Background The ASAS Health Index (ASAS HI) is a disease-specific questionnaire aiming at measurement of health in patients with spondyloarthritis (SpA) which has been developed by Assessment of SpondyloArthritis international Society (ASAS). The 17 items of the ASAS HI address aspects of pain, emotional functions, sleep, sexual functions, mobility, self-care and community life based on the International Classification of Functioning, Disability and Health (ICF). These items can serve as the starting point to develop a disease-specific utility instrument that will enable to calculate disease specific quality adjusted life-years. To construct such utility instrument, the development steps require that the number of items should be reduced to a more manageable number of items. This selection should be based on items, which are most essential to patient's health and on items which are most preferred by patients. It is not know which aspects of health matter most to patients with SpA and also the knowledge about patient's preferences is limited.

Objectives To understand the relative importance of the different items of the ASAS HI for functioning and health of patients with SpA.

Methods A best-worse experiment was conducted using a questionnaire in patients with SpA from 20 countries worldwide. Patients answered 17 choice tasks that were constructed using the Sawtooth software. In each task, patients were asked to choose the most important item and the least important from a set of four items about their functioning and health. The estimated hierarchical Bayes method was used to generate the mean relative importance score for each item.

Results 206 patients (59.7% male, mean (SD) age 42.4 (13.9) years, mean (SD) BASDAI 3.8 (2.3)) with SpA completed the experiment. The five most important items are pain, sleep, standing, exhausting, and motivation to do anything that requires physical effort (table 1). Eight items address concepts which are less important for the patients: toileting, sexual relations, driving, contact with people, walking outdoors, concentration, washing hair, and be able to overcome difficulties. Four items addresses concepts, which showed intermediate results addressing concepts of running, frustration, traveling, and financial changes. Subgroup analysis regarding subgroups of SpA and European versus Non-European countries showed robust results among subgroups.

Conclusions This study provides information on the relative importance for patients with SpA of the items of the ASAS HI that will be used for the development of a utility value for patienst with SpA.

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.2883