Axial Spondyloarthritis in Primary care patients with chronic low back pain; a cross-sectional stratified validation study

*Chronic low back pain:
CAse-Finding Axial SPondyloArthropathy in general practice* (CAFASPA-II)

Recent years have seen a substantial improvement in the prognosis of patients
with axial spondyloarthropathy (SpA) due to the advent of new drugs and the
intensive use of existing drugs. It is important to ensure that the right
medication is instituted early in the disease process. The stumbling block as
far as early recognition is concerned is the absence of specific factors on
which to base the diagnosis. Furthermore, there is a seven-year delay before
abnormalities pathognomonic of sacroiliitis are visible on a conventional
x-ray. Predictive models have recently been developed for early recognition of
SpA, but these are based on patients who had already been referred to secondary
care and closer analysis shows that these patients had also already suffered
from inflammatory back pain for 7.7 years. Therefore, future research should
focus on early detection of SpA.

The identification of axial SpA in the primary-care setting and the
introduction of questionnaires that could optimize the pattern of referral to
secondary care is one of the most important objectives of the CAFASPA-II study.

This is a cross-sectional observational validation trial which will be
performed in close cooperation with GPs.

Prior to inclusion in the study, potential subjects are screened successively
by a GP, research assistant and investigator. Patients who exhibit features of
chronic low back pain will be examined for the presence of axial Spa and, if
necessary, treated in accordance with the guidelines. For patients with chronic
low back pain, in addition to completing questionnaires, the trial consists of
blood testing, x-ray examination and magnetic resonance imaging (MRI) of
sacroiliac (SI) joints. General practice groups will be invited to take part in
the study. It is expected that around 800 patients will be recruited in this
period. This number is considered sufficient to answer the questions that the
trial seeks to address.

Patients will be fully informed about the aim of the study and also about the
circumstances of the individual examination, the amount of time required and
the potential risks. The burden for the patient consists of the time spent
(questionnaires, physical examination), the provision of 32 ml of blood and the
need to undergo an x-ray and MRI of the SI joints.