EmPHasis-10: Development of a health-related quality of life measure in pulmonary hypertension

The aim of this study was to develop a measure of the impact of pulmonary hypertension (PH) on health-related quality of life (HRQoL) as there is a need for a short, validated instrument that can be used in routine clinical practice. Interviews were conducted with 30 PH patients to derive 32 statements, which were presented as a semantic differential six-point scale (0-5), with contrasting adjectives at each end. This item list was completed by patients attending PH clinics across the UK and Ireland. Rasch analysis was applied to identify items fitting a uni-dimensional model. 226 patients (mean age 55.6±14 years; 70% female) with PH (82% had pulmonary arterial hypertension) completed the study questionnaires. 10 of the 32 items demonstrated fit to the Rasch model (Chi-squared 16; p>0.05) and generated the emPHasis-10 questionnaire. Test-retest (intraclass correlation coefficient 0.95, n=33) and internal consistency (Chronbach's α=0.9) were strong. emPHasis-10 scores correlated consistently with other relevant measures and discriminated subgroups of patients stratified by World Health Organization functional class (ANOVA F=1.73; p