Table 2.

Comparison of clinical characteristics according to the presence of goiter on the US based on age-specific criteria. Data are expressed as the mean ± s.d., median (interquartile range), or n (%).

Variables	Goiter-US (−)	Goiter-US (+)	P
n	169	59
Boys, n (%)	94 (55.6)	29 (49.2)	0.999
BMI Z-score	−0.21 ± 0.94	0.11 ± 0.97	0.030
Body surface area, m2	0.82 ± 0.07	0.83 ± 0.06	0.051
Palpable goiter at physical examination	23 (13.6)	20 (33.9)	0.001
Parental history of thyroid disease	7 (4.1)	3 (5.1)	0.999
Maternal education level ≥ college	146 (86.4)	50 (84.8)	0.924
Free thyroxine, ng/dL	1.17 ± 0.10	1.15 ± 0.12	0.177
Thyroid-stimulating hormone, mIU/L	2.5 (1.8–3.4)	2.5 (1.9–3.1)	0.974
Subclinical hypothyroidism	13 (7.7)	2 (3.4)	0.399
Thyroid volume, mL	2.2 ± 0.4	3.5 ± 0.5	<0.001
Goiter-US based on BSA-specific criteria	22 (13.0)	57 (96.6)	<0.001
Focal lesiona	44 (26.0)	31 (52.5)	<0.001

^aFocal lesion was defined as thyroid cysts, nodules, or intrathyroidal thymus.

BSA, body surface area; US, ultrasound.