OBJECTIVES: The PsAQoL is a measure of quality of life (QoL) specific to psoriatic arthritis (PsA) first published in 2003. Content of the measure was derived entirely from qualitative interviews conducted with UK PsA patients. New language versions have since been developed for several European countries, the US, Canada, Argentina and Brazil. Interest in the PsAQoL has increased lately due to the need to determine changes in QoL associated with new biological treatments. In recent years there has been a move towards conducting clinical trials in developing countries. This has increased interest in adapting patient-reported outcome measures developed in Europe and the United States for use in new regions of the World. An important question remains to be answered; can such measures provide valid assessment of QoL in these regions?
METHODS: New adaptations are currently being produced for Eastern Europe (4), the Middle East (2), Central and South America (2) and Asia (5). The measures are being translated (using the two panel methodology required for needs-based measures) and tested with local patients by means of cognitive debriefing interviews.
RESULTS: To date cognitive debriefing interviews have confirmed the adapted measures’ acceptability to patients who found it easy to understand and complete. The adaptations also have good internal consistency (alphas 0.85) and reproducibility (test-retest reliability coefficients: 0.85). The adaptations also exhibited construct validity by their ability to distinguish groups of PsA patients that varied by perceived disease severity and general health and by correlating as expected (moderately) with the Nottingham Health Profile.
CONCLUSIONS: It is intended to use Item Response Theory analyses to determine whether respondents in the developing countries answer the PsAQoL in the same way as those in Western countries. This will show whether the scales work validly in the developing countries.
