title: Disease activity trajectories in early axial spondyloarthritis: results from the DESIR cohort.
abstract: BACKGROUND
  Disease activity may change over time in axial spondyloarthritis (axSpA). The objectives were to identify patterns of disease activity evolution in patients with early axSpA.
  
  
  METHODS
  Patients from the prospective early axSpA cohort (DEvenir des Spondyloarthrites Indifférenciées Récentes (DESIR)) who fulfilled the Assessment in SpondyloArthritis Society (ASAS) criteria for axSpA at baseline and with at least three Ankylosing Spondylitis Disease Activity Score (ASDAS) values available over the 3 years of follow-up were analysed.Statistical analyses:trajectories were estimated by group-based trajectory modelling; predisposing baseline factors for such trajectories were identified by univariate and multivariable multinomial (logit) regression; work disability over time was compared between the trajectories by Cox hazard model.
  
  
  RESULTS
  In all, 370 patients were analysed: mean disease duration was 1.6 (±0.9) years. The five distinct trajectories of disease activity over the 3 years were (t1) 'persistent moderate disease activity' (n=134 (36.2%)); (t2) 'persistent inactive disease' (n=66 (17.8%); (t3) 'changing from very high disease activity to inactive disease' ((n=29 (7.8%)); (t4) 'persistent high disease activity' (n=126 (34.1%)) and (t5) 'persistent very high disease activity' (n=15 (4.1%)). After adjustment for other characteristics, t2 was associated with a white-collar job (OR=2.6 (95% CI 1.0 to 6.7)) and t3 with male gender (OR=7.1 (1.6 to 32.2)), higher education level (OR=9.4 (1.4 to 63.4)) and peripheral joint involvement (OR=6.2 (1.23 to 31.32)). Patients from (t4) and (t5) were more often declared work disabled over follow-up (HR=5.2 (1.5 to 18.0) and HR=8.0 (1.3 to 47.9), respectively).
  
  
  CONCLUSIONS
  Trajectory modelling of disease activity was feasible in early axSpA: more than 30% patients (141/370) were in a trajectory with a persistent high disease activity. Persistent high disease activity trajectories were significantly associated with consequences on work.
  
  
  BACKGROUND
  NCT01648907.
authors.affiliation: Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Universités, UPMC Univ Paris 06, GRC-08, Paris, France.|Rheumatology Department, Paris Descartes University, Cochin Hospital, AP-HP, Paris, France.|Clinical Epidemiology and Biostatistics, PRES Sorbonne Paris-Cité, INSERM (U1153), Paris, France.
authors.forename: Anna
authors.identifier: http://orcid.org/0000-0003-2246-1986
authors.initials: A
authors.lastname: Molto
authors.affiliation: Department of Biostatistics Public Health and Medical Informatics, UPMC Université Paris 06, AP-HP, Pitié Salpêtrière Hospital, Paris, France.|Sorbonne University, Université Pierre et Marie Curie (UPMC) Univ Paris 6, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Tezenas du Montcel
authors.affiliation: Rheumatology Department, CHRU de Besançon, Université de Franche-Comté, Besançon, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wendling
authors.affiliation: Rheumatology Department, Paris Descartes University, Cochin Hospital, AP-HP, Paris, France.|Clinical Epidemiology and Biostatistics, PRES Sorbonne Paris-Cité, INSERM (U1153), Paris, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Dougados
authors.affiliation: Department of Biostatistics Public Health and Medical Informatics, UPMC Université Paris 06, AP-HP, Pitié Salpêtrière Hospital, Paris, France.|EA 4275 SPHERE, University of Nantes, Nantes, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Vanier
authors.affiliation: Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Universités, UPMC Univ Paris 06, GRC-08, Paris, France.|Department of Rheumatology, AP-HP, Pitié Salpêtrière Hospital, Paris, France.
authors.forename: Laure
authors.identifier: http://orcid.org/0000-0002-4528-310X
authors.initials: L
authors.lastname: Gossec
mesh_terms: D000328:Adult; D004522:Educational Status; D006801:Humans; D008137:Longitudinal Studies; D015233:Models, Statistical; D015999:Multivariate Analysis; D009790:Occupations; D011379:Prognosis; D011446:Prospective Studies; D012446:Sacroiliac Joint; D012720:Severity of Illness Index; D012737:Sex Factors; D025242:Spondylarthropathies / Q000188:drug therapy*; D063189:Symptom Assessment; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors; D014938:Work Capacity Evaluation; D055815:Young Adult
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: Disease Activity; Epidemiology; Outcomes research; Spondyloarthritis