Characteristics for each cohort
| Cohort | ||||
|---|---|---|---|---|
| Leiden-EAC (n=600) | Groningen (n=275) | Sheffield (n=396) | Lund (n=147) | |
| Year of diagnosis | 1993–2006 | 1945–2001 | 1938–2003 | 1985–1989 |
| Follow-up years* | 7 years | 14 years | Not applicable* | 5 years |
| Total number of x-ray sets | 2846 | 862 | 396 | 781 |
| Method of scoring | SHS | SHS | Larsen | Larsen |
| Female, n (%) | 412 (69) | 194 (71) | 290 (73) | 98 (67) |
| Age at diagnosis (years), mean±SD | 56±16 | 49±13 | 46±13 | 51±12 |
| Anti-CCP+, n (%) | 323 (55) | 160 (80) | 302 (79) | 114 (80) |
↵* Data of Leiden-EAC, Groningen and Lund were collected from baseline onwards for 7, 14 and 5 years of follow-up, respectively. The data of Sheffield were collected once during the disease period; the mean disease duration was 15 years (range: 3–65 years).
EAC, Early Arthritis Clinic; SHS, Sharp van-der-Heijde score; anti-CCP, anti-citrillunated peptide antibodies