Table 2.

Relationship between serum fibrinogen levels and clinical characteristics in the training and testing sets of PTC patients

	Training set			Testing set
	Serum fibrinogen level			Serum fibrinogen level
Factor	Low	High	p	Low	High	p
All patients	402	12		575	34
Age (years)			0.017			0.693
≤45	239	3		328	18
>45	163	9		247	16
Age (years)			0.046			0.378
≤55	349	8		474	26
>55	53	4		101	8
Gender			0.441			0.394
Female	295	10		400	26
Male	107	2		175	8
Postoperative RAI			0.683			0.884
Yes	221	7		324	20
No	181	5		251	14
Race			0.215			0.906
Han	392	11		560	33
Other	10	1		15	1
BRAF mutation			0.642			0.073
Positive	49	2		125	3
Negative	74	3		84	4
Unknown	279	7		366	27
T classification			0.001			0.001
T1	160	0		189	8
T2	8	3		12	1
T3	181	5		279	15
T4	53	4		95	10
PTC nodule number			0.001			<0.001
Single	345	6		509	22
Multiple	57	6		66	12
Capsule invasion			0.068			0.036
Presence	194	10		266	22
Absence	208	2		309	12
Strap muscles invasion			<0.001			0.013
Presence	40	6		68	9
Absence	362	6		507	25
RLN invasion			<0.001			0.001
Presence	9	2		44	8
Absence	393	10		531	26
Esophagus invasion			<0.001			0.009
Presence	6	2		18	4
Absence	396	10		557	30
Trachea invasion			<0.001			<0.001
Presence	3	3		11	5
Absence	399	9		564	29
N classification			0.186			0.604
N0	193	3		279	14
N1a	149	7		183	14
N1b	60	2		113	6
M classification			<0.001			<0.001
M0	400	10		569	30
M1	2	2		6	4
PTC recurrence			0.002			0.002
No	373	8		547	28
Yes	29	4		28	6
AJCC stage			0.004			0.047
I	268	4		392	20
II	62	2		100	3
III	70	4		77	7
IV	2	2		6	4