In my example at https://gist.github.com/jmandel/41f47088085cf4633506b43438925389#file-tracking-examples-saner-json-L45, you can kind of see in the Group.name that we're building up a facet structure: the group is called "Active, Unoccupied, Non-isolating ICU Beds in Hospital A Ward 1". But if you wanted to report on different aspects (e.g., swap Occupied-> Closed, or Non-isolating->ICU, or ICU->Acute, or any other combination), then you need to create a combinatorial number of groups to express this. Whereas MeasureReport supports built-in faceting, so you can say all this stuff (summary, and breakdowns by characteristic or combination of characteristics) in a single place.
In my example at https://gist.github.com/jmandel/41f47088085cf4633506b43438925389#file-tracking-examples-saner-json-L45, you can kind of see in the
Group.name
that we're building up a facet structure: the group is called "Active, Unoccupied, Non-isolating ICU Beds in Hospital A Ward 1". But if you wanted to report on different aspects (e.g., swap Occupied-> Closed, or Non-isolating->ICU, or ICU->Acute, or any other combination), then you need to create a combinatorial number of groups to express this. Whereas MeasureReport supports built-in faceting, so you can say all this stuff (summary, and breakdowns by characteristic or combination of characteristics) in a single place.