Impact of frailty on inpatient outcomes in thyroid cancer surgery: 10-year results from the US national inpatient sample

Background Frailty is linked to perioperative morbidity and mortality. We evaluated the impact of preoperative frailty on inpatient outcomes of patients undergoing surgery for thyroid malignancy. Methods This population-based, retrospective observational study extracted data of hospitalized patients who were 18 years and older with a primary diagnosis of thyroid cancer undergoing thyroidectomy from the US Nationwide Inpatient Sample (NIS) database (2005-2014). Participants were stratified into frail and non-frail using the Johns Hopkins (ACG) frailty-defining diagnosis indicator. Study endpoints were in-hospital mortality, incidence of surgical and medical complications and prolonged length of stay. Univariate and multivariate analysis were performed to determine associations between the endpoints and frailty. Results Data of 38,202 patients were included. After adjusting for possible confounders, frailty remained significantly associated with higher odds of in-hospital mortality (OR: 3.839, 95% CI: 1.738-8.480), prolonged length of stay (OR: 5.420, 95% CI: 3.799-7.733), surgical complications (OR: 3.144, 95% CI: 2.443-4.045) and medical complications (OR: 6.734, 95% CI: 5.099-8.893) compared with non-frailty. In patients > age 65 years, adjusted odds ratio for frailty was 4.099 (95% CI: 1.736-9.679) for in-hospital mortality, 6.164 (95% CI: 3.514-10.812) for prolonged length of stay, 3.736 (95% CI: 2.620-5.328) for surgical complications, and 5.970, 95% CI: 4.088-8.720 for medical complications, all with significance. Conclusion Frailty is associated with increased risk for adverse inpatient outcomes, including prolonged hospital stay, surgical and medical complications and mortality independent of age and comorbidities in thyroid cancer patients undergoing surgery. Study findings may provide valuable information for preoperative risk stratification.