Is Group or Initial Population required

Within the Measure profile, all that's being said is that each group must have at least one population element. The Measure profile serves as a base profile for each of the more-specific scoring profiles: Cohort, Proportion, Ratio, and Continuous-variable. Each of the more specific scoring profiles specify slices for the population elements of the group that are appropriate for that scoring type. However, it is also the intent that each of the more specific scoring profiles should ensure that there is at least one group. Update group cardinality to 1..* for each of Cohort, Proportion, Ratio, and Continuous-Variable profiles (Note this does not apply to composites, which would only use a group if they were defining components of the composite as part of the same measure instance).