| ORT | object relations technique; operating room technician; oral rehydration therapy |
|---|---|
| OTA | occupational therapy assistant; Office of Technology Assessment; ornithine transaminase; orthotoluid... |
| PBT | Paul-Bunnell test; phenacetin breath test; piebald trait; profile-based therapy |
| PDT | photodynamic therapy; population doubling time |
| PhTD | Doctor of Physical Therapy |