prior observation for matched cohort will be the same as sample for matchCohorts()

[daniellenewby]

I have a cancer cohort with patients with a diagnosis of cancer with at least 365 days of prior history. I want to match these people using the matchCohorts(). However, will the matched cohort of "controls" without cancer also have 365 days of prior observation? From the function i do not think this is the case. If not then there could be the potential for sample cohort (people with cancer) to be matched to the matched cohort (people without cancer) who have less than 365 days of observation. Therefore when comparing characteristics between the matched and sample might introduce a little bias? It might not make too much difference as it is supposed to be random matching but i think it needs discussion on if this should be included the prior history from the sample or somehow can be detected from the sample cohort and applied to the matched cohort. Thanks!

[nmercadeb]

Maybe we can add a subsetCohort argument to pick controls only from that cohort, using its entry and exit dates?
This way, if some inlcusion/exclusion criteria was applied to the target cohort, the user could apply it to a population cohort that would then be used to find controls