Predictors and Consequences of Inappropriate Thyroid Ultrasound in Hypothyroidism

Introduction In 2012, the American Board of Internal Medicine Foundation established the Choosing Wisely® initiative, partnering with specialist societies to promote evidence-based care. Under this program, the Endocrine Society recommends against ordering thyroid ultrasounds in individuals with subclinical or overt hypothyroidism and a normal neck exam. We sought to understand the prevalence, predictors, and consequences of thyroid ultrasound performed at our academic medical center that are not in compliance with this recommendation. Methods We conducted a retrospective cohort study of electronic health record data from January 1, 2016 to July 31, 2018. Data were extracted from records of all patients who underwent thyroid ultrasonography. Ultrasounds were considered inappropriate if they were ordered based on hypothyroidism, without other clear indications. Results A total of 2,021 patients underwent thyroid ultrasonography, of which 572 (28.3%) were diagnosed with hypothyroidism. Among the patients with hypothyroidism, 40 were identified as having received an inappropriate ultrasound (7.0%). Of those patients who received inappropriate ultrasounds, 42.5% had subsequent medical encounters, with a mean charge of $851 (standard deviation = $271) per patient. Using a multivariable model, the odds of receiving an inappropriate ultrasound were significantly higher for patients younger than 50 years of age (odds ratio: 2.37, 95% confidence interval: 1.01-5.58). Conclusion Seven percent of thyroid ultrasounds were inappropriately ordered in a cohort with hypothyroidism. Patients aged <50 years were at an increased risk of inappropriate ultrasound. Sequelae of inappropriate ultrasound included further medical encounters and financial burdens. Systems to reduce the inappropriate use of thyroid ultrasound may lessen the consequences of unnecessary medical imaging.