Preoperative Risk Index Among Patients Undergoing Thyroid or Parathyroid Surgery

Frailty represents a multidimensional syndrome that is increasingly being used to stratify risk in surgical patients. Current frailty risk models are limited among those undergoing thyroid or parathyroid surgery.

To develop and compare preoperative risk indices to determine factors associated with short-term major postoperative adverse events in patients undergoing thyroid or parathyroid surgery.

This cohort study evaluated 154 895 patients in the American College of Surgeons National Surgical Quality Improvement Program who underwent thyroid or parathyroid surgery from January 1, 2007, to December 31, 2016.

Preoperative frailty-related and surgical factors from a derivation cohort were evaluated using simple and multiple logistic regression. Variables potentially associated with postoperative adverse events were subsequently combined into a personalized preoperative Cervical Endocrine Surgery Risk Index (CESRI) and compared with existing risk models using the validation cohort.

Composite variable of any major postoperative adverse event, including death, within 30 days of surgery.

Of the 154 895 operations reviewed, 3318 patients (2.1%; 2296 women and 1022 men; mean [SD] age, 56.1 [15.6] years) experienced a major postoperative adverse event, with 163 deaths (0.1%). Older age (age, ≥80 years: odds ratio [OR], 2.35; 95% CI, 1.74-3.13), inpatient status (OR, 3.55; 95% CI, 3.08-4.11), male sex (OR, 1.49; 95% CI, 1.29-1.71), current tobacco smoking (OR, 1.25; 95% CI, 1.05-1.48), dyspnea (OR, 1.58; 95% CI, 1.29-1.91), recent weight loss (OR, 1.88; 95% CI, 1.23-2.78), functional dependence (OR, 2.77; 95% CI, 2.05-3.69), obesity (OR, 1.33; 95% CI, 1.10-1.60), anemia (OR, 2.14; 95% CI, 1.82-2.52), leukocytosis (OR, 1.73; 95% CI, 1.38-2.14), hypoalbuminemia (OR, 1.87; 95% CI, 1.56-2.23), use of anticoagulation (OR, 2.16; 95% CI, 1.64-2.81), and length of surgery (>4 hours: OR, 2.92; 95% CI, 2.37-3.59) were independently associated with major adverse events or death on multiple regression analysis (C statistic, 0.77; 95% CI, 0.76-0.78). The area under the curve of the CESRI to determine major adverse events, including death, using the validation cohort was 0.63 (95% CI, 0.61-0.64), with a sensitivity of 0.66 (95% CI, 0.64-0.68) and specificity of 0.66 (95% CI, 0.65-0.66). The CESRI outperformed other risk models for determining adverse events (CESRI vs 5-Factor Modified Frailty Index: delta C index, 0.11; 95% CI, 0.09-0.13; CESRI vs American Society of Anesthesiologists Physical Status Classification System: delta C index, 0.05; 95% CI, 0.03-0.07; CESRI vs American College of Surgeons Risk Calculator: delta C index, 0.02; 95% CI, 0.01-0.03; and CESRI vs Head and Neck Surgery Risk Index: delta C index, 0.04; 95% CI, 0.03-0.06).

This study suggests that the CESRI is able to determine major postoperative adverse events in patients undergoing thyroid or parathyroid surgery.