ACS NSQIP risk calculator reliability in head and neck oncology: The effect of prior chemoradiation on NSQIP risk estimates following laryngectomy.

PURPOSE

To determine whether inclusion of chemoradiation history increases estimated risk for complications following total laryngectomy using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) Surgical Risk Calculator.

MATERIALS AND METHODS

A retrospective review of 96 patients with laryngeal cancer, approximately half of who had received prior chemoradiation, who underwent laryngectomy between January 2010 and December 2014. NSQIP estimates were calculated and compared to actual event occurrence using receiver operating characteristic (ROC) curves, Brier scores, and risk estimates.

RESULTS

Patients who had received prior chemoradiation were at significantly greater risk for complication postoperatively (OR=2.63, 95% CI=1.145-6.043). NSQIP Calculator discriminability and accuracy were generally poor for this sample. While NSQIP estimates significantly predicted risk for any postoperative complication, pneumonia, and discharge to nursing care for primary laryngectomy patients, predictive capability was lost among salvage laryngectomy patients. NSQIP adjustments to both Somewhat Higher and Significantly Higher Risk categories did not improve predictive capability. Of the risk factors considered by NSQIP, preoperative functional status (p=0.041), age at time of surgery (p<0.008), and inclusion of neck dissection (p=0.035) emerged as significant predictors of actual postoperative complications, though again estimates lost significance among salvage laryngectomy patients.

CONCLUSIONS

The NSQIP Calculator may be poorly calibrated to estimate postoperative complication risk for patients previously exposed to chemoradiation undergoing salvage laryngectomy. Caution should be used when estimating postoperative risk among patients undergoing salvage procedures, especially those of older age, poorer functional status, and those requiring neck dissection.