Background
Methods
Data sources
Data set | Coverage | Key information (including coding system) |
---|---|---|
Primary care
| ||
CPRD Aurum | Start of patient GP registration – c. October 2020 | Symptoms and clinical diagnoses, demographic characteristics, vaccination history, lifestyle and behaviours (e.g. smoking history), laboratory test results, prescriptions, referrals to secondary care (SNOmed codes, READ codes) |
Linked data sets
| ||
ONS Death registration data | 1998–2020 | Date, place and cause of death including underlying and contributory causes of death (ICD-10) |
Hospital Episode Statistics (HES) | ||
Admitted Patient Care (APC) | 1997–2020 | Details of all admissions to NHS hospitals in England (including acute, mental and primary care trust hospitals) including clinical diagnoses (ICD-10) and procedures performed (OPCS) |
Diagnostic Imaging Dataset (DID) | 2012–2020 | Type of imaging performed (CT, X-ray, MRI) and body area imaged (e.g. chest) |
Study design and population
Case definitions
CPRD Aurum
HES/ONS data
Risk factors and comorbidities
Analysis
Descriptive analysis
Concordance in the recording of IPF across Aurum, HES-APC and ONS
Diagnostic algorithms and validation
Diagnostic algorithm | Data source (Aurum and/or HES) | Description |
---|---|---|
DA1 | Aurum | • Any broad code in Aurum |
DA2 | Aurum and HES DID | • Any broad code in Aurum and • No other known causes of ILD recorded in Auruma and • Evidence of HRCT of thorax at any time in HES DID |
DA3 | Aurum | • Any narrow code in Aurum |
DA4 | Aurum and HES DID | • Any narrow code in Aurum and • No other known causes of ILD recorded in Auruma and • Evidence of HRCT of thorax at any time in HES DID |
DA5 | HES-APC | • ICD-10 codes J84.1, J84.8 or J84.9 as primary or secondary discharge diagnosis in any “episode” within a hospital spell |
DA6 | HES-APC and HES DID | • ICD-10 codes J84.1, J84.8 or J84.9 as primary or secondary discharge diagnosis in any “episode” within a hospital spell and • Evidence of HRCT of thorax at any time |
DA7 | Aurum and HES-APC | • Any broad code in Aurum and • ICD-10 codes J84.1, J84.8 or J84.9 as primary or secondary discharge diagnosis in any s “episodes” within a hospital spell |
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 any “episode” within a hospital spell |
Results
Coding practices in primary care over time
Concordance
Study population
Characteristic | ONS % of total (n) unless otherwise stated | Aurum % of total (n) unless otherwise stated | HES-APC % of total (n) unless otherwise stated |
---|---|---|---|
Total cohort |
11,295 (100%)
|
9,948 (100%)
|
10,714 (100%)
|
Demographic
| |||
Median (IQR) age in years | 77 (10.3) | 77 (13) | 77 (14) |
≥ 65 years | 90.0% (n = 10,176) | 86.2% (n = 8,191) | 85.3% (n = 9,145) |
Male | 63.0% (n = 7,123) | 63.2% (n = 6,011) | 60.7% (n = 6,512) |
Smoking history (ever/current) | 48.9% (n = 5,529) | 66.2%(n = 6,288) | 65.6% (n = 7,030) |
Comorbidities
| |||
COPD | 18.2% (n = 2,060) | 19.0% (n = 1,806) | 20.9% (n = 2,240) |
Asthma (in past 2 years) | 6.93% (n = 784) | 10.1% (n = 959) | 10.3% (n = 1,111) |
Lung cancer | 3.0% (n = 348) | 2.1% (n = 206) | 2.8% (n = 305) |
Ischemic stroke | 13.4%(n = 1,513) | 12.0% (n = 1,142) | 13.2% (n = 1,418) |
Heart failure | 17.9% (n = 2,024) | 17.1% (n = 1,629) | 17.6% (n = 1,889) |
Ischemic heart disease | 13.4% (n = 1,523) | 13.6% (n = 1,300) | 13.4% (n = 1,441) |
Myocardial infarction | 13.1% (n = 1,481) | 13.3% (n = 1,267) | 13.2% (n = 1,414) |
Gastroesophageal reflux | 17.8% (n = 2,012) | 17.6% (n = 1,677) | 17.6% (n = 1,892) |
ONS, Aurum and HES-APC
Sensitivity analyses
Algorithm validation
Diagnostic algorithm | Data source | Description | No. of patients found | No. of patients meeting gold standard | PPV (95% CI) | Sensitivity (95% CI) |
---|---|---|---|---|---|---|
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 Auruma | 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 Auruma | 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) |
Aurum code-based algorithms
Aurum-plus-HES APC algorithms
Demographic and clinical characteristics
Characteristic | DA1 N = 9,498 % of total (n) unless otherwise stated | DA3 N = 3,449 % of total (n) unless otherwise stated | DA6 N = 2,069 % of total (n) unless otherwise stated | DA7 N = 5,488 % of total (n) unless otherwise stated |
---|---|---|---|---|
Demographic
| ||||
Median (IQR) age in years | 77 (13) | 76(14) | 76(14) | 76 (14) |
≥ 65 years | 86.2% (n = 8,191) | 82.9% (n = 1,516) | 84.4% (n = 2,522) | 83.7% (n = 4,593) |
Male | 63.2% (n = 6,011) | 63.8% (n = 661) | 64.4% (1,922) | 62.5% (n = 3,434) |
Median (IQR) survival in years | 2.0 (3.7) | 2.6 (4.8) | 1.8 (3.5) | 2.2 (3.9) |
Smoking history (ever/current) | 66.2%(n = 6,288) | 62.4%(n = 1,1420 | 68.5(2,046) | 66.4% (n = 3,642) |
Comorbiditie
s
| ||||
COPD | 19.0% (n = 1,806) | 14.7% (n = 269) | 17.8% (n = 532) | 16.1% (n = 886) |
Asthma (in past 2 years) | 10.1% (n = 959) | 7.9% (n = 146) | 8.9% (n = 268) | 9.4% (n = 518) |
Lung cancer | 2.1% (n = 206) | 1.5% (n = 28) | 2.3% (n = 70) | 1.6% (n = 85) |
Ischemic stroke | 12.0% (n = 1,142) | 10.1% (n = 185) | 12.4% (n = 370) | 11.8% (n = 645) |
Heart failure | 17.1% (n = 1,629) | 13.6% (n = 249) | 16.3% (n = 489) | 16.4% (n = 899) |
Ischemic heart disease | 13.6% (n = 1,300) | 11.8% (n = 217) | 14.4% (n = 430) | 13.3% (n = 735) |
Myocardial infarction | 13.3% (n = 1,267) | 11.2% (n = 206) | 12.4% (n = 370) | 12.7% (n = 693) |
Gastroesophageal reflux | 17.6% (n = 1,677) | 15.8% (n = 289) | 20% (n = 597) | 18.2% (n = 1,002) |