It looks like they compared data gathered from February of 2021 to data gathered in March of 2020; no data from 2022 was used for analysis - so yes, largely before populations were vaccinated. I don't know what the policy was exactly in the UK for vaccination and how vaccination for at-risk populations was handled, but I'm pretty sure like us they started vaccinating high-risk people in December or January of 20/21.
The study was also designed to gather information not just about the individual themselves:
Interestingly, we found that participants with vicarious health anxiety were not necessarily worried about their own health at all. One might speculate that the burden of the health of a vulnerable person you care about – in particular, the knowledge that inadvertently transmitting COVID to them can have grave consequences – is more emotionally challenging than taking responsibility for your own health.
Anecdotally (and personally), I am absolutely worried about giving Covid to my wife, daughter or elder parents; it drives my decision making.
You're right though because it's hard to get a bead on the actual risk in July of 2022 vs March of 2020 vs February of 2021. Some things are better, but now that there's immune escape, the potential for infection ( and complications) is back so comparing anxiety isn't a 1:1 thing - you'd really need to dial the questions in as part of the survey and that's not easy.
I hadn't see it regardless, so thanks for sharing.