The single-most important factor determining your chances of survival during COVID is age.
There are co-morbidities and other differences such as access to health care which modify your prognosis, but no single factor is more important in determining survival rate than age (e.g., someone over 80 is more than 100 times more likely to die from COVID than someone under 30).
This allows for predictions between nations very different in age. In South Africa, almost 6% of the population is elderly (age 65 or over), but in Sweden, almost 21% of the population is elderly — more than 3 times the share of elderly who make up the population:
This means that, other things equal, if South Africa experiences a cumulative excess death of 4,700 per million during COVID, then Sweden would be expected to experience a cumulative excess of over (4,700 * 3 =) 14,100 per million.
But when you look at how the cumulative excess death per million in these two nations actually played out, Sweden’s excess death is not more than 3 times higher than South Africa’s — but just the opposite (more than 3 times lower):
If the most important factor is age, how is this possible?