Table 2.

Outcomes based on nodule volume ^a.

	Total (n = 826)	Small (≤10 mL, n = 351)	Medium (11~30 mL, n = 295)	Large (>30 mL, n = 180)	Group * Time Effect p-Value c
Nodule volume (Mean ± SD, mL)					<0.001
Baseline	21.51 ± 27.13	4.77 ± 2.80	18.04 ± 5.65	59.60 ± 35.82
1 month	11.71 ± 13.75	2.78 ± 2.02	10.70 ± 5.28	30.07 ± 17.29
3 months	8.07 ± 10.23	1.89 ± 1.66	7.28 ± 4.15	21.42 ± 13.85
6 months	5.94 ± 8.83	1.15 ± 1.28	5.20 ± 4.15	10.21 ± 13.18
Time Effect p-value b	<0.001	<0.001	<0.001	<0.001
Volume reduction ratio (Mean ± SD, %)					<0.001
1 month	37.76 ± 48.80	30.25 ± 70.10 d,e	40.85 ± 20.88 d,f	47.13 ± 21.51 e,f
3 months	59.29 ± 25.65	57.95 ± 32.08 g,h	59.39 ± 19.39 g,i	61.76 ± 19.62 h,i
6 months	73.24 ± 23.19	74.62 ± 28.64 j,k	72.12 ± 18.23 j,l	72.51 ± 18.52 k,l
Time Effect p-value	<0.001	<0.001	<0.001	<0.001
Cosmetic Score (0–3)
Baseline	2.53 ± 1.09	2.01 ± 1.17	2.91 ± 0.89	3.00 ± 0.69	<0.001
6 months	0.91 ± 0.97	0.38 ± 0.62	1.11 ± 0.93	1.70 ± 0.98	<0.001
Time Effect p-value	<0.001	<0.001	<0.001	<0.001
Symptoms Score (0–5)
Baseline	1.75 ± 1.41	1.40 ± 1.33	2.02 ± 1.47	2.04 ± 1.33	<0.001
6 months	0.13 ± 0.42	0.03 ± 0.18	0.13 ± 0.39	0.34 ± 0.69	<0.001
Time Effect p-value	<0.001	<0.001	<0.001	<0.001
Complications
Voice change	22	10	4	8
Delay nodular rupture	9	1	1	7
Ptosis	2	1	0	1
Hyperthyroidism	2	1	0	1
Hematoma	4	0	1	3
Skin burn	1	0	0	1
Total	40 (4.8%)	13 (3.7%)	6 (2.0%)	21 (11.6%)	<0.001

^a Generalized estimation equation analysis was used for repeated measurement analysis of volume change and volume reduction ratio at different time outcomes. ^b Time effect defined as volume differences of the same group between different times. The baseline measurements were the reference categories. ^c Group * (multiplied by) time effect is defined as change of volume for different volume groups at 6 months. ^d p= 0.035; ^e p < 0.001; ^f p = 0.01; ^g p = 1.00; ^h p = 0.295; ⁱ p = 0.634; ^j p = 0.570; ^k p = 0.953; ^l p = 1.00.