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In this study, we aimed to determine the validity and reliability of the Dyspnea-12 questionnaire (D-12) for the assessment of breathlessness in patients with interstitial lung disease (ILD).

A total of 101 patients with ILD completed the D-12 (scale range, 0-36, with a high score indicating worse dyspnea), Medical Research Council (MRC) dyspnea scale, St. George Respiratory Questionnaire (SGRQ), and Hospital Anxiety and Depression Scale (HADS) at baseline, and 84 patients completed the D-12 and a global health transition score at follow-up 2 weeks later. D-12 psychometric properties, including floor and ceiling effects, internal consistency, test-retest reliability, and construct validity were examined.

The D-12 showed good internal consistency (Cronbach α, 0.93) and repeatability (intraclass correlation coefficient, 0.94). Its scores were significantly associated with MRC grade (r = 0.59; P < …