An investigator wants to design a study that entails multiple variables and two population groups.

First population: inmates in custody

Second population: correctional officers

The investigator wants to determine the stress levels of both inmates and staff members prior to COVID, after COVID, AND after either a staff or inmate in their specific facility tested positive for COVID. I would like to include two different institutions ( one institution where no one has tested positive and one institution where many have tested positive)

How would one go about setting up this experimental design, test it and which diagnostic tool would one use to test for variance?