Significant 2-way interaction of Trails A x Age with HgbA1C, indicating that Trails A predicts change in A1C over time.

## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: HgbA1C ~ LogTrailsA * cenAge + cenSex + cenRace + cenPovStat +  
##     cenEducnum + (cenAge | HNDid)
##    Data: Tasneem_1b
## Control: lmerControl(check.nobs.vs.nRE = "ignore")
## 
## REML criterion at convergence: 2893.1
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -3.3166 -0.4914 -0.1867  0.3468  5.6995 
## 
## Random effects:
##  Groups   Name        Variance Std.Dev. Corr 
##  HNDid    (Intercept) 2.100003 1.44914       
##           cenAge      0.001254 0.03542  -1.00
##  Residual             2.352845 1.53390       
## Number of obs: 687, groups:  HNDid, 345
## 
## Fixed effects:
##                    Estimate Std. Error        df t value Pr(>|t|)    
## (Intercept)         8.68053    0.85942 328.83490  10.100  < 2e-16 ***
## LogTrailsA         -0.45783    0.54829 330.81544  -0.835  0.40432    
## cenAge              0.18450    0.08475 524.38377   2.177  0.02992 *  
## cenSex              0.67565    0.20476 291.52716   3.300  0.00109 ** 
## cenRace             0.25691    0.20588 299.04994   1.248  0.21306    
## cenPovStat          0.26803    0.20978 298.28714   1.278  0.20237    
## cenEducnum         -0.05831    0.04102 292.88434  -1.422  0.15623    
## LogTrailsA:cenAge  -0.12471    0.05435 532.62751  -2.295  0.02214 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) LgTrlA cenAge cenSex cenRac cnPvSt cnEdcn
## LogTrailsA  -0.993                                          
## cenAge      -0.178  0.195                                   
## cenSex       0.136 -0.131  0.051                            
## cenRace      0.168 -0.169  0.040  0.121                     
## cenPovStat   0.104 -0.100  0.008  0.036 -0.009              
## cenEducnum  -0.160  0.161 -0.087 -0.022 -0.110  0.179       
## LgTrlsA:cnA  0.196 -0.217 -0.992 -0.042 -0.046  0.006  0.089

This one is a little weird…Plotting the interaction effect shows that slower Trails A performance at baseline is associated with the declining HgbA1C over time, whereas faster Trails A performance is associated with rising A1C. I’ll do a little more probing of this effect.

Next, we have a significant 3-way interaction of CES x EF (composite) x Age with HgbA1C, indicating that the CES and EF interact to predict change in glucose over time

## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: HgbA1C ~ CES * EF * cenAge + cenSex + cenRace + cenPovStat +  
##     cenEducnum + (cenAge | HNDid)
##    Data: Tasneem_1b
## Control: lmerControl(check.nobs.vs.nRE = "ignore")
## 
## REML criterion at convergence: 2908.1
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -3.3143 -0.4968 -0.1811  0.3516  5.6816 
## 
## Random effects:
##  Groups   Name        Variance Std.Dev. Corr 
##  HNDid    (Intercept) 2.130678 1.45968       
##           cenAge      0.001859 0.04312  -0.75
##  Residual             2.290015 1.51328       
## Number of obs: 680, groups:  HNDid, 341
## 
## Fixed effects:
##                 Estimate Std. Error         df t value Pr(>|t|)    
## (Intercept)    7.667e+00  1.894e-01  3.078e+02  40.492  < 2e-16 ***
## CES            1.757e-02  1.079e-02  3.115e+02   1.629  0.10442    
## EF             4.610e-02  9.166e-02  2.833e+02   0.503  0.61534    
## cenAge         3.679e-03  1.931e-02  1.361e+02   0.191  0.84919    
## cenSex         6.839e-01  2.069e-01  2.651e+02   3.305  0.00108 ** 
## cenRace        3.059e-01  2.184e-01  2.797e+02   1.401  0.16236    
## cenPovStat     2.159e-01  2.166e-01  2.834e+02   0.997  0.31971    
## cenEducnum    -5.076e-02  4.472e-02  2.872e+02  -1.135  0.25734    
## CES:EF         7.924e-04  4.872e-03  2.920e+02   0.163  0.87091    
## CES:cenAge    -9.578e-04  1.092e-03  1.309e+02  -0.877  0.38217    
## EF:cenAge      1.220e-02  8.622e-03  1.213e+02   1.415  0.15951    
## CES:EF:cenAge -1.060e-03  4.825e-04  1.343e+02  -2.198  0.02968 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) CES    EF     cenAge cenSex cenRac cnPvSt cnEdcn CES:EF
## CES         -0.823                                                        
## EF          -0.043 -0.038                                                 
## cenAge      -0.276  0.177  0.249                                          
## cenSex      -0.019  0.063 -0.059  0.037                                   
## cenRace     -0.059  0.100  0.143 -0.028  0.095                            
## cenPovStat   0.137 -0.127  0.058  0.087  0.023 -0.003                     
## cenEducnum  -0.131  0.133 -0.221 -0.033  0.012 -0.172  0.107              
## CES:EF      -0.015  0.173 -0.788 -0.176  0.082  0.065  0.011  0.008       
## CES:cenAge   0.180 -0.111 -0.180 -0.810 -0.014  0.037 -0.044  0.035  0.183
## EF:cenAge    0.248 -0.183 -0.211 -0.155  0.035  0.032 -0.004 -0.081  0.140
## CES:EF:cnAg -0.187  0.187  0.121  0.068 -0.034 -0.024 -0.023  0.056 -0.067
##             CES:cA EF:cnA
## CES                      
## EF                       
## cenAge                   
## cenSex                   
## cenRace                  
## cenPovStat               
## cenEducnum               
## CES:EF                   
## CES:cenAge               
## EF:cenAge    0.062       
## CES:EF:cnAg  0.069 -0.828
##     Min.  1st Qu.   Median     Mean  3rd Qu.     Max.     NA's 
## -5.25085 -1.64835 -0.05227 -0.15709  1.27476  6.00450       76
## [1] 2.16346
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.    NA's 
##    0.00    6.00   13.00   14.91   22.00   46.00      46
## [1] 10.4319

