RT Journal Article SR Electronic T1 A diagnostic model for chronic hypersensitivity pneumonitis JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 951 OP 954 DO 10.1136/thoraxjnl-2016-208286 VO 71 IS 10 A1 Johannson, Kerri A A1 Elicker, Brett M A1 Vittinghoff, Eric A1 Assayag, Deborah A1 de Boer, Kaïssa A1 Golden, Jeffrey A A1 Jones, Kirk D A1 King, Talmadge E A1 Koth, Laura L A1 Lee, Joyce S A1 Ley, Brett A1 Wolters, Paul J A1 Collard, Harold R YR 2016 UL http://thorax.bmj.com/content/71/10/951.abstract AB The objective of this study was to develop a diagnostic model that allows for a highly specific diagnosis of chronic hypersensitivity pneumonitis using clinical and radiological variables alone. Chronic hypersensitivity pneumonitis and other interstitial lung disease cases were retrospectively identified from a longitudinal database. High-resolution CT scans were blindly scored for radiographic features (eg, ground-glass opacity, mosaic perfusion) as well as the radiologist's diagnostic impression. Candidate models were developed then evaluated using clinical and radiographic variables and assessed by the cross-validated C-statistic. Forty-four chronic hypersensitivity pneumonitis and eighty other interstitial lung disease cases were identified. Two models were selected based on their statistical performance, clinical applicability and face validity. Key model variables included age, down feather and/or bird exposure, radiographic presence of ground-glass opacity and mosaic perfusion and moderate or high confidence in the radiographic impression of chronic hypersensitivity pneumonitis. Models were internally validated with good performance, and cut-off values were established that resulted in high specificity for a diagnosis of chronic hypersensitivity pneumonitis.