Table 5.

Multivariate logistic model with intraoperative factors in addition to preoperative predictor variables at higher risk for SSI.

Variable	Odds ratio	95% Confidence interval	P value
Clean-contaminated wound	6.1	3.6, 10.3	<0.001
Operative time (for each extra min)	1.004	1.002, 1.006	<0.001
Obesity (BMI > 30)	1.8	1.3, 2.5	0.001

Variables also included in model that were not associated with significant OR predicting SSI were partial thyroidectomy, thyroidectomy with central lymph node dissection, thyroidectomy with radical lymph node dissection, reoperative thyroidectomy, thyroidectomy with substernal goiter, underweight (BMI <19), diabetes (insulin-controlled, diet-controlled, or oral agents), alcohol use, steroid use, history of CHF, history of COPD, weight loss > 10%, and partially or totally dependent functional status.