Included studies
| Author and year | Country (region) | Estimated latitude | Total MS (n) | Months associated with an excess risk of MS (OR; 95% CI) | Months associated with a lower risk of MS (OR; 95% CI) |
|---|---|---|---|---|---|
| Disanto, 201212 | UK | 53.1°N | 26 994 | April (1.05; 1.002–1.09) | October (0.96; 0.92 to 1.00) |
| May (1.08; 1.04–1.13) | November (0.96; 0.91 to 1.00) | ||||
| June (1.04; 1.01–1.09) | |||||
| Menni, 201211 | Italy (Milan, Pavia, Sardinia) | 45.2°N | 2737 | April (1.17; 1.02–1.32) | October (0.88; 0.76 to 0.99) |
| Denmark | 55.7°N | 15 900 | Nil | November (0.94; 0.89 to 1.00) | |
| USA, Caucasians | Excluded | 50 650 | June (1.06; 1.03 to 1.09) July (1.04; 1.01 to 1.07) | January (0.97; 0.94 to 1.00) February (0.97; 0.94 to 1.00) October (0.97; 0.94 to 1.00) | |
| USA, African Americans | Excluded | 5370 | July (1.11; 1.01 to 1.21) | Nil | |
| Givon, 201221 | Israel (Tel Hashomer) | 32.3°N | 2264 | Nil | December (0.84; 0.71 to 0.96) |
| Saastamoinen, 201110 | Finland (Helsinki) | 62.4°N | 8359 | April (1.09; 1.01 to 1.17) | January (0.91; 0.84 to 0.98) |
| November (0.89; 0.82 to 0.96) | |||||
| Bayes, 201017 | Scotland (Glasgow) | 56.8°N | 1309 | Spring (March, April, May) (1.17; 1.05 to 1.29) | Autumn (September, October, November) (0.87; 0.77 to 0.98) |
| Salzer, 201020 | Sweden (Umea) | 59.3°N | 9361 | June (1.11; 1.03 to 1.19) | January (0.90; 0.84 to 0.98) December (0.92; 0.85 to 1.00) |
| Ramagopalan, 200918 | Canada, Norway and Sweden | Excluded | 4834 | Nil | Nil |
| Sadovnick, 200719 | Canada | 56.8°N | 14 799 | June (0.95; 0.90 to 1.00) | November (0.90; 0.84 to 0.95) |
| Willer, 20059 | Canada | 56.8°N | 17 874 | Nil | November (0.91; 0.85 to 0.97) |
| UK | 53.1°N | 11 502 | May (1.18; 1.10 to 1.26) | November (0.89; 0.81 to 0.98) | |
| December (0.91; 0.83 to 0.99) | |||||
| Salemi, 200022 | Sicily | 37.6°N | 965 | Nil | Nil |
MS, multiple sclerosis.