National Trends and Factors Associated with Hospital Costs Following Thyroid Surgery

Background: Medical costs in the United States have been increasing disproportionally to gross domestic product, raising concerns about the sustainability of U.S. healthcare expenditures. Care of patients with thyroid disease has been identified as an area of medicine where cost increases have been pronounced. Objectives: The goals of this study were to identify potential drivers of the cost of hospitalization following thyroid surgery, and to understand which of these factors may be contributing to observed increases in cost from 2003 to 2011. Methods: A retrospective cross-sectional analysis of discharge data from the Nationwide Inpatient Sample (NIS) database for all admissions following thyroid lobectomy or total thyroidectomy in the years 2003, 2007, and 2011 was performed. Multiple regression analysis via a weighted generalized linear model was used to identify factors that were independently associated with high cost of hospitalization. Trend as well as subgroup analyses were then performed to identify which of these factors could be contributing to increasing costs. Results: There were 47,854 hospital admissions following total thyroidectomy or thyroid lobectomy identified in the years 2003, 2007, and 2011. The aggregate national cost of hospitalization increased from $198 million in 2003 to $373 million in 2011 in inflation-adjusted 2011 dollars. The weighted mean cost of hospitalization following thyroid surgery increased from $6154 to $8982 from 2003 to 2011 in inflation-adjusted 2011 dollars. Higher comorbidity score, total thyroidectomy, lymphadenectomy, western region, rural region, and certain postoperative complications were the factors most highly associated with increased hospital costs. Of these, an increasing proportion of patients with higher severity of illness score and an increasing proportion of patients undergoing total thyroidectomy and lymphadenectomy were implicated as the most likely contributors to the cost increases. The rate of total thyroidectomy and lymphadenectomy was found to be increasing for patients with both benign and malignant thyroid disease. Conclusions: According to the NIS data set, costs associated with hospitalization after thyroid surgery increased markedly from 2003 to 2011. This increase could be in part due to a growing proportion of sicker patients undergoing more extensive surgery, but a number of confounders in this study limit the conclusions. Further analysis of factors that could be associated with the rising costs of inpatient thyroid surgery should be undertaken.