A NSQIP risk assessment for thyroid surgery based on comorbidities

Abstract

Background: Thyroid surgery is associated with low mortality and morbidity and often is performed in an ambulatory setting. The majority of patients undergoing thyroidectomy have an uncomplicated outcome, but common comorbidities may increase mortality and morbidity. Due to low complication rates, studies using single surgeon or single institutional data to identify risk factors for adverse outcomes may be limited by inadequate patient volume.

Study design: This retrospective cohort study used data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). The study group included all thyroidectomy patients over a 6-year period (2005 to 2010). Common patient comorbidities were identified and analyzed using logistic regression. Risk of adverse outcomes was calculated for single and multiple comorbidities. Statistical significance was set at p < 0.05.

Results: The study group included 38,577 consecutive patients. Thirty-day mortality and postoperative morbidity were 0.06% and 1.49%, respectively. The risk factors independently associated with morbidity included hypertension, diabetes, advanced age greater than 70 years, COPD, dialysis, malignant thyroid disease, and surgical approach (total thyroidectomy). Substernal thyroidectomy, hypertension, diabetes, age greater than 70 years, COPD, and dialysis were significant predictors (unadjusted) of mortality. Multiple comorbidities resulted in significant cumulative risk. The presence of 3 or more comorbidities was associated with a postoperative morbidity of 5.1% (p < 0.001) and mortality as high as 12.5%.

Conclusions: Thyroid surgery is generally safe. Common comorbidities significantly increase the risk of adverse outcomes and death. Clinically applicable risk calculation based on overall health may improve patient selection, surgical management, and informed consent.