Observed:expected MS cases by month of birth.
| Observed:expected MS births (ratio (95% CI); significance) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Analysis | January | February | March | April | May | June | July | August | September | October | November | December |
| All studies (n=151 978) | 0.96 (0.92 to 1.01) | 0.98 (0.94 to 1.01) | 0.99 (0.95 to 1.03) | 1.05 (1.00 to 1.11) p=0.05 | 1.05 (0.98 to 1.13) | 1.05 (0.93 to 1.19) | 1.03 (0.98 to 1.08) | 1.01 (0.98 to 1.05) | 0.98 (0.95 to 1.01) | 0.95 (0.91 to 1.00) p=0.04 | 0.92 (0.86 to 0.98) p=0.01 | 0.98 (0.96 to 1.01) |
| Population conservative (n=140 474) | 0.95 (0.91 to 1.00) p=0.07 | 0.98 (0.04 to 1.02) | 0.99 (0.95 to 1.04) | 1.05 (0.99 to 1.12) p=0.08 | 1.03 (0.98 to 1.09) | 1.05 (0.91 to 1.02) | 1.02 (0.97 to 1.08) | 1.01 (0.98 to 1.05) | 0.98 (0.95 to 1.02) | 0.96 (0.91 to 1.01) | 0.93 (0.87 to 1.00) p=0.04 | 0.98 (0.93 to 1.03) |
| Geographically conservative (n=89 059) | 0.95 (0.88 to 1.02) | 1.01 (0.96 to 1.06) | 0.99 (0.94 to 1.04) | 1.08 (1.03 to 1.12) p=0.001 | 1.11 (1.03 to 1.21) p=0.007 | 1.06 (1.00 to 1.13) p=0.05 | 1.01 (0.97 to 1.06) | 0.99 (0.94 to 1.04) | 0.96 (0.92 to 1.01) | 0.94 (0.89 to 0.98) p=0.006 | 0.89 (0.82 to 0.96) p=0.004 | 0.97 (0.90 to 1.04) |
| Overall conservative (n=78 488) | 0.93 (0.86 to 1.01) | 1.01 (0.96 to 1.06) | 0.99 (0.93 to 1.06) | 1.08 (1.02 to 1.13) p=0.004 | 1.09 (1.03 to 1.14) p=0.002 | 1.06 (0.99 to 1.14) | 1.00 (0.96 to 1.05) | 0.99 (0.94 to 1.05) | 0.97 (0.92 to 1.01) | 0.95 (0.90 to 1.00) p=0.03 | 0.90 (0.82 to 0.99) p=0.03 | 0.99 (0.93 to 1.06) |
p values are given for significant results in bold, and for borderline significant results (not bold).
MS, multiple sclerosis.