Evaluation of 2 screening strategies for early identification of patients with axial spondyloarthritis in primary care.

OBJECTIVE: To evaluate 2 referral strategies for axial spondyloarthritis (SpA) in patients with chronic low back pain at the primary care level.

METHODS: Referral physicians (n = 259) were randomly assigned to either Strategy 1 or Strategy 2 in order to refer patients with chronic back pain (duration > 3 months), age at onset of back pain < 45 years, and no diagnosis of axial SpA, to a cooperating rheumatologist (n = 43). According to Strategy 1, suitable patients were referred if at least 1 of the following screening criteria was present: inflammatory back pain, HLA-B27, or sacroiliitis detected by imaging. According to Strategy 2, patients were referred if 2 out of 5 criteria were positive: the same 3 criteria from Strategy 1 and additionally a positive family history of ankylosing spondylitis (AS) or a good treatment response to nonsteroidal antiinflammatory drugs. The final diagnosis of the rheumatologist was used as the "gold standard."

RESULTS: In total, 560 consecutively referred patients were included in the analysis. Among 318 patients referred by Strategy 1, 41.8% (95% CI 36.5%-47.3%) were diagnosed with definite axial SpA. Among 242 patients referred by the second strategy, definite axial SpA was diagnosed in 36.8% (95% CI 31.0%-43.0%) of the cases.

CONCLUSION: Both referral strategies demonstrated comparable performance in identification of patients with axial SpA. Strategy 1 might be preferred as an easy and reliable screening method for axial SpA at the primary care level.