Positive predictive values of ICD-10 codes to identify incident acute pancreatitis and incident primary malignancy in the Scandinavian national patient registries among women with postmenopausal osteoporosis

Figures & data

Table 1 Characteristics of potential cases of acute pancreatitis stratified by hospital medical record status

Characteristic	Hospital medical record status
	Sampled N=164	Obtained N=145
Age, mean (SD)	77 (11.0)	77 (11.0)
Country of residence, n (%)
Denmark	60 (36.6)	42 (29.0)
Norway	54 (32.9)	54 (37.2)
Sweden	50 (30.5)	49 (33.8)
Case year, n (%)
2006	≤3 (≤2%)	≤3 (≤2%)
2007	≤3 (≤2%)	≤3 (≤2%)
2008	15 (9.1)	15 (10.3)
2009	12 (7.3)	10 (6.9)
2010	34 (20.7)	26 (17.9)
2011	36 (22.0)	32 (22.1)
2012	42 (25.6)	39 (26.9)
2013	13 (7.9)	13 (9.0)
2014	6 (3.7)	6 (4.1)
Hospital department, n (%)
Cardiology	4 (2.4)	≤3 (≤2%)
Emergency room	≤3 (≤2%)	≤3 (≤2%)
Endocrinology	≤3 (≤2%)	≤3 (≤2%)
Gastroenterology	13 (7.9)	12 (8.3)
Geriatrics	≤3 (≤2%)	≤3 (≤2%)
Internal medicine	19 (11.6)	17 (11.7)
Surgery	119 (72.6)	105 (72.4)
Other	≤3 (≤2%)	≤3 (≤2%)
Diseases, chronic, n (%)
Cystic fibrosis	0 (0.0)	0 (0.0)
Diabetes	10 (6.1)	9 (6.2)
Type I diabetes	5 (3.0)	4 (2.8)
Type II diabetes	5 (3.0)	5 (3.4)
Overweight or obesity	≤3 (≤2%)	≤3 (≤2%)
Diseases, other, n (%)
Gallstones	6 (3.7)	6 (4.1)
Biliary disease	7 (4.3)	6 (4.1)
Hyperlipidemia	5 (3.0)	5 (3.4)
Hypertriglyceridemia	0 (0.0)	0 (0.0)
Medications, n (%)
Antidiabetics	12 (7.3)	10 (6.9)
Other, n (%)
Alcohol abuse	≤3 (≤2%)	≤3 (≤2%)
Post-endoscopic retrograde cholangiopancreatography	8 (4.9)	7 (4.8)

Notes: Age was age at time of admission for acute pancreatitis identified by the case algorithm utilizing the national patient registries. Case year refers to year of admission.

Table 2 Characteristics of potential cases of primary malignancy stratified by hospital medical record status

Characteristic	Hospital medical record status
	Sampled N=161	Obtained N=141
Age, mean (SD)	77 (9.1)	77 (9.0)
Country of residence, n (%)
Denmark	70 (43.5)	50 (35.5)
Norway	48 (29.8)	48 (34.0)
Sweden	43 (26.7)	43 (30.5)
Case year, n (%)
2008	9 (5.6)	9 (6.4)
2009	8 (5.0)	8 (5.7)
2010	25 (15.5)	21 (14.9)
2011	43 (26.7)	39 (27.7)
2012	54 (33.5)	42 (29.8)
2013	9 (5.6)	9 (6.4)
2014	13 (8.1)	13 (9.2)
Hospital department, n (%)
Cardiology	≤3 (≤2%)	≤3 (≤2%)
Endocrinology	≤3 (≤2%)	≤3 (≤2%)
Gastroenterology	4 (2.5)	4 (2.8)
Geriatrics	12 (7.5)	12 (8.5)
Gynecology	11 (6.8)	7 (5.0)
Internal medicine	19 (11.8)	19 (13.5)
Oncology	27 (16.8)	27 (19.1)
Pulmonology	15 (9.3)	15 (10.6)
Surgery	53 (32.9)	38 (27.0)
Other	17 (10.6)	16 (11.3)
Diseases, chronic, n (%)
Colorectal polyps	0 (0.0)	0 (0.0)
Ulcerative colitis	≤3 (≤2%)	≤3 (≤2%)
Crohn’s disease	≤3 (≤2%)	≤3 (≤2%)
Familial adenomatous polyposis	0 (0.0)	0 (0.0)
Obesity	≤3 (≤2%)	≤3 (≤2%)
Polycystic ovarian syndrome	0 (0.0)	0 (0.0)
Medications, n (%)
Hormone replacement therapy	16 (9.9)	14 (9.9)
Tamoxifen	0 (0.0)	0 (0.0)
Other, n (%)
Tobacco use disorder	0 (0.0)	0 (0.0)
Family history of cancers	0 (0.0)	0 (0.0)

Notes: Age was age at time of admission/hospital contact for incident primary malignancy identified by the case algorithm utilizing the national patient registry. Case year refers to year of admission/hospital contact as recorded in the respective national patient registries.

