Final answer:
The PDGM changed payment groupings based on therapy utilization and patient characteristics.
Step-by-step explanation:
The PDGM (Patient-Driven Groupings Model) changed payment groupings based on therapy utilization, which is option D.
Prior to the PDGM, Medicare payments were determined based on the number of therapy visits provided to a patient. However, under the PDGM, payments are now determined based on the patient's clinical characteristics and patient characteristics. The patient characteristics include the patient's diagnosis, functional level, and comorbidities.
In summary, the PDGM changed payment groupings based on the patient's therapy utilization and their clinical and patient characteristics, rather than just the number of visits.