Table 2.

IPF prevalence estimates per country

Country	Study	Publication year	Mean unadjusted prevalence (per 10,000)	Adjusted prevalence (per 10,000)	95% CI Adjusted prevalence (per 10,000)	Rare disease threshold (per 10,000)	Rare disease threshold met?
Asia–Pacific
Japan	Kondoh et al. [42]	2016	0.59	0.89	(0.51, 1.55)	< 50,000 casesa [25]	NA
	Natsuizaka et al. [45]	2014	1.00
	Combined		0.79
South Korea	Kim et al. [41]	2017	3.52	4.51	(2.99, 6.79)	< 20,000 casesa [26]	NA
	Lee et al. [44]	2016	3.89
	Combined		3.70
Taiwan	Lai et al. [43]	2012	0.49	0.57	(0.34, 0.94)	1 [27]	Yes
Europe
Denmark	Hyldgaard et al. [39]	2014	1.01	1.17	(0.56, 2.44)	1–2 [28]	Yes (upper CI out of bounds)
Finland	Kaunisto et al. [40]	2015	0.86	0.65	(0.36, 1.18)	5 [29]	Yes
France	Duchemann et al. [35]	2017	0.82	0.94	(0.44, 1.99)	5 [29]	Yes
Greece	Karakatsani et al. [52]	2009	0.34	0.33	(0.21, 0.53)	5 [29]	Yes
Italy	Agabiti et al. [33]	2014	2.56	2.37	(1.38, 4.09)	5 [29]	Yes
	Harari et al. [37]	2016	2.12
	Combined		2.46
Poland	Szafrański [50]	2012	2.56	2.51	(1.55, 4.05)	5 [29]	Yes
United Kingdom	Strongman et al. [13]	2018	1.16	0.78	(0.38, 1.63)	5 [29]	Yes
North America
Canada	Hopkins et al. [38]	2016	2.00	2.98	(1.7, 5.19)	5 [30]	Yes (upper CI out of bounds)
	Tarride et al. [12]	2018	7.27
	Combined		2.98
United States	Fernández Pérez et al. [11]	2010	2.81	2.4	(1.33, 4.34)	< 200,000a [31]	Yes
	Raghu et al. [47]	2014	11.1
	Raghu et al. [46]	2016	0.67
	Combined		1.37

CI confidence interval, IPF idiopathic pulmonary fibrosis, NA not applicable

^aNumber of cases provided rather than threshold