Accuracy of an administrative database for pancreatic cancer by international classification of disease 10th codes: A retrospective large-cohort study

Table 1 Diagnostic criteria of pancreatic cancer

Diagnostic criteria	Methods	Positive finding
Definite criteria
Pathologic analysis	Endoscopy, ERCP, EUS-FNA, Surgery	Adenocarcinoma Mucinous carcinoma Adenosquamous carcinoma Other malignant neoplasm
Possible criteria
Imaging finding	CT, MRI, ERCP, MRCP, EUS, endoscopy, PET	Focal hypo-attenuated lesion Pancreatic duct dilation Distal pancreatic parenchymal atrophy Involvement of the surrounding vascular structures or other organs
Clinical features	Medical record	Clinical courses compatible with PC
Tumor marker	CA19-9	> 100 U/mL
	αFP	To exclude other malignancies including hepatocellular carcinoma

CT: Positron emission tomography; MRI: Magnetic resonance imaging; ERCP: Endoscopic retrograde cholangiopancreatography; MRCP: Magnetic resonance cholangiopancreatography; EUS: Endoscopic ultrasound; PET: Positron emission tomography; FNA: Fine needle aspiration; CA19-9: Carbohydrate antigen 19-9; αFP: α-fetoprotein; PC: Pancreatic cancer.

Table 2 Cancer cell type of pancreatic cancer

	Adenocarcinoma	Adeno-squamouscarcinoma	Neuroendocrinetumor	Total
C250	163	0	1	164
C251	33	0	0	33
C252	45	0	0	45
C253	2	0	0	2
C254	2	0	0	2
C257	1	0	0	1
C259	640	3	14	657
	886 (98.0)1	3 (0.3)	15 (1.7)	904

¹Number of patients (%).

Table 3 Characteristics of patients with pancreatic cancer according to the international classification of diseases, 10^th revision edition

Parameters	N (%)	C250	C251	C252	C253	C254	C257	C259
Number of patients	1846	234 (12.7)2	72 (3.9)	104 (5.6)	5 (0.3)	2 (0.1)	1 (0.1)	1428 (77.4)
Age at diagnosis	65.22 ± 11.971	64.72 ± 10.14	63.39 ± 10.48	65.43 ± 11.32	65.20 ± 11.08	70.50 ± 4.95	45.00 ± 0.00	65.39 ± 12.35
Gender (male: Female)	1116:730	150:84	45:27	52:52	1:4	2:0	1:0	865:563
Diagnostic criteria
Definite	910 (49.3)	164 (70.1)	34 (47.2)	45 (43.3)	2 (40.0)	2 (100.0)	1 (100.0)	662 (46.4)
Possible	936 (50.7)	70 (29.9)	38 (52.8)	59 (56.7)	3 (60.0)	0 (0.0)	0 (0.0)	766 (53.6)
Methods of pathologic diagnosis (n = 910)
ERCP or endoscopy	163 (17.9)	34 (20.7)	2 (5.9)	8 (17.8)	0 (0.0)	0 (0.0)	0 (0.0)	119 (18.0)
EUS-FNA or percutaneous biopsy	30 (3.3)	4 (2.4)	0 (0.0)	2 (4.4)	0 (0.0)	0 (0.0)	0 (0.0)	26 (3.9)
Surgery	717 (78.8)	126 (76.8)	32 (94.1)	35 (77.8)	2 (100.0)	2 (100.0)	1 (100.0)	517 (78.1)
CA19-9 > 100 U/L
Yes	684 (37.1)	95 (40.6)	29 (40.3)	44 (42.3)	1 (20.0)	0 (0.0)	0 (0.0)	515 (36.1)
No	514 (27.8)	63 (26.9)	24 (33.3)	23 (22.1)	1 (20.0)	1 (50.0)	0 (0.0)	402 (28.2)
Missing	648 (35.1)	76 (32.5)	19 (26.4)	37 (35.6)	3 (60.0)	1 (50.0)	1 (100.0)	511 (35.8)

¹Median ± standard deviation.

²Number (%).

Table 4 Diagnostic accuracy of pancreatic cancer diagnosed by the international classification of diseases, 10^th revision edition in the administrative database

		Status of PC		Total
		Positive	Negative
Definite diagnostic criteria
ICD codes of PC	Outcome positive	True positive	False positive	910
		904	6
	Outcome negative	False negative	True negative	1846
		1	1845
	Total	905	1851	2756
Possible diagnostic criteria
ICD codes of PC	Outcome positive	True positive	False positive	936
		918	18
	Outcome negative	False negative	True negative	1846
		1	1845
	Total	919	1863	2782
Overall diagnostic criteria
ICD codes of PC	Outcome positive	True positive	False positive	1846
		1822	24
	Outcome negative	False negative	True negative	1846
		1	1845
	Total	1823	1869	3692

ICD: International classification of disease. PC: Pancreatic cancer.

Table 5 Diagnostic accuracy of pancreatic cancer according to tumor sites by the international classification of diseases, 10^th revision edition

ICD codes	Overall diagnosis		Definite diagnosis				Possible diagnosis
	True (+)1	False (+)2	Total	True (+)	False (+)	Total	True (+)	False (+)	Total
Cell types	234	0	234	164	0	164	70	0	70
C251	71	1	72	30	1	31	41	0	41
C252	104	0	104	48	0	48	56	0	56
C253	5	0	5	2	0	2	3	0	3
C254	2	0	2	2	0	2	0	0	0
C257	1	0	1	1	0	1	0	0	0
C259	1405	23	1428	657	5	662	748	18	766
	1822	24	1846	904	6	910	918	18	936

¹Real cancer patients with ICD 10th codes of cancer.

²No cancer patients with ICD 10th codes of cancer. ICD: International classification of disease.

Table 6 Diagnostic power of international classification of diseases, 10^th revision edition for pancreatic cancer

	Overall diagnosis		Definite diagnosis		Possible diagnosis
	Point estimate (%)	95%CI (%)	Point estimate (%)	95%CI (%)	Point estimate (%)	95%CI (%)
Sensitivity	99.95	99.94-99.95	99.89	99.88-99.90	99.89	99.88-99.90
Specificity	98.72	98.70-98.73	99.68	99.67-99.68	99.03	99.02-99.05
Positive predictive value	98.70	98.68-98.72	99.34	99.32-99.36	98.08	98.05-98.11
Negative predictive value	99.95	99.94-99.95	99.95	99.94-99.95	99.95	99.94-99.95

CI: Confidence interval.