| PERK | prospective evaluation of radial keratotomy [protocol] |
|---|---|
| PIOPED | Prospective Investigation of Pulmonary Embolism Diagnosis [data base] |
| PRAISE | Prospective Randomized Amlodipine Survival Evaluation |
| PREDICT | Prospective Randomized Evaluation of Diltiazem CD Trial |
| ProPAC | Prospective Payment Assessment Commission |