Table 4 Positive predictive value (PPV) of code-based algorithms for IPF case finding in routinely-collected health data

DA1

Aurum

• Any broad code in Aurum

9,498

6,113

64.3%

(63.3–65.3)

53.5%

(52.9–54.1)

DA2

Aurum and HES DID

• Any broad code in Aurum

and

• Evidence of HRCT of thorax at any time

and

• No other known causes of ILD recorded in Aurum^a

4,721

3,187

67.5%

(66.1–68.8)

28.2%

(27.3–29)

DA3

Aurum

• Any narrow code in Aurum

1,828

1,370

74.9%

(72.8–76.9)

12.1%

(11.5–12.7)

DA4

Aurum and HES DID

• Any narrow code in Aurum

and

• Evidence of HRCT of thorax at any time

and

• No other known causes of ILD recorded in Aurum^a

891

706

79.2%

(76.4–81.8)

6.3%

(5.8–6.7)

DA5

HES-APC

• ICD-10 codes J84.1, J84.8 or J84.9 as primary or secondary discharge diagnosis in either the first or any subsequent “episodes” within a hospital spell

10,714

6,651

62.0%

(61.1–63.0)

57.0

(56.4–57.7)

DA6

HES-APC and HES DID

• ICD-10 codes J84.1, J84.8 or J84.9 as primary or secondary discharge diagnosis in the first or any subsequent “episode” within a hospital spell

and

• Evidence of HRCT of thorax at any time

2,985

2,379

79.7%

(78.2–81.1)

21.0%

(20.3–21.8)

DA7

Aurum and HES-APC

• Any broad code in Aurum

and

• ICD-10 codes J84.1, J84.8 and J84.9 as primary or secondary discharge diagnosis in either the first or any subsequent “episodes” within a hospital spell

5,488

4,304

78.4%

(77.3–79.5)

38.1%

(37.2–39.0)

DA8

Aurum and HES-APC

• Any narrow code in Aurum

and

• ICD-10 codes J84.1, J84.8 or J84.9 as primary or secondary discharge diagnosis in the first or any subsequent “episode” within a hospital spell

1,190

974

81.8%

(79.5–84.0)

8.6%

(8.1–9.1)