Validity of Claims Diagnosis Codes for Cardiovascular Diseases in Diabetes Patients in Japanese Administrative Database

Figures & data

Table 1 Definition of Primary and Secondary Outcomes for Administrative Claims and EMR

Outcome: Diagnosis Name	Definition of Outcome for Administrative Claims^a	Definition of Outcome for EMR (Gold Standard)
Primary 1: Congestive heart failure 1	I50	I50
Primary 2: Congestive heart failure 2	I50, I11.0, I13.0, or I13.2	I50, I11.0, I13.0, or I13.2
Primary 3: Ischemic stroke	I63	I63
Primary 4: Hemorrhagic stroke	I60, I61, or I62	I60, I61, or I62
Primary 5: Any type of stroke	I60, I61, I62, I63, or I64	I60, I61, I62, I63, or 64
Primary 6: End stage renal disease	1) ^beGFR<15 mL/min/m^2, at least 2 measurements separated by ≥30 days (≤12 months) OR 2) ≥2 of the following diagnosis or procedure codes (either in/out-patient), separated by ≥30 days; Diagnoses: N18.5, N18.6; Procedures: Hemodialysis J038, C102-2; Peritoneal dialysis J042, C102, C155, K635-3 OR 3) Kidney transplant, defined as ≥1 of the following diagnosis or procedure codes (in/out-patient): Diagnoses: Z94.0, T86.1; Procedures: Transplant of kidney K780-2	N17.0, N17.1, N17.2, N17.8, N17.9, N18.4, N18.5, N18.6, Z94.0, T86.1 or eGFR<15 mL/min/m^2, at least 2 measurements separated by ≥30 days (≤12 months)
Primary 7: Myocardial infarction	I21, or I22	I21, or I22
Primary 8: Death	Record of death	Record of death
Secondary: Mild or moderate chronic kidney disease	N18 and ^beGFR values 30–59 mL/min/m^2 separated by >30 days	N18

Notes: ^aAdministrative claims: DPC claims for primary outcomes and any administrative claim for secondary outcome. ^beGFR values recorded in EMR were used. Codes for diagnoses are based on ICD-10.

Abbreviations: DPC, diagnostic procedure combination; eGFR, estimated glomerular filtration rate; EMR, electronic medical record; ICD-10, International Classification of Diseases, 10th Revision.

Figure 1 Flow diagram (A) and demographics (B) for identification of study population.

Notes: ^aAdministrative claim, any of administrative claim at least one. *Indicates study population.
Abbreviations: EMR, electronic medical record; SD, standard deviation; T2D, type 2 diabetes.

Table 2 Number and Demographics of Patients for Each Outcome Based on the Definition for Administrative Claims

Outcome	Diagnosis Name	Number of Patients	Average (SD) of Age	Female (%)
Primary 1	Congestive heart failure 1	5,404	79.1 (11.4)	42.6%
Primary 2	Congestive heart failure 2	5,502	79.1 (11.4)	42.8%
Primary 3	Ischemic stroke	4,723	75.9 (11.2)	36.5%
Primary 4	Hemorrhagic stroke	2,027	73.3 (12.8)	41.8%
Primary 5	Any type of stroke	6,678	75.1 (11.8)	38.2%
Primary 6	End stage renal disease	3,722	69.6 (12.6)	32.7%
Primary 7	Myocardial infarction	1,700	71.1 (12.2)	26.1%
Primary 8	Death	10,815	77.8 (11.2)	36.9%
Secondary	Mild or moderate chronic kidney disease	8,938	71.9 (12.4)	32.8%

Abbreviation: SD, standard deviation.

Table 3 PPV for Definition of Each Outcome

Outcome	Diagnosis Name	N^a	True Events^b	PPV	95% CI of PPV
					Upper	Lower
Primary 1	Congestive heart failure 1	7,392	7,068	95.6%	96.1%	95.2%
Primary 2	Congestive heart failure 2	7,522	7,199	95.7%	96.2%	95.2%
Primary 3	Ischemic stroke	5,046	4,322	85.7%	86.6%	84.7%
Primary 4	Hemorrhagic stroke	2,117	1,904	89.9%	91.2%	88.7%
Primary 5	Any type of stroke	7,151	6,359	88.9%	89.7%	88.2%
Primary 6	End stage renal disease	3,722	2,510	67.4%	68.9%	65.9%
Primary 7	Myocardial infarction	1,738	1,368	78.7%	80.6%	76.8%
Primary 8	Death	10,815	8,683	80.3%	81.0%	79.5%
Secondary	Mild or moderate chronic kidney disease	8,938	8,309	93.0%	93.5%	92.4%

Notes: ^aN, number of events (number or hospitalizations or patients) defined by administrative claims (denominator), ^bTrue events, number of events defined by EMR (numerator).

Abbreviations: CI, confidence interval; PPV, positive predictive value.