Table 3 PPVs for acute pancreatitis and primary malignancy

Sample	Obtained medical records, n	Cases with insufficient information, n (%)	Confirmed casesa after medical record review, n	PPVsb of cases with sufficient information, % (95% CI)
Overall
Acute pancreatitis	145	16 (11.0)	113	87.6 (80.8–92.2)
Primary malignancy (excluding non-melanoma skin cancer)	141	15 (10.6)	111	88.1 (81.3–92.7)
Denmark
Acute pancreatitis	42	2 (4.8)	33	82.5 (68.1–91.3)
Primary malignancy (excluding non-melanoma skin cancer)	50	4 (8.0)	41	89.1 (77.0–95.3)
Norway
Acute pancreatitis	54	14 (25.9)	37	92.5 (80.1–97.4)
Incident primary malignancy (excluding non-melanoma skin cancer)	48	8 (16.7)	38	95.0 (83.5–98.6)
Sweden
Acute pancreatitis	49	0 (0.0)	43	87.8 (75.8–94.3)
Primary malignancy (excluding non-melanoma skin cancer)	43	3 (7.0)	32	80.0 (65.2–89.5)

Notes:

a Confirmed cases based on medical record review.

b PPV is calculated as the number of confirmed cases after medical record review divided by the number of obtained medical charts with sufficient information.

Abbreviation: PPVs, positive predictive values.

Figure S1 Data entry form for acute pancreatitis.

Figure S2 Data entry form for incident primary malignancy.

Table S1 Codes used for identification algorithm of postmenopausal osteoporotic women

Description	Code type	Codes
Osteoporosis	ICD-10 code	M80, M81, M82
Algorithm for identification of fractures
Fracture of hip, radius/ulna, spine, pelvis, femur or humerus. The supplementary character positions which indicate open fractures are not used in Denmark.	ICD-10 code (Denmark)	S72.xa, S52.x, S12.0, S12.1, S12.2, S12.7, S12.9, S22.0, S22.1, S32.x, S42.2, S42.3, S42.4, S42.7, S42.8, T08
Fracture of hip, radius/ulna, spine, pelvis, femur or humerus, excluding open fractures whenever possible	ICD-10 code (Sweden)	S72.x, S52.x, S12.0, S12.1, S12.2, S12.7, S12.9, S22.0, S22.1, S32.x, S42.2, S42.3, S42.4, S42.7, S42.8, T08
		Excluding S72.x1, S52.01, S52.11, S52.21, S52.31, S52.41, S52.71, S52.81, S52.91, S12.01, S12.11, S12.21, S12.71, S12.91, S22.01, S22.11, S32.x1, S42.21, S42.31, S42.41, S42.71, S42.81
Algorithm for identification of external cause of injury
Transport accidents	ICD-10 codes (Sweden)	V01-V99
Falls, all other than falls on the same levels	ICD-10 codes (Sweden)	W02, W04-W17, W19
Accidents due to exposure to inanimate mechanical forces	ICD-10 codes (Sweden)	W20-W49
Accidents due to exposure to animate mechanical forces	ICD-10 codes (Sweden)	W50-W64
Case algorithm for osteoporosis medications
ATC Description
Bisphosphonate prescription	ATC Code	M05BA, M05BB
Raloxifene	ATC Code	G03XC01
Ipriflavone	ATC Code	M05BX01
Strontium ranelate	ATC Code	M05BX03
Denosumab	ATC Code	M05BX04
Teriparatide or parathyroid hormone	ATC Code	H05AA
Calcitonin	ATC Code	H05BA
Description	ATC Code	Treatment code (Denmark only)
Treatment with bisphosphonates in hospital	ATC Code	BWHB40, BWHB40A

Note:

a x indicates any digit from 0–9 available in the coding system.

Abbreviations: ICD-10, International Classification of Diseases, 10th Revision; ATC, anatomic therapeutic chemical.

Table S2 Algorithm for exclusion criteria among postmenopausal osteoporotic women

Diagnosis	Code type	Codes
Cancer diagnosis (excluding non-melanoma skin cancer)b	ICD-10 in the national registries of patients	C00xxa – C43xx, C45xx – C97xx
Paget’s disease	ICD-10 in the national registries of patients	M88.xx

Notes:

a x indicates any digit from 0–9 available in the coding system.

b Both inpatient and outpatient.

Abbreviation: ICD-10, International Classification of Diseases, 10th Revision.

Table S3 Case identification algorithms

Diagnosis	Code type	Codes
Acute pancreatitisb	ICD-10 in the national patient registries	K85
Cancer diagnosis (excluding non-melanoma skin cancer)c	ICD-10 in the national patient registries	C00xxa – C43xx, C45xx – C97xx

Notes:

a x indicates any digit from 0–9 available in the coding system.

b Inpatient care and primary diagnosis only.

c Both inpatient and outpatient, including both principal and secondary diagnosis.

Abbreviation: ICD-10, International Classification of Diseases, 10th Revision.