Background The Animated Activity Questionnaire (AAQ) measures activity limitations in hip and knee osteoarthritis (HKOA), and demonstrated good validity and reliability . The AAQ shows stylized video animations of different levels of activity performance. Patients are asked to choose which video best matches their own performance. Accordingly, for international studies, the AAQ should show minimal Differential Item Functioning (DIF) across countries, which means that patients from different countries with the same level of activity limitations should have the same score on each item.
Objectives To evaluate cross-cultural validity of the AAQ.
Methods In 7 European countries patients were asked to complete the AAQ. An example of an item of the AAQ is shown on: http://kmin-vumc.nl/_14_0.html. Ordinal logistic regression was used to evaluate DIF across languages (Dutch versus 6 other languages). As a criterion for uniform DIF we used an odds ratio outside the interval 0.53–1.89. An significant interaction term (p-value <0.05) between translation item score and original Dutch score was considered as non-uniform DIF. Analyses were adjusted for sex, age, and affected joint.
Results Data available were from: Netherlands (N=279), Denmark (N=109), France (N=121), Italy (N=203), United Kingdom (N=142), Norway (N=62), and Spain (N=37). Compared to Dutch, none of the 17 items showed DIF in Danish and French; uniform DIF occurred in 1 item for Norwegian versus Dutch and English versus Dutch; for Spanish versus Dutch 1 item showed uniform DIF, and 1 item showed non-uniform DIF; for Italian versus Dutch 3 items showed uniform DIF, and 3 items showed non-uniform DIF.
Conclusions Cross-cultural validity of the AAQ looks promising. Further analyses with more data per country are needed and currently collected. Since minimal translation is needed for the AAQ, cross-cultural differences will mainly be based on cultural differences. The AAQ seems to have great potential for international use in research and daily clinical practice.
Peter WF et al. Development and preliminary testing of a computerized animated activity questionnaire in patients with hip and knee osteoarthritis. Arthritis Care Res (Hoboken). 2015 Jan;67(1):32-9.
Acknowledgements Funding: EULAR Patient Reported Outcome research grant.
Disclosure of Interest None declared