A. D. McDow1, W. E. Zahnd1, P. Angelos2, N. Lanzotti1, J. D. Mellinger1, S. Ganai1 1Southern Illinois University School Of Medicine,General Surgery,Springfield, IL, USA 2University Of Chicago,Endocrine Surgery,Chicago, IL, USA
Introduction:
Thyroid cancer is the most rapidly increasing malignancy in the United States. Prior analysis of rural-urban differences in population-level thyroid cancer incidence and survival revealed that lower incidence rates were seen in rural counties, which were also associated with significantly lower survival. In this study, we sought to evaluate the impact of provider density on outcome. We hypothesized that survival would be improved for patients living in counties with greater density of endocrinologists and/or thyroid surgeons.
Methods:
An observational study was performed on 90,286 patients who underwent surgical management of follicular and papillary thyroid cancer using the Surveillance Epidemiology and End Results (SEER) database from 2000-2012. United States Department of Agriculture Rural Urban Continuum Codes were used to categorize counties as urban or rural. Density of general surgeons and otolaryngologists (i.e., the number of potential thyroid surgeons), as well as the density of endocrinologists per 100,000 residents were calculated per county. Multivariable Cox regression analysis was used to assess the relationship between provider density and cause-specific survival controlling for demographic, socioeconomic, and treatment characteristics.
Results:
Patients were 78.5% female, 91.3% resided in urban counties, and 55.5% were over 45 years old. 70.6% presented with localized disease and 85.9% underwent total thyroidectomy. Median endocrinologist density was 1.4 per 100,000 and surgeon density was 14.8 per 100,000. 15.5% of patients lived in a county without an endocrinologist and only 1.7% lived in a county without a surgeon. Decreased survival was noted for those living in counties below the median density of surgeons (Log rank p=0.02) and endocrinologists (p=0.004). Cox regression analysis demonstrated endocrinologist density was significantly associated with improved survival (HR 0.89; 95% CI, 0.82-0.97; p=0.007), suggesting that an increase in one endocrinologist per 100,000 people improves survival odds by 11%. Living in a rural county (HR 1.29; 95% CI, 1.07-1.56; p=0.009), age greater than 45 years (HR 13.00; 95% CI, 10.20-16.58; P<0.001), male gender (p<0.001), and advanced stage (p<0.001) were also independently associated with lower survival. There was no significant association between surgeon density and survival (HR 0.99; 95% CI, 0.98-1.00; p=0.06).
Conclusion:
This study demonstrates that endocrinologist density is significantly associated with improved survival in patients with follicular and papillary thyroid cancer. There was no association between surgeon density and survival, although this variable may not reflect the impact of surgeons with a focused interest in thyroid or endocrine surgery. The findings may reflect the importance of an endocrinologists’ role in diagnosis and treatment of thyroid cancer, or as a surrogate marker for counties with better overall access to care.