Predictive effect of modified frailty index on postoperative nausea and vomiting in thyroid cancer patients

Postoperative nausea and vomiting (PONV) are common complications following thyroid cancer surgery, impacting patient well-being, prognosis, and potentially leading to severe complications. Frailty, a critical risk factor for postoperative complications, has not been thoroughly investigated concerning PONV in thyroid cancer patients. This study aimed to explore the correlation between frailty and PONV in thyroid cancer patients. A retrospective analysis was conducted on 908 patients who underwent radical thyroid cancer surgery at Jinan Central Hospital between January 2016 and September 2022. Patients were classified into the PONV group (626 patients) and the non-PONV group (282 patients). General and clinical data were collected for comparison. Independent risk factors for PONV were identified using univariate and multivariate logistic regression analyses. ROC curves evaluated the diagnostic efficiency of various indicators. A predictive model for PONV risk factors was developed, verified using ROC curves, and a scoring system was established. Age, Apfel score, modified frailty index (mFI) score, free fatty acids, uric acid, homocysteine (HCY), and fasting blood glucose were identified as independent risk factors for PONV through multivariable logistic regression analysis. The model achieved an area under the curve of 0.893 (0.871-0.915) in the ROC curve, with a sensitivity of 83.2%, specificity of 79.1%, and a maximum Youden index value of 0.623. mFI exhibited the strongest correlation with PONV post-radical thyroid cancer surgery, with a correlation coefficient of 0.523. The modified frailty index is a significant predictor of postoperative nausea and vomiting in patients undergoing thyroid cancer surgery.