Table 1

 Relative risk of developing rheumatoid factor (RF) positive rheumatoid arthritis, RF negative rheumatoid arthritis, and rheumatoid arthritis overall for subjects without a university degree compared with those with a university degree, by sex

Ca/CoRR*95% CIRR**95% CI
RF+ RANo university degree340/5841.51.1 to to 2.2
University degree†82/2041.01.0
RF− RANo university degree170/5840.90.7 to to 1.3
University degree†61/2041.01.0
Total RANo university degree510/5841.31.0 to to 1.7
University degree†143/2041.01.0
Ca/CoRR*95% CIRR**95% CI
RF+ RANo university degree162/2602.11.3 to to 3.6
University degree†22/751.01.0
RF to RANo university degree80/2602.31.1 to to 5.5
University degree†12/751.01.0
Total RANo university degree242/2602.21.4 to to 3.6
University degree†34/751.01.0to
Ca/CoRR§95% CIRR§§95% CI
Values are relative risks with 95% confidence intervals.
*Relative risk adjusted for age and residential area.
**Relative risk adjusted for age, residential area, and smoking.
§Relative risk adjusted for age, residential area, and sex.
§§Relative risk adjusted for age, residential area, sex, and smoking.
†Reference group.
Ca/Co, number of exposed cases/number of exposed controls; CI, confidence interval; RF, rheumatoid factor; RR, relative risk.
RF+ RANo university degree502/8441.61.3 to to 2.2
University degree†104/2791.01.0
RF− RANo university degree250/8441.20.8 to to 1.6
University degree†73/2791.01.0
Total RANo university degree752/8441.41.2 to to 1.9
University degree†177/2791.01.0