Physicians' and Patients' Preferences Over the Attributes of Biological Agents Used In the Treatment of Rheumatic Diseases In Spain: A Conjoint Analysis


      To define the importance values assigned to the attributes of biological agents (BA) by Spanish rheumatologists and patients with rheumatic diseases: rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PA).


      Observational, cross-sectional design based on conjoint analysis. RA, AS and PA patients diagnosed at least 2 years prior and currently or previously (≤1 year ago) receiving BA for a minimum of 1 year were consecutively recruited. Rheumatologists with at least 3 year experience on BAs participated. A literature review and 4 focus groups were undertaken to identify attributes and levels. Scenarios were selected using orthogonal design. Participants ranked 8 scenarios from 1 (most preferred) to 8 (least preferred). Relative importance (RI) of attributes was calculated. Multivariate regression analysis was performed for each attribute.


      488 patients [male=50.9%; mean (SD) age=50.6 (12.06) years; RA=33.8%, AS=32.4%, PA=33.8%; mean time from diagnosis=12.6 (8.2) years] and 136 rheumatologists [male=50.4%; mean age=46.4 (9.1) years; mean time of practice=16.7 (8.8) years] took part. Most important attributes selected by patients and physicians, respectively, were: ‘Pain relief and improvement of the functional capacity’ (RI=49.1% and 48.9%); ‘Risk of adverse events’ (RI=31.8% and 31.5%), ‘Administration method’ (RI=10.2% and 11.4%) and ‘Time to perceive the need for a new dose’ (RI=9.0% and 8.2%). The ideal BA, for patients and physicians, should allow pain relief and an improvement of the functional capacity, with a low risk of adverse events, a long time prior to perceiving the need for a new dose and self-administration at home, when possible.


      Although efficacy and safety are key for patients with rheumatic diseases and rheumatologists to make a choice over a BA, the need for a low frequency of administration and the administration method also play an important role as preference attributes for BAs in Spain.