Reliability and validity of an arabic version of the dyspnea-12 questionnaire for Saudi nationals with chronic obstructive pulmonary disease

BACKGROUND: Dyspnea is a distressing symptom experienced by people with chronic obstructive pulmonary disease (COPD). The dyspnea-12 (D-12) questionnaire comprises of 12 items and assesses the quality of this symptom, its severity and the emotional response. The original (English) version of the D-12 is reliable and valid for the measurement of dyspnea in pulmonary diseases. AIM: To translate the D-12 into Arabic and determine whether this version is reliable and valid in Saudi nationals with COPD. METHODS: The D-12 was translated into Arabic version and reviewed by an expert panel before being back-translated into English. The Arabic version was administered to five patients with COPD to test whether it was easily understood after which a final Arabic version was produced. Thereafter, 40 patients with COPD (aged 63 ΁ 9 years; 33 [82.5%] males; forced expiratory volume in one second (FEV 1) 47 ΁ 16% predicted) completed the D-12, the COPD Assessment Test (CAT) and the Chronic Respiratory Disease Questionnaire (CRDQ). Lung function and 6-minute walk distance were also measured. The D-12 was re-administered two weeks later. RESULTS: The Arabic version of the D-12 demonstrated good reliability over the two administration (intraclass correlation coefficient = 0.94, P = 0.01). Strong associations were demonstrated between the (1) total score for the D-12 and the CAT, (2) quality sub-score of the D-12 and the CAT and (3) emotional response sub-score of the D-12 and emotional function domain of the CRDQ (r ≥ 0.6, all P < 0.01). CONCLUSION: The Arabic version of the D-12 is a reliable and valid instrument in Saudi nationals with COPD.