This one is also weird. The following three graphs represent age-related change in A1C at low, average, and high levels of EF, with the graphs split at different levels of depression.

  1. Low Depression

  2. Mean Depression

  3. High Depression

Next, we have a 3-way interaction of CES x Depression x Verbal Fluency with A1C

## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: 
## HgbA1C ~ CES * FluencyWord * cenAge + cenSex + cenRace + cenPovStat +  
##     cenEducnum + (cenAge | HNDid)
##    Data: Tasneem_1b
## Control: lmerControl(check.nobs.vs.nRE = "ignore")
## 
## REML criterion at convergence: 2998.6
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -3.3192 -0.5038 -0.1953  0.3490  5.7415 
## 
## Random effects:
##  Groups   Name        Variance Std.Dev. Corr 
##  HNDid    (Intercept) 2.145611 1.46479       
##           cenAge      0.001415 0.03761  -0.93
##  Residual             2.287940 1.51259       
## Number of obs: 701, groups:  HNDid, 351
## 
## Fixed effects:
##                          Estimate Std. Error         df t value Pr(>|t|)
## (Intercept)             7.919e+00  6.857e-01  3.049e+02  11.549  < 2e-16
## CES                    -7.398e-03  3.681e-02  3.215e+02  -0.201  0.84087
## FluencyWord            -1.691e-02  3.475e-02  2.835e+02  -0.486  0.62702
## cenAge                 -1.061e-01  6.679e-02  1.609e+02  -1.589  0.11411
## cenSex                  6.264e-01  2.022e-01  2.702e+02   3.098  0.00216
## cenRace                 2.038e-01  2.043e-01  2.838e+02   0.997  0.31950
## cenPovStat              1.266e-01  2.109e-01  2.938e+02   0.600  0.54892
## cenEducnum             -2.758e-02  4.253e-02  2.944e+02  -0.648  0.51726
## CES:FluencyWord         1.461e-03  1.933e-03  3.052e+02   0.756  0.45038
## CES:cenAge              6.957e-03  3.931e-03  2.292e+02   1.770  0.07808
## FluencyWord:cenAge      5.714e-03  3.263e-03  1.495e+02   1.751  0.08203
## CES:FluencyWord:cenAge -4.016e-04  2.004e-04  2.160e+02  -2.004  0.04632
##                           
## (Intercept)            ***
## CES                       
## FluencyWord               
## cenAge                    
## cenSex                 ** 
## cenRace                   
## cenPovStat                
## cenEducnum                
## CES:FluencyWord           
## CES:cenAge             .  
## FluencyWord:cenAge     .  
## CES:FluencyWord:cenAge *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) CES    FlncyW cenAge cenSex cenRac cnPvSt cnEdcn
## CES         -0.832                                                 
## FluencyWord -0.964  0.806                                          
## cenAge      -0.304  0.230  0.244                                   
## cenSex       0.079 -0.044 -0.089 -0.030                            
## cenRace     -0.102  0.038  0.090 -0.058  0.066                     
## cenPovStat   0.052 -0.036 -0.017  0.006  0.023 -0.047              
## cenEducnum   0.137  0.004 -0.182  0.040  0.036 -0.100  0.164       
## CES:FlncyWr  0.786 -0.960 -0.823 -0.178  0.059 -0.019 -0.005  0.044
## CES:cenAge   0.212 -0.175 -0.168 -0.828  0.052  0.082  0.056 -0.014
## FlncyWrd:cA  0.251 -0.191 -0.207 -0.962  0.045  0.047  0.014 -0.050
## CES:FlncW:A -0.168  0.133  0.135  0.778 -0.061 -0.077 -0.069  0.026
##             CES:FlW CES:cA FlnW:A
## CES                              
## FluencyWord                      
## cenAge                           
## cenSex                           
## cenRace                          
## cenPovStat                       
## cenEducnum                       
## CES:FlncyWr                      
## CES:cenAge   0.126               
## FlncyWrd:cA  0.151   0.809       
## CES:FlncW:A -0.094  -0.964 -0.818
## fit warnings:
## Some predictor variables are on very different scales: consider rescaling

