Table 1.
Characteristics of the eight included studies.
| Name cohort or author | nr-axSpA n | AS n | Study design | Year of inclusion | Data collection | Maximum disease duration for inclusion, years | Mean symptom duration nr-axSpA, mean years (SD) | Mean symptom duration AS, mean years (SD) |
|---|---|---|---|---|---|---|---|---|
| GESPIC | 226 | 236 | Cohort | 2000–2004 | Baseline | AS: <10; nr-axSpA <5 | 2.6 (1.7) | 5.2 (2.3) |
| Kiltz | 44 | 56 | Cross-sectional | Unknown | n.a. | No | 9.4 (9.5) | 12.8 (10.7) |
| DESIR | 295 | 180 | Cohort | 2007–2010 | Baseline | <3 | 1.5 (0.9) | 1.6 (0.9) |
| SCQM | 232 | 838 | Cohort | 2005–2011 | Baseline | No | 5.5 (1.8–13.7)b | 12.7 (6.4–22.7)b |
| SPACE | 58 | 23 | Cohort | 2009–2014 | Baseline | <2 | 1.1 (0.6) | 1.3 (0.7) |
| Esperanza | 182 | 109 | Cohort | 2008–2011 | Baseline | <2 | 1.0 (1.6) | 1.2 (0.5) |
| Wallis | 73 | 639 | Cohort | 2003–2012 | Baseline | No | 12.1 (8.5)a | 17.7 (12.3)a |
| ESPAC | 132 | 155 | Cohort | 2009–2014 | Unknown | No | 5.8 (5.5) | 11.7 (7.7) |
aMean disease duration. bMedian (interquartile range). Nr-axSpA non-radiographic axial spondyloarthritis, AS ankylosing spondylitis, SD standard deviation, GESPIC GErman SPondyloarthritis Inception Cohort, n.a. not applicable, DESIR Devenir des Spondylarthropathies Indifferenciées Récentes, SCQM Swiss Clinical Quality Management, SPACE SPondyloArthritis Caught Early, ESPAC Erciyes SPondyloArthritis