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Keywords:

  • prostate-specific antigen (PSA);
  • prostate health index (phi);
  • free PSA;
  • PSA precursor form [−2]proPSA;
  • cost-effectiveness analysis

Study Type – Diagnostic (cost effectiveness)

Level of Evidence 2b

What's known on the subject? and What does the study add?

The Beckman Coulter prostate health index (phi) was developed as a combination of serum prostate specific antigen (PSA), free PSA and a PSA precursor form [−2]proPSA to calculate the probability of prostate cancer and was used as an aid in distinguishing prostate cancer from benign prostatic conditions for men with PSA test 2–10 ng/mL and non-suspicious digital rectal examination. Phi has been shown to improve diagnostic accuracy in prostate cancer detection compared with total and free PSA. An earlier 1-year budget impact analysis revealed it to be a complementary approach to current prostate cancer screening strategies.

The current study evaluated the cost-effectiveness of early prostate cancer detection with phi in combination with a PSA test compared with a PSA test alone from the US societal perspective. The model with over 25 annual screening cycles for men aged 50–75 years indicated that PSA plus phi dominated the PSA test alone in prostate cancer detection and consequent treatment. PSA plus phi may be an important strategy for prostate cancer detection.

OBJECTIVE

  • • 
    To evaluate the cost-effectiveness of early prostate cancer detection with the Beckman Coulter Prostate Health Index (phi) (not currently available in the USA) adding to the serum prostate-specific antigen (PSA) test compared with the PSA test alone from the US societal perspective.

PATIENTS AND METHODS

  • • 
    Phi was developed as a combination of PSA, free PSA, and a PSA precursor form [−2]proPSA to calculate the probability of prostate cancer and was used as an aid in distinguishing prostate cancer from benign prostatic conditions for men with a borderline PSA test (e.g. PSA 2–10 ng/mL or 4–10 ng/mL) and non-suspicious digital rectal examination.
  • • 
    We constructed a Markov model with probabilistic sensitivity analysis to estimate expected costs and utilities of prostate cancer detection and consequent treatment for the annual prostate cancer screening in the male population aged 50–75 years old.
  • • 
    The transition probabilities, health state utilities and prostate cancer treatment costs were derived from the published literature. The diagnostic performance of phi was obtained from a multi-centre study. Diagnostic related costs were obtained from the 2009 Medicare Fee Schedule.
  • • 
    Cost-effectiveness was compared between the strategies of PSA test alone and PSA plus phi under two PSA thresholds (≥2 ng/mL and ≥4 ng/mL) to recommend a prostate biopsy.

RESULTS

  • • 
    Over 25 annual screening cycles, the strategy of PSA plus phi dominated the PSA-only strategy using both thresholds of PSA ≥2 ng/mL and PSA ≥4 ng/mL, and was estimated to save $1199 or $443, with an expected gain of 0.08 or 0.03 quality adjusted life years, respectively.
  • • 
    The probabilities of PSA plus phi being cost effective were approximately 77–70% or 78–71% at a range of $0–$200 000 willingness to pay using PSA thresholds ≥2 ng/mL and ≥4 ng/mL, respectively.

CONCLUSION

  • • 
    The strategy PSA plus phi may be an important strategy for prostate cancer detection at both thresholds of PSA ≥2 ng/mL and PSA ≥4 ng/mL to recommend a prostate biopsy compared with using PSA alone.