If I understood everything correctly, I can add this as a custom prescreening option and will get the individuals’ answers to the respective screening question in my Prolific export, right?
Yes. But remind that there are always two ways to use the prescreeners:
to get information on some key feature of participants at the end of the study (information that you get extracting the final data). In this case, in the custom prescreening you need to select all possible responses:
in order to get a sample of participants filtered by some characteristic, and imo this better suits your case. For example, I would only go for those whose response is “more than once a week”, “about once a week”, “several times a month” or “about once a month”.
I was now wondering how recent the answers to the screening questions are, as the shopping preferences might have changed in the course of the pandemic.
As you may already know, these are answers that participants provide at the time of subscription to Prolific. However, good news is that Prolific routinely asks for updates on these questions (and if you want to give suggestions on how to improve this mechanism, you can join us here!)
Also, it’s not possible to get exact dates for individual participants responses. However, I think that @Josh can be able to give you the intervals at which this specific “screener” must be updated. So I’d suggest to wait for his final word on this!