caa a22 4500 606177876 CHVBK 20210128100754.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s11136-014-0839-9 doi (NATIONALLICENCE)springer-10.1007/s11136-014-0839-9 Energy, fatigue, or both? A bifactor modeling approach to the conceptualization and measurement of vitality [Elektronische Daten] [Nina Deng, Rick Guyer, John Ware Jr.] Purpose: Vitality is an important domain reflecting both the physical and emotional components of health-related quality of life. Because of its complexity, it has been defined and measured both broadly and narrowly. We explored the dimensionality of a very comprehensive item bank hypothesized to measure vitality and its related concepts. Methods: Secondary analyses were conducted using the responses of 1,343 adults representative of the US general population to Internet-based surveys including 42 items compiled from multiple scales (e.g., SF-36 Vitality, PROMIS-Fatigue), covering a broad range of vitality-related content areas (energy, fatigue, and their interference with physical, mental, social activities, and quality of life). Exploratory and confirmatory factor models were evaluated independently using split-half samples. Bifactor model was used to assess the essential unidimensionality of the items, in comparison with traditional unidimensional, multidimensional, and hierarchical models. Method effects of a common scale or phrase were modeled via correlating errors. Results: The exploratory factor analysis identified one dominant factor. The confirmatory factor analysis identified a best-fitting (CFI=0.964, RMSEA=0.084) bifactor model with one general (vitality) and two group (energy and fatigue) factors, explaining 69, 3, and 4% of total variance. Correlating errors accounting for the method effects were important in identifying the substantive dimensionality of the items. Conclusions: The bifactor model proved to be useful for evaluating the dimensionality of a complex construct. Results supported conceptualizing and measuring vitality as a unidimensional energy-fatigue construct. We encourage future studies comparing practical implications of measures based on the broader and narrower conceptualizations of vitality. Springer International Publishing Switzerland, 2014 Bifactor model nationallicence Dimensionality nationallicence Factor analyses nationallicence Vitality nationallicence Fatigue nationallicence Quality of life nationallicence Deng Nina Quantitative Health Sciences Department, University of Massachusetts Medical School, 01655, Worcester, MA, USA aut Guyer Rick John Ware Research Group, Incorporated, One Innovation Drive, Suite 400, 01605, Worcester, MA, USA aut Ware Jr. John Quantitative Health Sciences Department, University of Massachusetts Medical School, 01655, Worcester, MA, USA aut Quality of Life Research Springer International Publishing 24/1(2015-01-01), 81-93 0962-9343 24:1<81 2015 24 11136 https://doi.org/10.1007/s11136-014-0839-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11136-014-0839-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Deng Nina Quantitative Health Sciences Department, University of Massachusetts Medical School, 01655, Worcester, MA, USA aut NATIONALLICENCE 700 1- Guyer Rick John Ware Research Group, Incorporated, One Innovation Drive, Suite 400, 01605, Worcester, MA, USA aut NATIONALLICENCE 700 1- Ware Jr John Quantitative Health Sciences Department, University of Massachusetts Medical School, 01655, Worcester, MA, USA aut NATIONALLICENCE 773 0- Quality of Life Research Springer International Publishing 24/1(2015-01-01), 81-93 0962-9343 24:1<81 2015 24 11136