The relation between the occurrence of cold spells and the risk of SCD by various subgroups of cases over 34 years of age
| Subgroup | OR (95% CI) | Q-statistics (p) |
| Age | ||
| 35–64 | 1.28 (0.84 to 1.97) | 0.03 (0.84) |
| ≥65 | 1.36 (0.91 to 2.04) | |
| Sex | ||
| Male | 1.30 (0.94 to 1.81) | 0.04 (0.83) |
| Female | 1.41 (0.74 to 2.67) | |
| Autopsy finding | ||
| Ischaemic | 1.55 (1.12 to 2.13) | 3.85 (0.05) |
| Non-ischaemic | 0.68 (0.32 to 1.45) |
SCD, sudden cardiac death.