ObjectivesTo estimate the frequency of reporting composite indices evaluating axial spondyloarthritis (axSpA) disease activity in daily practice and to assess its impact on the secukinumab (SEC) retention rate.MethodsStudy design: Retrospective, multicentre. Data collected: (1) Recommended composite indices: Bath Ankylosing Spondyltitis Disease Activity Index (BASDAI) +C reactive protein or Ankylosing Spondylitis Disease Activity Score (ASDAS) at the time of initiation of SEC and at least once during the first year of follow-up; (2) Drug retention rate: percentage of patients still on SEC over time according to whether at least one recommended composite index had been optimally reported.ResultsA recommended composite index has been collected in 22% of the 906 enrolled axSpA patients. The percentage of patients still on treatment after 1, 2 and 3 years of follow-up was greater in those for whom at least one composite index had been optimally reported (respectively, 64% (57–71) vs 57% (54–61), 55% (48–62) vs 41% (38–45) and 52% (44–59) vs 38% (34–42), log rank test, p=0.016) with a lower risk of SEC discontinuation for these patients (HR: 0.70 (95% CI 0.5 to 0.88), Cox model, p=0.003).ConclusionThis study suggests that reporting of recommended composites indices for monitoring axSpA might be associated with higher retention rates of biological therapies.