Exploratory and confirmatory factor analysis of emPHasis-10: The health-related quality-of-life measure in pulmonary hypertension.

The emPHasis-10 is a health-related quality of life (HRQoL) unidimensional measure developed specifically for adults with pulmonary hypertension. The tool has excellent psychometric properties and is well used in research and clinical settings. Its factor structure has not been examined, which may help to identity a complimentary approach to using the measure to examine patient functioning. We performed an exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) on a data set collected from 263 adults with PH recruited from a community setting. The EFA suggested the emPHasis-10 consists of three underlying latent variables, which based on the loading of items, were termed "fatigue" (Items 3, 4, and 5), "independence" (Items 7, 8, 9, and 10), and "breathlessness" (Items 1, 2, and 6). All factors were found to have good internal consistency. "Independence" accounted for most of the variance (29%), followed by "breathlessness" (22%) and "fatigue" (19%). The CFA looked to confirm the fit of a three-factor model. A higher-order model was found to be the best fit consisting of HRQoL as a superordinate factor, for which the association between this factor and the 10 items was mediated through the three latent factors. Further analyses were performed testing the validity of the latent variables revealing all were significantly correlated with self-reported measures of depression, anxiety, health-anxiety, and dyspnea. Our analyses support the emPHasis-10 as a measure of HRQoL, while also proposing the clinical utility of examining the three emergent factors, which could be used to glean additional insight into the respondent's functioning and inform care.