Referral Strategy for Axial Spondyloarthritis : Development, validation and impact in a chronic low back pain population

The studies described in this thesis cover the findings of the CAse Finding Axial SPondyloArthritis (CaFaSpA) studies. Axial spondyloarthritis (axSpA) is a chronic, inflammatory disease affecting the axial skeleton and it is characterized by chronic low back pain (CLBP) and stiffness of the axial skeleton. At this moment there is an average diagnostic delay of 8.5 years between the start of the symptoms and the diagnosis axSpA. A missed opportunity as effective treatment for axSpA is available. The aim of the CaFaSpA studies was to establish the prevalence of axSpA within a young CLBP population and to develop and validate a referral strategy for axSpA which can be used by primary care physicians. A validated referral strategy for axSpA can be used to achieve the goal of early recognition and referral of axSpA patients to rheumatologists.
The thesis is divided in four parts; at first the prevalence of axSpA within a young CLBP population is established, the second part describes the development of a referral strategy for axSpA, the third part covers the external validation of referral strategies for axSpA and the fourth part evaluates the impact of axSpA on work participation and the impact of a referral strategy for axSpA on young patients with CLBP and whether this referral strategy will be cost-effective.