Table 4.

Agreement between ICD-9 and ICD-10 diagnosis codes for type 1 and type 2 diabetes

	N=36,861			N=36,861
	> 50% type 1 ICD-9 codes N=1,269	>= 50% type 2 ICD- 9 codes N=30,373	No type 1 or type 2 ICD-9 codes N=5,219	Type 1 diabetes per Klompas algorithm N=1514	Not type 1 diabetes per Klompas algorithm N=35,347
At least one type 1 ICD-10 code	1,190 (93.8%)	321 (1.1%)	60 (1.1%)	1,292 (85.3%)	279 (0.8%)
At least one type 2 ICD-10 code	247 (19.5%)	26,011 (85.6%)	2,620 (50.2%)	368 (24.3%)	28,510 (80.7%)
At least one “other” diabetes ICD-10 code	26 (2.0%)	241 (0.8%)	21 (0.4%)	35 (2.3%)	253 (0.7%)
>50% type 1 ICD-10 codes	1,172 (92.4%)	93 (0.3%)	50 (1.0%)	1,255 (85.9%)	60 (0.2%)
>=50% type 2 ICD-10 codes	32 (2.5%)	25,971 (85.5%)	2,614 (50.0%)	130 (8.6%)	28,487 (80.6%)
No type 1 or type 2 ICD-10 codes	65 (5.1%)	4,309 (14.2%)	2,555 (49.0%)	129 (8.5%)	6,800 (19.2%)

Type 1 ICD-9 codes = 250.x1, 250.x3. Type 2 ICD-9 codes = 250.x0, 250.x2.

Type 1 ICD-10 codes = E10.xx. Type 2 ICD-10 codes = E11.xx.

“Other” diabetes ICD-10 codes = E08.xx, E09.xx, E13.xx.

Percentage of type 1 codes was calculated as: # type 1 codes / (# type 1 codes + # type 2 codes).

Percentage of type 2 codes was calculated as: # type 2 codes / (# type 1 codes + # type 2 codes).