Onset of RA cases and dates of vaccination against hepatitis B, tetanus, and influenza were identified in a retrospective chart review of approximately 1 million Kaiser Permanente Northern California members ages 15–59 years from 1997 through 1999. In a cohort analysis, rates of new-onset RA were compared between vaccinated and unvaccinated within 90, 180, and 365 days. In a case-control analysis, rates of vaccination during exposure intervals (90, 180, 365, and 730 days) were compared between cases and controls using conditional logistic regression.
378 RA cases were included in the cohort analysis; 37 additional cases were included in the case-control analysis. In the cohort analysis the relative risks of RA onset within 90, 180, or 365 days of hepatitis B vaccination were not significant (R.R. = 1.44, p = 0.53; R.R. = 1.67, p = 0.22; R.R. = 1.23, p = 0.59 respectively). We found a possible association between RA and influenza vaccine in the previous 180 and 365 days in the cohort analysis (R.R = 1.36, p = 0.03; R.R. = 1.34, p = 0.01 respectively), but in the case-control analysis, cases were no more likely than controls to have received any of the three vaccines.
In this large retrospective study we found no statistically significant association between exposure to hepatitis B vaccine and onset of RA. A possible association between RA and influenza vaccination in the cohort study was not borne out in the larger case-control analysis.