Add in the attrition records drop when creating concept cohort

[nmercadeb]

- conceptCohort attrition:

>  attrition(cohort)
# A tibble: 4 × 7
  cohort_definition_id number_records number_subjects reason_id reason                       excluded_records excluded_subjects
                 <int>          <int>           <int>     <int> <chr>                                   <int>             <int>
1                    1              9               2         1 Initial qualifying events                   0                 0
2                    1              9               2         2 Record start <= record end                  0                 0
3                    1              9               2         3 Record in observation                       0                 0
4                    1              4               2         4 Collapse overlapping records                5                 0

- measurementCohort attrition( (after PR revision):

> cdm$cohort |> attrition()
# A tibble: 5 × 7
  cohort_definition_id number_records number_subjects reason_id reason                                    excluded_records excluded_subjects
                 <int>          <int>           <int>     <int> <chr>                                                <int>             <int>
1                    1              5               3         1 Initial qualifying events                                0                 0
3                    1              2               2         2 Not missing record date                                  0                 0
4                    1              2               2         3 Record in observation                                    0                 0
5                    1              2               2         4 Distinct measurement records                             0                 0

[edward-burn]

@nmercadeb I feel like this is a little vague, could it be a bit clearer why records are being dropped?

[nmercadeb]

This is when we filter to measurements that recorded a certain outcome/value, but I was not sure whether this should be a separate attrition entrance since maybe t should be included in the "Initial qualifying events"?

[edward-burn]

I think i would not include it