Anesthesia and Age - Full Dataset - Final Analysis - UW and HMC

## This is gamm4 0.2-1

Table 1 : descriptive statistics for predictor variables by hospital and COHORT

                          Variable   UWMC.Cohort.1   UWMC.Cohort.2

                   Number of Cases            4659            5030

                               Age                                
                         Mean (SD)    50.67 (16.3)   51.93 (16.29)

                            Gender                                
                            % Male           44.92           44.83

                               BIS                                
                      BIS USED (%)           35.76           35.21

                           ASA (%)                                
                               1/2           59.41           58.33
                                 3            37.6           37.36
                                 4            2.98            4.31

                         EMERGENCY                                
                     EMERGENCY (%)            4.19            3.94

          Inpatient vs. Outpatient                                
                       % Inpatient           41.68           39.78

      Maintenance Duration (Hours)                                
                         Mean (SD)     0.64 (0.56)     0.66 (0.59)

       Inhalational Agent Used (%)                                
                               sev           68.94           87.95
                               iso            2.43             3.5
                               des           28.63            8.55

           MIDAZOLAM PREMEDICATION                                
       MIDAZOLAM PREMEDICATION (%)           69.84           67.91

        Fentanyl During Case (mcg)                                
                         Mean (SD) 197.79 (121.41) 196.03 (113.49)

 PARALYTIC REDOSE AFTER INTUBATION                                
              PARALYTIC REDOSE (%)           54.02           40.08

  BUPIVICAINE INFUSION DURING CASE                                
          BUPIVICAINE INFUSION (%)            1.67            3.52

Table 2 : Bivariate statistics for relationship between predictors and aaMAC

The p values here are based on the bivariate anova : if there's any non-zero different in mean across categories, the p value will be significant. In other words, it's not a particularly conservative test.

In sum : we're looking for variables that appear to correlate with aaMAC, in each site and over time.

                     Variable UWMC.1.aaMAC       p UWMC.2.aaMAC     p.1

                 Age Category                                          
                      (17,54]       0.9136       0       0.8725       0
                      (54,65]        0.999               0.9375        
                      (65,75]       1.0126               0.9609        
                      (75,85]       0.9953               0.9737        
                     (85,150]       0.9879                0.945        

                       Gender                                          
                       Female       0.9356       0       0.8997   2e-04
                         Male       0.9723               0.9194        

                          BIS                                          
                 BIS not used       0.9566 0.03455       0.9108 0.23503
                     BIS used        0.944               0.9043        

                          ASA                                          
                            1        0.953 0.07571       0.9087 0.14498
                            3       0.9618               0.9186        
                            4       0.8121               0.8188        

                ASA EMERGENCY                                          
                           No       0.9555       0       0.9116       0
                          Yes       0.8727               0.8341        

                 Patient Type                                          
                    Inpatient       0.9634 0.00077       0.9217   5e-05
                   Outpatient        0.944               0.8998        

 Maintenance Duration (hours)                                          
                 [0.05,0.267]       0.9195       0       0.8818       0
                  (0.267,0.5]       0.9486               0.8869        
                   (0.5,0.85]       0.9776               0.9231        
                  (0.85,4.58]       0.9677               0.9448        

           Inhalational Agent                                          
                          sev       0.9351       0        0.901       0
                          iso       0.8439               0.8614        
                          des       1.0022               1.0047        

      Midazolam Premedication                                          
                           No       0.9553 0.45554        0.915 0.08924
                          Yes       0.9507               0.9054        

         Total Fentanyl (mcg)                                          
                      [0,100]       0.9023       0       0.8508       0
                    (100,200]        0.957               0.9117        
                    (200,250]       0.9781               0.9425        
               (250,2.25e+03]       0.9806               0.9458        

             Paralytic Redose                                          
                           No       0.9587 0.03273        0.901 0.00053
                          Yes       0.9465               0.9197        

           Regional/Neuraxial                                          
                           No       0.9535 0.00016       0.9083 0.64065
                          Yes       0.8695                0.915        

Figure 1 : Multivariate Linear Models, all Coefficients

Default categoricals : Inpatient, Sevoflurane, ASA = 1

Note : fentanyl reparameterized to fentanyl / 50 to make interpretation of coefficient easier

                           VAR      EST     LO95     HI95      P COHORT
 friendlySplines(DECADE, 6.5)1   4.9073   4.3056   5.5089 0.0000   2010
 friendlySplines(DECADE, 6.5)2  -0.8597  -2.6584   0.9390 0.3489   2010
                        ANYBIS  -3.9842  -5.5119  -2.4565 0.0000   2010
                          MALE   3.0416   1.8432   4.2401 0.0000   2010
          MAINTENANCE_DURATION   0.4935  -0.9504   1.9374 0.5029   2010
                     PT.CLASSO  -2.2250  -3.6331  -0.8168 0.0020   2010
              factor(ASA.new)3  -4.6037  -6.1544  -3.0529 0.0000   2010
              factor(ASA.new)4 -19.0376 -23.8196 -14.2556 0.0000   2010
                     EMERGENCY  -5.7716  -9.2754  -2.2678 0.0012   2010
                  MAINAGENTiso -10.6830 -15.4386  -5.9275 0.0000   2010
                  MAINAGENTdes   6.5435   5.1130   7.9740 0.0000   2010
                  MIDAZ_PREMED   1.2833  -0.3748   2.9414 0.1293   2010
           PARALYTIC_REDOSEYes  -2.4585  -3.8564  -1.0606 0.0006   2010
                    FENTANYL50   1.2365   0.6958   1.7773 0.0000   2010
                   ANY_BUPIYes  -6.9036 -11.0075  -2.7997 0.0010   2010
                           VAR      EST     LO95     HI95      P COHORT
 friendlySplines(DECADE, 6.5)1   3.9449   3.4274   4.4624 0.0000   2012
 friendlySplines(DECADE, 6.5)2   2.0908   0.5353   3.6462 0.0084   2012
                        ANYBIS  -1.9993  -3.2313  -0.7673 0.0015   2012
                          MALE   1.9614   0.7935   3.1293 0.0010   2012
          MAINTENANCE_DURATION   0.5618  -0.9236   2.0472 0.4585   2012
                     PT.CLASSO  -0.5283  -1.9732   0.9166 0.4736   2012
              factor(ASA.new)3  -3.4778  -4.7944  -2.1612 0.0000   2012
              factor(ASA.new)4 -16.7245 -21.5749 -11.8741 0.0000   2012
                     EMERGENCY  -7.7788 -12.8036  -2.7540 0.0024   2012
                  MAINAGENTiso  -8.2744 -12.4480  -4.1008 0.0001   2012
                  MAINAGENTdes  10.7609   9.0155  12.5064 0.0000   2012
                  MIDAZ_PREMED   1.0102  -0.4467   2.4670 0.1741   2012
           PARALYTIC_REDOSEYes  -0.3509  -1.7531   1.0513 0.6238   2012
                    FENTANYL50   1.9385   1.5905   2.2865 0.0000   2012
                   ANY_BUPIYes  -2.9479  -6.0127   0.1169 0.0594   2012

plot of chunk figure1

Figure 2 : GLM

plot of chunk figure_2

Figure 3

Vasopressors

plot of chunk pred_aamac_vs_vasopressors

Figure 3

This figure repesents the relationship between measured aaMAC and the mean BIS during maintenance phase of anesthesia (though perhaps median would be preferable, given our use of that population parameter in the rest of our study. Only 66 patients had BIS at HMC during ths study period, and therefore the plot is limited just to cases with BIS at UWMC.

plot of chunk pred_aamac_vs_avgbis