Table 2. Multivariate Analysis of Factors Associated With Operating Room Time.
| Factors | Coefficienta | P valueb |
|---|---|---|
| ln(EBL)c | 0.076 | <.001 |
| Age, y | 0.008 | <.001 |
| Age, y2 | −0.0001 | <.001 |
| Lymph nodes harvested | −0.002 | .003 |
| Vascular clamp/resection | 0.078 | <.001 |
| Concomitant procedure | 0.082 | .07 |
| Pathology | ||
| PDA | 1 [Reference] | NA |
| AMP | −0.051 | .02 |
| IPMN | −0.072 | .002 |
| NET | −0.053 | .09 |
| CCA | −0.002 | .95 |
| Other | −0.024 | .37 |
| sqrt (case No.) | −0.012 | .08 |
| Resecting surgeon group | ||
| 1st vs 2nd generation | 0.510 | <.001 |
| 3rd vs 2nd generation | 0.138 | .02 |
| sqrt (case No.) by groupc | ||
| 1st vs 2nd generation | −0.038 | <.001 |
| 3rd vs 2nd generation | 0.002 | .92 |
| Interceptd | 5.521 | <.001 |
Abbreviations: AMP, ampullary; CCA, cholangiocarcinoma; EBL, estimated blood loss; IPMN, intrapapillary mucinous neoplasm; ln, natural logarithm transformation; NA, not applicable; NET, pancreatic neuroendocrine tumor; PDA, pancreatic ductal adenocarcinoma; sqrt, square root transformation.
a
A positive coefficient indicates a predicted increase in average operation time, while a negative coefficient indicates a predicted decrease in average operation time.
b
Statistically significant values at P less than .05.
c
One missing value for EBL was substituted with the median of the nonmissing EBL values.
d
The intercept applies to all surgeries.