Reclassification of Thyroid Disease Diagnoses Using Age, Sex, and Race-Specific Standards

Recent research highlights the significance of utilizing age, sex, and race-specific reference intervals for thyroid function tests to improve the accuracy of diagnosing thyroid diseases. A comprehensive cross-sectional study analyzed data from both the U.S. NHANES and a Chinese health database, revealing that adjusting diagnostic thresholds based on demographic factors could lead to substantial reclassification of patients.

The findings demonstrate that traditional uniform reference intervals may overlook or misclassify many cases, especially subclinical hypothyroidism and hyperthyroidism. By applying tailored intervals, nearly half of those previously diagnosed with subclinical hypothyroidism were reclassified as having normal thyroid function, with similar trends observed for hyperthyroidism diagnoses.

Key variations identified include an increase in thyroid-stimulating hormone (TSH) levels with age, a decline in total triiodothyronine (TT3), and no significant change in total thyroxine (TT4). Women generally exhibited higher TT4 levels, while white individuals had elevated TSH levels. The study emphasizes that race, sex, and age significantly influence thyroid test results, and personalized reference ranges could reduce unnecessary treatment and improve disease management.

These insights aim to guide healthcare providers in refining diagnostic criteria and support the development of standardized, demographically sensitive protocols for thyroid disease assessment. The study was published in the Annals of Internal Medicine and provides a critical step toward more precise and individualized healthcare.

Source: https://medicalxpress.com/news/2025-05-age-sex-specific-standards-reclassify.html