Variables Associated with False-Positive PSA Results: A Cohort Study with Real-World Data.

(1) Background: There are no real-world data evaluating the incidence of false-positive results. We analyzed the clinical and analytical factors associated with the presence of false-positive results in PSA determinations in practice. (2) Methods: A prospective cohort study of patients with a PSA test was performed in clinical practice. We followed the patients by reviewing their medical records for 2 years or until the diagnosis of PCa was reached, whichever came first. (3) Results: False-positive PSA rate was 46.8% (95% CI 44.2-49.2%) and false-negative PSA rate was 2.8% (95% CI 2-3.5%). Patients aged 61-70 years and those over 70 years were more likely to have a false-positive result than those under 45 years (aOR 2.83, 95% CI 1.06-7.55, p = 0.038, and aOR 4.62, 95% CI 1.75-12.22, p = 0.002, respectively). Patients with urinary tract infection were more likely to have a false-positive result (aOR 8.42, 95% CI 2.42-29.34, p = 0.001). Patients with diabetes mellitus were less likely to have a false-positive result (aOR 0.63, 95% CI 0.41-0.98, p = 0.038); (4) Conclusions: This study has generated relevant information that could be very useful for shared decision making in clinical practice.