The Effect of Iodine Status on the Risk of Thyroid Nodules: A Cross-Sectional Study in Zhejiang, China

Figure 1

The nonlinear and linear associations between urinary iodine concentration and prevalence of thyroid nodule: (a) the linear relationship between urinary iodine concentration and prevalence of thyroid nodule was observed with adjusted R² = 73.6%; (b) the quadratic curve existed between urinary iodine concentration and prevalence of thyroid nodule with adjusted R² = 98.6%; (c) the nonlinear relationship between urinary iodine concentration and prevalence of thyroid nodule was observed by using spline function with adjusted R² = 98.5%.

(a)

(b)

(c)