.22)

− 0.34

(0.25)

0.40

(0.12)

0.06

(0.22)

−0.34

(0.25)

0.39

(0.12)

0.07

(0.22)

−0.32

(0.25)

−0.10

(0.27)

0.23

(0.12)

−0.11

(0.22)

− 0.34

(0.25)

Model R2 by group

0.32

0.27

 

0.31

0.25

 

0.31

0.25

 

0.47

0.32

0.27

 

Model R2

0.35

0.33

0.33

0.37

  1. Comparison of model outputs for baseline GCP (intercept), change in GCP from baseline to 1 month, change in GCP from month 1 to 2, and estimated GCP slope from 2 to 18 months by retest correction method. Model outputs are presented as parameter estimates (and standard errors) for intercept, time indicator variables at months 1 and 2, and time-slope from months 2–18 by group for each retest correction method
  2. Del- = surgery Delirium-negative group (n = 426), Del + = surgery delirium-positive group (n = 134), NSC = non-surgical comparison group (n = 118). GCP = General Cognitive Performance. For models 1–3, Del- is the reference group; for model 4, NSC is the reference group. Net diff = net difference calculated as the β-coefficient in the surgery delirium- group subtracted from the β-coefficient in the surgery delirium+ group. R2 is the squared correlations of observed and model-implied outcome values
  3. *Indicates a significant difference between delirium groups at α = 0.05