Psychometric Validation of the Simplified Chinese Version of the Dyspnoea-12 Questionnaire for Patients with Primary Lung Cancer

Purpose: The simplified Chinese version of the Dyspnoea-12 Questionnaire (D-12) has not yet been translated and validated for patients with primary lung cancer. This study aimed to evaluate the psychometric properties of the simplified Chinese version of the D-12 for patients with primary lung cancer. Methods: This study analysed the baseline data of a randomised controlled trial that used an inspiratory muscle training intervention for patients with thoracic malignancies. The original English version of the D-12 was translated into simplified Chinese according to standard instrument translation and adaptation procedures. The internal consistency reliability of the D-12 was determined by calculating Cronbach’s alpha coefficients. The convergent validity of the D-12 was evaluated by Spearman’s correlation with the Borg CR-10 Scale, Numerical Rating Scale (NRS), Hospital Anxiety and Depression Scale (HADS), and Saint George’s Respiratory Questionnaire (SGRQ). Blood oxygen level, the 6-minute walk test distance, alcohol use, surgery type, cancer stage, exercise level, and educational background were identified to evaluate their discriminating performance. Results: The analysis included 196 participants. The Cronbach’s alpha coefficients for the full D-12 and its physical and emotional function subscales were 0.83, 0.74, and 0.92, respectively. Significantly positive associations were found between the D-12 scores and the Borg CR-10 Scale, the NRS, the HADS, and SGRQ scores (p < 0.01). The participants with insomnia (p < 0.01) and who did not use alcohol (p = 0.019) reported significantly higher D-12 total scores compared with their respective counterparts. The participants at different cancer stages (p < 0.01) and those who had undergone different surgeries (p = 0.033) reported significantly different D-12 total scores. Conclusions: The D-12 simplified Chinese version demonstrated very good psychometric properties and high acceptability in patients with primary lung cancer.