HR and 95% CI for death comparing patients with RF-positive and RF-negative patients with RA compared with the general population, adjusted for sex, residential area, year of diagnosis and age. Overall and stratified by calendar period of RA diagnosis and time since RA diagnosis
| Calendar period of RA diagnosis | HR (95% CI) RA duration categories | |||
| <1 year | 1 to <5 years | 5–10 years | >10 years | |
| Total study period | ||||
| RF negative | 0.43 (0.32 to 0.57) | 0.63 (0.55 to 0.72) | 0.82 (0.71 to 0.93) | 1.24 (1.04 to 1.48) |
| RF positive | 0.68 (0.55 to 0.84) | 1.11 (1.01 to 1.22) | 1.34 (1.21 to 1.48) | 1.55 (1.35 to 1.77) |
| 1997–2001 | ||||
| RF negative | 0.37 (0.17 to 0.80) | 0.54 (0.40 to 0.74) | 0.81 (0.65 to 1.01) | 1.16 (0.94 to 1.43) |
| RF positive | 0.72 (0.45 to 1.15) | 1.01 (0.82 to 1.25) | 1.27 (1.07 to 1.51) | 1.57 (1.35 to 1.83) |
| 2002–2006 | ||||
| RF negative | 0.46 (0.25 to 0.86) | 0.68 (0.53 to 0.87) | 0.87 (0.71 to 1.06) | 1.49 (1.07 to 2.07) |
| RF positive | 0.32 (0.18 to 0.57) | 1.01 (0.85 to 1.20) | 1.37 (1.19 to 1.58) | 1.46 (1.12 to 1.91) |
| 2007–2011 | ||||
| RF negative | 0.43 (0.27 to 0.71) | 0.65 (0.52 to 0.81) | 0.72 (0.52 to 0.99) | – |
| RF positive | 0.86 (0.61 to 1.22) | 1.27 (1.09 to 1.47) | 1.40 (1.11 to 1.75) | – |
| 2012–2015 | ||||
| RF negative | 0.42 (0.24 to 0.74) | 0.61 (0.39 to 0.95) | – | – |
| RF positive | 0.83 (0.55 to 1.24) | 1.08 (0.79 to 1.49) | – | – |
RA, rheumatoid arthritis; RF, rheumatoid factor.