Table 3

Unadjusted and adjusted linear models looking at factors impacting costs

FactorUnadjustedAdjusted
Effect estimate
(95% CI)		P valueEffect estimate
(95% CI)		P value
Total cost
 Group*0.98 (0.97 to 0.99)<0.001†0.98 (0.97 to 0.99)<0.001
 Robotic‡1.02 (1.01 to 1.03)<0.001†1.02 (1.00 to 1.03)<0.007†
 Charlson Comorbidity moderate and higher§1.00 (0.98 to 1.01)0.793
 Charlson Comorbidity mild§0.99 (0.97 to 1.01)0.238
 BMI1.00 (1.00 to 1.00)0.061
 Age1.00 (1.00 to 1.00)0.511
OR cost
 Group*0.92 (0.86 to 0.98)0.007†0.99 (0.96 to 1.01)0.303
 Robotic‡1.61 (1.57 to 1.65)<0.001†1.60 (1.56 to 1.65)<0.001†
 Charlson Comorbidity moderate and higher§1.00 (0.90 to 1.10)0.977
 Charlson Comorbidity mild§0.98 (0.88 to 1.09)0.719
 BMI1.01 (1.01 to 1.02)<0.001†1.00 (1.00 to 1.00)0.591
 Age1.00 (1.00 to 1.00)0.511
Post-operative stay cost
 Group*0.85 (0.79 to 0.91)<0.001†0.87 (0.81 to 0.93)<0.001†
 Robotic‡1.15 (1.05 to 1.25)0.002†1.12 (1.03 to 1.22)0.007†
 Charlson Comorbidity moderate and higher§0.98 (0.87 to 1.10)0.754
 Charlson Comorbidity mild§0.92 (0.81 to 1.05)0.214
 BMI1.00 (1.00 to 1.01)0.063
 Age1.00 (1.00 to 1.01)0.179

  • *Pre-intervention.

  • †Costs log transformed and all effect estimates (adjusted and unadjusted) derived from generalized estimating equations, normal distribution, identity link, independent model.

  • ‡Laparoscopy.

  • §Charlson Comorbidity, no comorbidity (level 0).

  • BMI, body mass index; OR, operating room.