Table 4

 Relative risk (RR) including 95% confidence intervals (CI) of malignant lymphoma in one prevalent cohort, one incident cohort, and one TNF antagonist treated cohort, respectively, of Swedish patients with RA

CovariatePerson-yearsLymphomas (n)Relative risk (95% CI)
RRs estimated using Poisson regression, adjusted for all parameters in table.
*Counting from date of first discharge with RA (Inpatient Register RA cohort) or specified date of onset of RA (Early Arthritis Register and TNF antagonist cohort).
RA cohort
Inpatient register cohort2971023191.0 (reference)
Cohort with early arthritis13292110.8 (0.4 to 1.4)
TNF antagonist cohort971591.1 (0.6 to 2.1)
Male825961382.0 (1.6 to 2.4)
Female2375132011.0 (reference)
Age at entry (years)
16–442770291.0 (reference)
45–741906311973.1 (1.6 to 6.1)
75+1017761334.1 (2.1 to 8.0)
Time with RA* (years)
0–41370531590.9 (0.6 to 1.1)
5–973708730.8 (0.7 to 1.1)
10+1089111071.0 (reference)