Tables
- TABLE 1
Incidence of idiopathic pulmonary fibrosis (IPF) in studies using large databases
First author [ref.] Year Location Years studied Data source type Condition studied Case definition Population demographics Incidence per 100 000 per year# Rate type Large database studies Europe Maher [7]¶ 2013 UK 2000–2012 Nationwide primary care database (CPRD) IPF NA NA 8.65 Crude Navaratnam [8] 2011 UK 2000–2008 Nationwide primary care database (THIN) IPF ICD-9 codes for IFA (515) and PF (516.3) Overall population of the UK 7.44 Crude Kornum [9] 2008 Denmark 1995–2000 Nationwide health database IPF (and ILD) ICD-10 J84.1 Overall population of Denmark 7.27
4.17Crude
Age-adjusted2001–2005 Nationwide health database IPF (and ILD) ICD-10 J84.1 5.28
2.91Crude
Age-adjustedGribbin [10] 2006 UK 1991–2003 Nationwide primary care database (THIN) IPF Read codes for CFA, IFA Overall THIN population 4.6 Crude North America Ley [11] 2017 NC, USA 2000–2014 Health insurance plan database IPF ICD-9 code 516.3, or ICD-9-CM code 516.31 Overall health insurance plan population 6.8 (overall)
3.1 (per 100 000 person-years)PPV-corrected Esposito [12] 2015 USA 2006–2012 Nationwide HealthCore Integrated Research Database IPF ICD-9-CM code 516.3 Health plan members; age-adjusted value applicable to overall US population 31.9 (broad case definition)
14.6 (per 100 000 person-years)Age-adjusted, PPV-corrected Raghu [13] 2014 USA 2001–2011 Medicare database; 5% random sample IPF ICD-9-CM 516.3 and 515
ICD-9-CM 516.3Medicare population aged ≥65 years 93.7 (overall)
31.1–43.0 (broad)
15.9–31.1 (narrow)Crude, patients aged >65 years
Algorithm-defined exclusions, patients aged >65 yearsFernández Pérez [14] 2010 Olmsted County, MN, USA 1997–2005 Rochester Epidemiology Project (medical record linkage system for healthcare providers) IPF ICD-9 code 516.3
Hospital International Classification of Diseases-Adapted codes 517 and 519Olmsted County population aged ≥50 years; data adjusted for applicability to overall US white population 8.8 (narrow)
17.4 (broad)Age-adjusted, sex-adjusted Ehrlich [15] 2010 CA, USA 1996–2005 Health insurance plan database IPF
PFICD-9 516.3/515 Health plan population; data adjusted for applicability to overall US population aged ≥18 years 9 (non-diabetics)
14 (diabetics)Crude
Age-adjusted, by diabetic statusRaghu [16] 2006 USA 1996–2000 Health claims database IPF ICD-9 516.3 Health claims database population; data adjusted for applicability to overall US population 16.3 (broad)
6.8 (narrow)Age-adjusted South America Rufino [17]¶ 2013 Brazil 1996–2010 Ministry of Health data IPF ICD-10 J84.1 0.48 Crude Asia Han [18]¶ 2013 South Korea 1992–2010 Healthcare claims from insurance medical cohort IPF NA NA 4.16 (broad)
1.84 (narrow)Crude, patients >30 years Lai [19] 2012 Taiwan 1997–2007 Health insurance database/ government records IPF ICD-9 516.3 Population of the Taiwan National Health Insurance database 1.4 (broad)
1.2 (narrow)Crude Natsuizaka [20] 2014 Hokkaido prefecture, Japan 2003–2007 Ministry of Health, Labor and Welfare data IPF ATS/ERS consensus classification Overall population of Hokkaido 2.23 Crude International Classification of Diseases (ICD) codes are presented as ICD-nth revision, clinical modification (CM). ICD-10 code J84.1 is currently the most specific code for IPF but may include other idiopathic interstitial pneumonia (IIP). ICD-9 code 516.3 is roughly equivalent; code 515 is “post-inflammatory fibrosis”. Broad criteria were: one or more claims with a diagnostic code for IPF, but no claims for another diagnostic code for interstitial lung disease (ILD). Narrow criteria were: as for broad criteria, with a relevant diagnostic test on or before their first diagnosis date. Broad and narrow criteria were based on the 2002 American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines [21]. Probable cases were based on criteria from [22]: received a diagnosis of ILD from a rheumatologist or pulmonary physician; or ILD was the primary discharge diagnosis. Definite cases had a confirmatory diagnosis within 90 days. CPRD: Clinical Practice Research Datalink; NA: not available; THIN: The Health Improvement Network; IFA: idiopathic fibrosing alveolitis; PF: pulmonary fibrosis; CFA: cryptogenic fibrosing alveolitis; PPV: positive-predictive value; IIP: idiopathic interstitial pneumonia; IPF: idiopathic pulmonary fibrosis. #: average incidence for the time period available; latest incidence stated where no average was given, incidence extrapolated from ILD data where percentage of IPF cases was given; ¶: abstract only. Reproduced and modified from [23] with permission.
- TABLE 2
Characteristics of unclassifiable interstitial lung disease patients
Country Years Unclassifiable n/total N (%) With surgical biopsy % Male % Age years FVC
%DLCO
%Spain 1995–2004 73/500 (14.6) 26.2 47 66.7±13.6 China 1999–2009 38/251 (15.1) 100 Spain 2000–2001 26/511 (5.1) 22.7 USA 2000–2011 132/1370 (9.6) 31 53 67.8±12.9 69.0±22.1 47.6±19.7 Denmark 2003–2009 62/431 (14) 34 45 59.3±14.5 73.7±22.8 55.8±21.4 Australia 2011–2013 23/232 (9.9) Data are presented as mean±sd, unless otherwise stated. Blank cells represent data that were not reported. FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide. Reproduced and modified from [39] with permission.
