TY - JOUR
T1 - Usefulness of EQ-5D for evaluation of health-related quality of life in young adults with first-episode psychosis
AU - Stochl, J.
AU - Croudace, T.
AU - Perez, J.
AU - Birchwood, M.
AU - Lester, H.
AU - Marshall, M.
AU - Amos, T.
AU - Sharma, V.
AU - Fowler, D.
AU - Jones, P. B.
AU - The National Eden Study Team
N1 - M1 - Article
PY - 2013/6
Y1 - 2013/6
N2 - PURPOSE: To evaluate the psychometric properties of the EQ-5D and the usefulness of this instrument in psychiatric practice as a measure of health-related quality of life (HRQoL) in a sample of young adults with first-episode psychosis. METHODS: The validity of individual questionnaire items is studied using an Item Response/Latent Trait Theory modeling approach. Sensitivity of response patterns on EQ-5D items to particular diagnostic subtypes of psychosis is investigated using a finite mixture modeling approach through latent class analysis. Finally, a structural equation modeling framework is used to study differential item functioning via a multigroup approach. RESULTS: Results suggest that the data closely correspond to the Rasch Rating Scale Model, and therefore that EQ-5D latent scores are equal interval measures. Despite comprising relatively few items, the instrument yields reliable measures of HRQoL for group comparisons and cost-effectiveness evaluation, but EQ-5D score is too imprecise for the assessment of HRQoL for clinical purposes at the individual level. A significant relationship was found between EQ-5D responses and type of psychosis due to inclusion of item anxiety/depression in EQ-5D. Two items (anxiety/depression, functioning in usual activities) showed an ethnicity bias. CONCLUSIONS: Psychometric evidence confirmed the EQ-5D to be a valid, interval measure that is scalable according to Rasch principles.
AB - PURPOSE: To evaluate the psychometric properties of the EQ-5D and the usefulness of this instrument in psychiatric practice as a measure of health-related quality of life (HRQoL) in a sample of young adults with first-episode psychosis. METHODS: The validity of individual questionnaire items is studied using an Item Response/Latent Trait Theory modeling approach. Sensitivity of response patterns on EQ-5D items to particular diagnostic subtypes of psychosis is investigated using a finite mixture modeling approach through latent class analysis. Finally, a structural equation modeling framework is used to study differential item functioning via a multigroup approach. RESULTS: Results suggest that the data closely correspond to the Rasch Rating Scale Model, and therefore that EQ-5D latent scores are equal interval measures. Despite comprising relatively few items, the instrument yields reliable measures of HRQoL for group comparisons and cost-effectiveness evaluation, but EQ-5D score is too imprecise for the assessment of HRQoL for clinical purposes at the individual level. A significant relationship was found between EQ-5D responses and type of psychosis due to inclusion of item anxiety/depression in EQ-5D. Two items (anxiety/depression, functioning in usual activities) showed an ethnicity bias. CONCLUSIONS: Psychometric evidence confirmed the EQ-5D to be a valid, interval measure that is scalable according to Rasch principles.
KW - Public Health, Environmental and Occupational Health
U2 - 10.1007/s11136-012-0222-7
DO - 10.1007/s11136-012-0222-7
M3 - Article
C2 - 22706728
SN - 1573-2649
VL - 22
SP - 1055
EP - 1063
JO - Quality of Life Research
JF - Quality of Life Research
IS - 5
ER -
