Table 1.

Comparison between 2007 and 2016 criteria of AE of IPF

	IPF diagnosis	Course	HRCT findings	Exclusion
2007 guideline	Previous or concurrent diagnosis	Less than1 month	New bilateral GGO and/or consolidation on a background pattern of UIP pattern	Exclusion of alternative etiologies, such as infection, heart failure, and pulmonary embolism; BAL is required
2016 guideline	Previous or concurrent diagnosis	Typically less than 1 month	New bilateral GGO and/or consolidation on a background pattern of UIP pattern	Deterioration not fully explained by heart failure or fluid overload

AE: acute exacerbation; IPF: idiopathic pulmonary fibrosis; HRCT: high resolution computed tomography; GGO: ground-glass opacity; UIP: usual interstitial pneumonia; BAL: broncho-alveolar lavage