Bariatric surgery is usually considered when other weight loss efforts have failed. Eligibility criteria were established by the 1991 National Institutes of Health Consensus Development Conference Panel and continue to be the most widely accepted criteria.
Exclusion of other known causes of ILD such as certain drug toxicities, environmental exposures, and connective tissue diseases
Abnormal pulmonary function studies that include evidence of restriction (reduced VC, often with an increased FEV1/FVC ratio) and impaired gas exchange [increased P(A–a)O2, decreased PaO2 with rest or exercise or decreased DLCO]
Bibasilar reticular abnormalities with minimal ground glass opacities on HRCT scans
Transbronchial lung biopsy or BAL showing no features to support an alternative diagnosis