Plots split by level of depression:

  1. Low depression

  2. Mean Depression

  3. High Depression

Finally, there was a significant 3-way interaction of CES x EF (composite) x Age on Glucose

## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: Glucose ~ CES * EF * cenAge + cenSex + cenRace + cenPovStat +  
##     cenEducnum + (cenAge | HNDid)
##    Data: Tasneem_1b
## Control: lmerControl(check.nobs.vs.nRE = "ignore")
## 
## REML criterion at convergence: 7752.4
## 
## Scaled residuals: 
##     Min      1Q  Median      3Q     Max 
## -2.5437 -0.4867 -0.1716  0.3046  3.6979 
## 
## Random effects:
##  Groups   Name        Variance Std.Dev. Corr 
##  HNDid    (Intercept) 2119.345 46.036        
##           cenAge         1.912  1.383   -0.91
##  Residual             3478.933 58.982        
## Number of obs: 683, groups:  HNDid, 343
## 
## Fixed effects:
##                Estimate Std. Error        df t value Pr(>|t|)    
## (Intercept)   155.93877    6.49157 298.90219  24.022  < 2e-16 ***
## CES             0.46313    0.37007 305.13179   1.251 0.211723    
## EF              1.51617    3.12145 299.18046   0.486 0.627518    
## cenAge         -0.08610    0.68028 163.06403  -0.127 0.899438    
## cenSex         27.01572    7.06619 258.76074   3.823 0.000165 ***
## cenRace       -10.65947    7.46644 269.41856  -1.428 0.154550    
## cenPovStat      8.21437    7.40291 275.95139   1.110 0.268131    
## cenEducnum     -1.67701    1.53268 278.88815  -1.094 0.274826    
## CES:EF          0.05477    0.16619 299.11730   0.330 0.741973    
## CES:cenAge     -0.06334    0.03838 157.68194  -1.650 0.100851    
## EF:cenAge       0.14859    0.30143 146.79076   0.493 0.622776    
## CES:EF:cenAge  -0.03456    0.01688 163.33734  -2.047 0.042280 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Correlation of Fixed Effects:
##             (Intr) CES    EF     cenAge cenSex cenRac cnPvSt cnEdcn CES:EF
## CES         -0.823                                                        
## EF          -0.062 -0.025                                                 
## cenAge      -0.295  0.192  0.255                                          
## cenSex      -0.018  0.063 -0.065  0.038                                   
## cenRace     -0.059  0.099  0.144 -0.035  0.095                            
## cenPovStat   0.137 -0.133  0.061  0.092  0.026 -0.005                     
## cenEducnum  -0.131  0.133 -0.215 -0.034  0.008 -0.175  0.110              
## CES:EF      -0.002  0.163 -0.789 -0.179  0.086  0.066  0.004  0.002       
## CES:cenAge   0.195 -0.128 -0.182 -0.811 -0.012  0.043 -0.052  0.036  0.178
## EF:cenAge    0.254 -0.186 -0.225 -0.159  0.037  0.030 -0.006 -0.084  0.153
## CES:EF:cnAg -0.190  0.184  0.133  0.072 -0.035 -0.020 -0.028  0.059 -0.086
##             CES:cA EF:cnA
## CES                      
## EF                       
## cenAge                   
## cenSex                   
## cenRace                  
## cenPovStat               
## cenEducnum               
## CES:EF                   
## CES:cenAge               
## EF:cenAge    0.067       
## CES:EF:cnAg  0.059 -0.829

Plots split by level of depression:

  1. Low Depression

  2. Mean Depression

  3. High Depression