Prevalence and Trends of Thyroid Disease Among Adults, 1999-2018

Thyroid disease is a prominent endocrine disorder, yet the clinical epidemiology of this condition remains unclear. This study aims to describe the recent trends in the prevalence of thyroid disease in US adults from 1999-2018.

This cross-sectional study used nationally representative data collected through the National Health and Nutrition Examination Survey (NHANES) from January 1, 1999 to December 31, 2018. Patients with thyroid disease were defined as patients who reported having a thyroid disease and were on thyroid-related treatment. Age-standardized prevalence of thyroid disease was calculated within 4-year survey periods (1999-2002, 2003-2006, 2007-2010, 2011-2014, and 2015-2018).

During the NHANES 1999-2018, a total of 57 540 participants were examined. The age-standardized prevalence of thyroid disease was 5.05% (95% CI, 4.55%-5.60%) from 2015-2018, signifying a significant increase from the 1999-2002 period (P <.0002). However, prevalent thyroid disease remained steady between 2003 and 2014. The highest prevalence of thyroid disease was observed in non-Hispanic Whites (8.1%; 95% CI, 7.3%-9.0%), individuals aged ≥60 years (15.4%; 95% CI, 13.3%-17.8%), and tended to be higher in women (7.6%; 95% CI, 6.8%-8.5%). Multiple regression analysis revealed that age, women sex, non-Hispanic White and Mexican American, body mass index, higher education and incomes were independently associated with increased risks of thyroid disease.

The age-standardized prevalence of thyroid disease among US adults increased from 1999-2003, remained stable between 2003 and 2014, and then saw an increase from 2014-2018, with the highest rate observed among elders, women, and non-Hispanic Whites.