TABLE 1.

Characteristics of studies identified

Characteristics	Details
Study type	154 cohort studies (64% retrospective design)#
	16 RCTs
Publication year	Before 1990: n=6
	1990–1999: n=17
	2000–2009: n=38
	Since 2010: n=109
Location	Europe: n=60
	Asia: n=47
	American continent: n=45
	Australia: n=5
IPF diagnostic criteria	2011 ATS/ERS/JRS/ALAT guideline: n=41 2000 ATS/ERS international consensus statement: n=57
	Other: n=72
Design	Cohort study#
	Prospective design (n=55): 73% single-centre, 20% multicentre, 5% registry/database, 2% unclear
	Retrospective design (n=98): 79% single-centre, 12% multicentre, 8% registry/database, 1% unclear
	RCT (n=16): all multicentre trials
Participant number	Cohort study#
	Prospective design (n=55): median (range) 44 (7–588)
	Retrospective design (n=98): median (range) 81 (11–13 615)
	RCT (n=16): median (range) 94 (28–423)¶
Duration	Cohort study#,+
	Prospective design (n=55): 40% between 1 year and <2 years; 33% between 2–5 years; 13% ≥5 years
	Retrospective design (n=98): 43% between 1 year and <2 years; 12% between 2–5 years; 10% ≥5 years
	RCT (n=16): all with a study duration of 1 year and <2 years

IPF: idiopathic pulmonary fibrosis; ATS: American Thoracic Society; ERS: European Respiratory Society; JRS: Japanese Respiratory Society; ALAT: Latin American Thoracic Association; RCT: randomised controlled trial. ^#: not including Mura et al. [110]: a single-centre study with both prospective (n=70) and retrospective (n=68) cohorts, with a study duration ≥3 years; ^¶: number of participants in the placebo arm only; ^+:: all studies had a study duration ≥1 year. Some studies provided mean or median follow-up duration which could not be incorporated into the table.