Prostate Health Index

**Semantic type:** Laboratory Procedure

**Definition:** An assay system that indirectly measures the amount of three forms of prostate-specific antigen (PSA) in a patient serum sample and then uses those values to calculate a score that estimates the patient's probability of having prostate cancer. The PSA forms that are examined are total PSA, free PSA, and an isoform of PSA that has a propeptide comprised of two amino acid residues ([-2]proPSA).

**Synonyms:** - PHI - phi-index