Assessing internal construct validity of DAPSA and DAPSA28 in psoriatic arthritis: a European observational study using confirmatory factor analysis and additional psychometric testing
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023728%3A_____%2F25%3AN0000010" target="_blank" >RIV/00023728:_____/25:N0000010 - isvavai.cz</a>
Alternative codes found
RIV/00216208:11110/25:10507310
Result on the web
<a href="https://doi.org/10.1136/" target="_blank" >https://doi.org/10.1136/</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1136/rmdopen-2025-006104" target="_blank" >10.1136/rmdopen-2025-006104</a>
Alternative languages
Result language
angličtina
Original language name
Assessing internal construct validity of DAPSA and DAPSA28 in psoriatic arthritis: a European observational study using confirmatory factor analysis and additional psychometric testing
Original language description
The Disease Activity index for Psoriatic Arthritis (DAPSA) was developed to assess disease activity in patients with psoriatic arthritis (PsA). A modified version, DAPSA28, uses 28 joints instead of 66/68. This study evaluated key psychometric properties of DAPSA and DAPSA28. Data from 1865 patients with PsA in the European Spondyloarthritis (EuroSpA) Research Collaboration Network, having DAPSA and DAPSA28 scores at baseline and follow-up, were analysed. Tests included assessment of internal construct validity by scree plots, confirmatory factor analysis (CFA) and structural equation modelling (SEM), supplemented by tests of differential item functioning (DIF) and evaluation of internal consistency reliability by Cronbach's α (CA). A subset of 625 patients was used for most analyses, except descriptive statistics, correlation matrix and CA. One-dimensional CFA models for DAPSA and DAPSA28 showed acceptable model fit at baseline (root mean square error of approximation, RMSEA: 0.020, 0.034). However, model fit at 6 months follow-up was poor (RMSEA: 0.057, 0.063). SEM combining baseline and follow-up data could not identify an acceptable model fit. DIF was found for sex and country. CA indicated acceptable internal consistency (DAPSA: 0.65; DAPSA28: 0.63). Heterogeneity across countries was observed. Overall, the model fit was acceptable across model fit statistics, supporting internal construct validity, but some evidence of misfit at country level was disclosed. Our findings support acceptable internal consistency reliability, but DIF was found for sex and country. Based on mixed results of model fit and DIF, further investigation of these and other PsA disease activity measures is warranted.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
30226 - Rheumatology
Result continuities
Project
—
Continuities
V - Vyzkumna aktivita podporovana z jinych verejnych zdroju
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
RMD OPEN
ISSN
2056-5933
e-ISSN
2056-5933
Volume of the periodical
11
Issue of the periodical within the volume
Art.Nr. e006104
Country of publishing house
GB - UNITED KINGDOM
Number of pages
10
Pages from-to
1-10
UT code for WoS article
001649175400001
EID of the result in the Scopus database
2-s2.0-105025731576