Objectives: The study was designed to adapt the Stanford Health Assessment Questionnaire (HAQ) and the Rheumatoid Arthritis Quality of Life Questionnaire (RAQoL) for use in Denmark.
Method: The instruments were translated into Danish and then field-tested with 10 RA patients for relevance, and face and content validity. Reliability and validity were assessed by administering the new measures and a comparator instrument (the Danish Nottingham Health Profile) to 80 RA patients on two occasions.
Results: Patients found both measures acceptable and easy to complete. They had good test-retest reliability (>0.90) and internal consistency and were both able to discriminate between groups with different levels of functional status and self-perceived severity. When compared with the NHP sections, both measures showed expected convergence and divergence.
Conclusion: Given the excellent psychometric properties of the Danish versions of the RAQoL and HAQ, both are recommended for inclusion in clinical trials and studies.