AB0915 ASSOCIATION BETWEEN DIAGNOSTIC DELAY AND ECONOMIC BURDEN RELATED TO AXIAL SPONDYLOARTHRITIS IN SPANISH POPULATION
Authors: M. Arévalo, L. Berbel-Arcobé, M. Aparicio, J. Calvet, A. Nack, X. Juanola, E. Toniolo, S. Maratia, E. Viciano, J. Gratacós
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Diagnostic delay of axial spondyloarthritis (axSpA) has been reported worldwide. In Spain, the mean time from symptoms onset to diagnosis is estimated at 8.5 years, being longer in women than men. Diagnostic delay can lead to greater functional impairment, higher direct and indirect costs and worse quality of life. Nevertheless, a more comprehensive assessment of the impact of delayed diagnosis on the disease evolution and the economic burden is needed. <h3>Objectives:</h3> To determine the association between the diagnostic delay of axSpA and healthcare resource use HRU (direct costs) and the loss of work productivity (indirect costs) in the 3 years after diagnosis. <h3>Methods:</h3> A retrospective observational study was conducted in 3 Spanish hospitals based on electronic medical records of patients with axSpA diagnosis in 2014-2016, with routine follow-up for 3 years. Sociodemographic (age at diagnosis, sex), clinical (date of symptom onset and diagnosis, type of axSpA [radiographic, non-radiographic], HLA-B27 status, BASDAI, ASDAS, CRP), HRU (visits to primary care, specialists, emergency department, hospitalisations and length of stay, laboratory and imaging tests, comorbidity and axSpA-related treatments), and incapacity for work were collected during 3 years following the diagnosis. The diagnostic delay was determined by calculating the time interval between the onset of symptoms and the date of formal diagnosis. Direct costs were calculated by multiplying the number of HRU by unit costs identified from official local sources. Indirect costs were calculated by multiplying the number of days with temporary or permanent incapacity to work by the cost of one working day according to the Spanish labour cost per worker. Mean total costs (direct and indirect) were calculated over the 3 years of follow-up. All costs were reported in € (2023). costs was estimated (Spearman's correlation coefficient), and the total 3-year costs was compared between patients with a longer delay and those with a shorter delay following a methodological approach based on median time as a cut-off value. The correlation between the time of diagnosis delay and total <h3>Results:</h3> We included 82 patients: 62.2% male; mean (standard deviation [SD]) age at diagnosis of 39.3 (11.7) years; 67.1% were diagnosed with radiographic axSpA, and 84.2% were HLA-B27 positive. At diagnosis and 3 years after diagnosis, the mean (SD) score for BASDAI was 4.0 (2.4) and 3.4 (2.2), ASDAS 2.8 (1.3) and 2.3 (1.1), and CRP 14.0 (28.9) and 4.5 (5.5) mg/L, respectively. The mean (SD) diagnostic delay was 10.1 (9.3) years, with a median (IQR) of 5.4 years (2.3-17.2). The mean total costs per patient accumulated over the 3 years of follow-up was €25,812.6, being €16,384.7 for direct costs and €9,427.9 for indirect costs. Although a low positive correlation was observed between the diagnostic delay and the total costs after the diagnosis, it did not reach statistical significance (Spearman's coefficient= 0.195; p-value= 0.080). Patients with a longer diagnostic delay (&gt;5.4 years) showed higher values for BASDAI, ASDAS and CRP at diagnosis than those with a shorter delay (≤5.4 years), with a statistically significant difference for BASDAI (mean [SD] 4.7 [2.4] vs 3.4 [2.3]). Moreover, patients with a longer diagnostic delay (&gt;5.4 years) had 57.1% higher total costs than those with a shorter delay (mean [SD] €31,717.7 [38,419.0] vs €20,188.7 [27,621.3, p-value of 0.029), and higher numbers of direct and indirect costs (mean [SD] €19,249.0 [18,473.3] vs €13,656.7 [13,656.8] and €12,468.6 [28,445.9] vs €6,532.0 [23,296.5], respectively). <h3>Conclusion:</h3> This study population shows a high diagnostic delay in axSpA in line with previous evidence. Moreover, patients with a diagnostic delay &gt;5.4 years (similar cut-off value to those recently published) had statistically significant higher disease activity at diagnosis and higher total costs (57%) for 3 years after diagnosis than those with a shorter delay. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> Funded by UCB Pharma. Medical writing provided by Outcomes10 and funded by UCB Pharma. <h3>Disclosure of Interests:</h3> Marta Arévalo: None declared, Laura Berbel-Arcobé Speakers bureau for Novartis, Lilly, AbbVie, Janssen, Theramex and MSD, Maria Aparicio: None declared, Joan Calvet Paid instructor for Novartis, UCB, Pfizer, AstraZeneca, Boerhinger, Galapagos, AbbVie, GSK, Speakers bureau for Pfizer, AbbVie, Novartis, MSD, UCB, Roche, Lilly, Galapagos, GSK, Grünenthal, Bioiberica, Astra Zeneca, Boehringer, Gilead, Sanofi, Grant/research support from Galapagos, AbbVie, Pfizer, Annika Nack: None declared, Xavier Juanola Speakers bureau for AbbVie and Lilly, Consultant for AbbVie, Lilly, Pfizer and UCB Pharma, Elide Toniolo Employee of UCB Pharma, Stefano Maratia Employee of UCB Pharma, Elena Viciano Employed by Outcomes 10, an independent research entity that has received fees from UCB for coordinating this research, Jordi Gratacós Speakers bureau for AbbVie, Janssen, UCB, Pfizer, Novartis, Lilly, BMS, MSK, Consultant for AbbVie, Janssen, UCB, Pfizer, Novartis, Lilly, BMS, MSK, Grant/research support from Pfizer, Galapagos.