Introduction:
Prostate-specific antigen (PSA) is an established biomarker for prostate cancer diagnosis and follow-up. In hospitalized patients, however, PSA testing is frequently performed outside recommended indications, often during acute illness, when transient PSA elevations are common. Previous studies report high rates of inappropriate inpatient PSA testing, low diagnostic yield, and minimal impact on clinical management. This study aimed to evaluate the appropriateness and downstream effects of inpatient PSA testing.

Materials and Methods:
We conducted a retrospective observational study including all inpatient PSA requests between January 1, 2024, and December 15, 2025, at our centre. Clinical data were obtained from electronic medical records. PSA testing was considered appropriate when performed after abnormal digital rectal examination (DRE); for investigation of suspected metastatic malignancy of prostatic or unknown origin; for lower urinary tract symptoms after appropriate counselling; or for monitoring of known prostate cancer with diagnostic, prognostic, or therapeutic implications.

Results:
A total of 906 inpatient PSA determinations were analyzed, predominantly requested by medical specialties (90.5%). Mean age was 72.0 ± 13.4 years and mean PSA was 12.1 ng/mL. PSA testing was repeated in 121 patients (13.4%).
The most frequent clinical indications cited were urinary tract infection (27.2%), suspected metastatic malignancy of prostatic or unknown origin (8.6%), and acute kidney injury (4.3%), while in 24.2% of cases no clinical justification was documented.
Only 100 requests (11.0%) met appropriateness criteria.
Downstream consequences occurred in 149 patients (16.4%), mainly referral to outpatient urology consultation (91 patients; 10.0%). Clinically meaningful management changes occurred in only 20 patients (2.2%), including multidisciplinary tumor board discussion in 15 (1.7%). New prostate cancer diagnoses attributable to inpatient PSA testing occurred in 10 patients (1.1%).

Conclusions:
Inpatient PSA testing demonstrated very low clinical value, with the majority of requests deemed inappropriate and very few resulting in clinically meaningful management changes, in line with previously published inpatient studies. Targeted educational strategies and institutional testing protocols are needed to reduce low-value inpatient PSA testing and optimize healthcare resource utilization.

Keywords: Prostate-specific antigen; Prostate cancer; Inpatient testing