Table 4—

Overview of studies addressing interobserver agreement on thoracic computed tomography(CT) in various forms of pulmonary fibrosis

First author [Ref.]	Year	Interobserver agreement κ coefficient	Study population	Subjects n	Observers n	Comments
Grenier 10	1991	0.64–0.78	Sarcoidosis	53	3	Definition of IPF unclear
			Pulmonary fibrosis	33
			Histiocytosis X	17
			Other ILD	37
Wells 19	1993	0.58–0.76	Systemic sclerosis	35	2	Interobserver agreement for grading CT appearance and change in nature and extent of disease
			IPF	21
Collins 8	1994	0.48	Systemic sclerosis	63	4	Interobserver agreement for CT pattern type
			IPF	63
Kazerooni 20	1997	0.51–0.83	UIP; DIP	24; 1	4	Interobserver agreement for pattern type in different lobes
MacDonald 9	2001	0.40	NSIP	21	4	Interobserver agreement for NSIP and UIP
			UIP	32
Hunninghake 7	2001	0.54	IPF	54	4	Interobserver agreement for IPF versus non-IPF; criteria for IPF diagnosis not mentioned
			Non-IPF	37
Flaherty 3	2003	0.43	NSIP	23	2	Interobserver agreement for NSIP and UIP
			UIP	73
Aziz 21	2004	0.50	DPLD	131	11	Interobserver agreement for first-choice diagnosis of IPF
Present study		0.40	UIP	156	3	Interobserver agreement for IPF versus non-IPF; IPF patients included following ATS/ERS criteria
			Non-UIP	23

ILD: interstitial lung disease; IPF: idiopathic pulmonary fibrosis; UIP: usual interstitial pneumonia; DIP: desquamative interstitial pneumonia; NSIP: nonspecific interstitial pneumonia; DPLD: diffuse parenchymal lung disease; ATS: American Thoracic Society; ERS: European Respiratory Society.