Validity and reliability testing of the Thai version of the emPHasis-10 questionnaire for patients with pulmonary arterial hypertension

The emPHasis-10 questionnaire is a specific tool for assessing health-related quality of life (HRQoL) in pulmonary arterial hypertension (PAH). We conducted the cross-cultural validation of the Thai emPHasis-10 questionnaire with an assessment of its validity and reliability in patients with PAH. The original English emPHasis-10 questionnaire was translated into Thai using a forward and backward translation process. Content validity was assessed by five experts using the Item-Objective Congruence (IOC) index, and reliability was assessed by 20 patients with PAH using Cronbach’s alpha for internal consistency and the intraclass correlation coefficient (ICC) for test-retest reliability. All patients had a confirmed diagnosis of PAH by right heart catheterization, and baseline clinical and hemodynamic characteristics were collected. For Thai emPHasis-10 questionnaire, the IOC value was 0.94 (range 0.80 to 1.00). Among all patients, 19 (95%) were female, and the mean age±standard deviation (SD) was 46.8 ± 14.2 years, and 17 (85%) were at World Health Organization functional class II. Idiopathic PAH, PAH associated with connective tissue disease, and PAH associated with congenital heart disease were classified in 7, 6, and 7 patients, respectively. The mean baseline mean pulmonary arterial pressure and pulmonary vascular resistance were 55.1 ± 19.5 mmHg and 13.1 ± 8.4 Wood units, respectively. The mean ± SD of the Thai emPHasis-10 score was 18 ± 10. Cronbach’s alpha and ICC values were 0.925 and 0.996 (95% confidence interval 0.991 to 0.999), respectively. The Thai emPHasis-10 questionnaire has acceptable validity and reliability. This tool can be used as an additional measure for PAH severity assessment.