Relative incidence (and 95% confidence intervals) of a general practice consultation for possible gait disorder within 60 days of MMR vaccine in children aged 12 to <24 months according to number of doses of thiomersal containing vaccines given by 4 months of age (A) and mercury exposure intensity in the first six months of life (B)
| (A) Type of gait disorder (category) | Three doses by 4 months of age | RI (95% CI) [n] for 6–60 days | p value comparing No, Yes |
|---|---|---|---|
| All cases (A to F) | No | 0.99 (0.80 to 1.23) [117] | 0.27 |
| Yes | 0.82 (0.60 to 1.12) [52] | ||
| Unsteady gait (B) | No | 1.59 (0.70 to 3.63) [9] | 0.86 |
| Yes | 1.43 (0.51 to 4.02) [6] | ||
| Unsteady/ataxia (A and B) | No | 1.41 (0.68 to 2.93 [11] | 0.84 |
| Yes | 1.34 (0.53 to 3.41) [7] |
| (B) Type of gait disorder (category) | Mercury exposure intensity | RI (95% CI) [n] for 6–60 days | p value comparing quartiles |
|---|---|---|---|
| Number of cases in square brackets. | |||
| All cases (A to F) | Quartile 1 | 0.83 (0.56 to 1.22) [31] | 0.76 |
| Quartile 2 | 1.04 (0.76 to 1.42) [50] | ||
| Quartile 3 | 0.99 (0.72 to 1.36) [49] | ||
| Quartile 4 | 0.85 (0.60 to 1.21) [39] | ||
| Unsteady/ataxia (A and B) | Quartile 1 | 1.30 (0.35 to 4.79) [3] | 0.81 |
| Quartile 2 | 1.77 (0.71 to 4.42) [7] | ||
| Quartile 3 | 1.03 (0.28 to 3.80) [3] | ||
| Quartile 4 | 1.30 (0.45 to 3.81) [5] | ||