SUN-388 Distribution of Outpatient Visits Among Adults with Hypothyroidism: NAMCS 2010-2019

Abstract Disclosure: M. Ramirez: None. M. Ettleson: None. Introduction: Hypothyroidism is a widespread chronic condition in the US, affecting approximately 30 million adults. As the demand for hypothyroidism care increases, novel care approaches will be needed to achieve improvements in disease control. Gaining a comprehensive understanding of where patients with hypothyroidism seek care is critical. This study aims to estimate national trends in outpatient care visits for US adults with hypothyroidism. Methods: We analyzed data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2010 - 2019. Our analysis included those visits for adults aged 18 years or older. All visits were categorized by setting: 1) primary care, 2) medical specialty care, 3) surgical specialty care, and 4) emergency care. All visits that were associated with a diagnosis of hypothyroidism or a prescription for thyroid hormone were included. We examined two primary outcomes: (1) the annual mean count of visits for patients with hypothyroidism, and (2) the subset of those visits for which thyroid disease was listed as a reason for the visit. Results: An estimated 30 million primary care annual visits took place annually for patients with hypothyroidism, and another 15.4 million annual visits to medical specialists. Of those primary care visits, thyroid disease was a reason for visit for approximately 3.3 million visits (10.8% [9.7 - 11.9%]). Approximately 65% (58.3 - 71.6%) of all outpatient visits for patients with hypothyroidism for which thyroid disease was a reason for visit occurred in the primary care setting, compared to 29.6% (21.7 - 37.4%) in the medical specialty setting, and 4.4% (3.4 - 5.5%) in the surgical specialty setting. Primary care visits had a higher proportion of younger patients, females, and individuals from minority racial or ethnic backgrounds compared to specialist office visits. Emergency visits were highlighted by a higher proportion of black patients and those on Medicaid. Patients in primary care visits had a higher prevalence of hypertension and obesity compared to those in other care settings. In contrast, emergency department visits recorded the highest rates of ischemic heart disease, heart failure, and stroke. Surgical specialty clinics, however, were characterized by a lower overall burden of comorbidities. Conclusion: The majority of outpatient visits for U.S. adults with hypothyroidism took place in primary care settings. Emergency visits were highlighted by a higher proportion of black patients and those on Medicaid. These findings highlight the need to focus on primary care as a key intervention point to improve disease control in hypothyroidism. It is also apparent that emergency departments continue to serve a critical role in hypothyroidism care and may be an area of focus for disparities in thyroid care. Presentation: Sunday, July 13, 2025