Reference intervals for thyroid-stimulating hormone, free thyroxine, free triiodothyronine, and total triiodothyronine in the Lebanese adult population.

Background: For a better assessment of thyroid function, each laboratory should establish its own reference intervals (RI). In Lebanon, no previous study has been conducted to establish the reference values for thyroid function tests.

Methods: This cross-sectional study included 301 volunteers aged between 18 and 65 years (65.