TY - JOUR
T1 - Application of the health assessment questionnaire disability index to various rheumatic diseases
AU - van Groen, Maaike M.
AU - ten Klooster, Peter M.
AU - Taal, Erik
AU - van de Laar, Mart A.F.J.
AU - Glas, Cees A.W.
PY - 2010
Y1 - 2010
N2 - Purpose
To investigate whether the Stanford Health Assessment Questionnaire Disability Index (HAQ-DI) can serve as a generic instrument for measuring disability across different rheumatic diseases and to propose a scoring method based on item response theory (IRT) modeling to support this goal.
Methods
The HAQ-DI was administered to a cross-sectional sample of patients with confirmed rheumatoid arthritis (n = 619), osteoarthritis (n = 125), or gout (n = 102). The results were analyzed using the generalized partial credit model as an IRT model.
Results
It was found that 4 out of 8 item categories of the HAQ-DI displayed substantial differential item functioning (DIF) over the three diseases. Further, it was shown that this DIF could be modeled using an IRT model with disease-specific item parameters, which produces measures that are comparable for the three diseases.
Conclusion
Although the HAQ-DI partially functioned differently in the three disease groups, the measurement regarding the disability level of the patients can be made comparable using IRT methods
AB - Purpose
To investigate whether the Stanford Health Assessment Questionnaire Disability Index (HAQ-DI) can serve as a generic instrument for measuring disability across different rheumatic diseases and to propose a scoring method based on item response theory (IRT) modeling to support this goal.
Methods
The HAQ-DI was administered to a cross-sectional sample of patients with confirmed rheumatoid arthritis (n = 619), osteoarthritis (n = 125), or gout (n = 102). The results were analyzed using the generalized partial credit model as an IRT model.
Results
It was found that 4 out of 8 item categories of the HAQ-DI displayed substantial differential item functioning (DIF) over the three diseases. Further, it was shown that this DIF could be modeled using an IRT model with disease-specific item parameters, which produces measures that are comparable for the three diseases.
Conclusion
Although the HAQ-DI partially functioned differently in the three disease groups, the measurement regarding the disability level of the patients can be made comparable using IRT methods
U2 - 10.1007/s11136-010-9690-9
DO - 10.1007/s11136-010-9690-9
M3 - Article
VL - 19
SP - 1255
EP - 1263
JO - Quality of life research
JF - Quality of life research
SN - 0962-9343
IS - 9
ER -