[tert101za]

I would advise reading the original paper as posted by several users: https://www.bmj.com/content/377/bmj-2021-069308

As I see it:

A) The paper is primarily a study of numerical trends.

B) Some potential policy causes for this difference are listed in the discussion section. While this is not the primary focus of this paper, the discussion links to several other prior studies regarding particular policies and their impacts.

C) However, more specific details (other than the above postulates) is not part of the paper's focus. This is acknowledged as a limitation in the study, and it is also acknowledged that other factors aside from policy (such as poor health or social and economic factors that may also motivate political preference) explain some of the hap. So it is important not to read too much detail into the cause of this gap at this time.