Compliance with biopsy recommendations of a prostate cancer risk calculator

Abstract

Study Type - Diagnostic (cohort) Level of Evidence 2b What's known on the subject? and What does the study add? So far, few publications have shown that a prediction model influences the behaviour of both physicians and patients. To our knowledge, it was unknown whether urologists and patients are compliant with the recommendations of a prostate cancer risk calculator and their reasons for non-compliance. Recommendations of the European Randomized study of Screening for Prostate Cancer risk calculator (ERSPC RC) about the need of a prostate biopsy were followed in most patients. In most cases of non-compliance with 'no biopsy' recommendations, a PSA level ≥ 3 ng/mL was decisive to opt for biopsy. Before implementation of the ERSPC RC in urological practices at a large scale, it is important to obtain insight into the use of guidelines that might counteract the adoption of the use of the RC as a result of opposing recommendations.

Objectives: To assess both urologist and patient compliance with a 'no biopsy' or 'biopsy' recommendation of the European Randomized study of Screening for Prostate Cancer (ERSPC) Risk Calculator (RC), as well as their reasons for non-compliance. To assess determinants of patient compliance.

Patients and methods: The ERSPC RC calculates the probability on a positive sextant prostate biopsy (P(posb) ) using serum prostate-specific antigen (PSA) level, outcomes of digital rectal examination and transrectal ultrasonography, and ultrasonographically assessed prostate volume. A biopsy was recommended if P(posb) ≥20%. Between 2008 and 2011, eight urologists from five Dutch hospitals included 443 patients (aged 55-75 years) after a PSA test with no previous biopsy. Urologists calculated the P(posb) using the RC in the presence of patients and completed a questionnaire about compliance. Patients completed a questionnaire about prostate cancer knowledge, attitude towards prostate biopsy, self-rated health (12-Item Short Form Health Survey), anxiety (State Trait Anxiety Inventory-6, Memorial Anxiety Scale for Prostate Cancer) and decision-making measures (Decisional Conflict Scale).

Results: Both urologists and patients complied with the RC recommendation in 368 of 443 (83%) cases. If a biopsy was recommended, almost all patients (96%; 257/269) complied, although 63 of the 174 (36%) patients were biopsied against the recommendation of the RC. Compliers with a 'no biopsy' recommendation had a lower mean P(posb) than non-compliers (9% vs 14%; P < 0.001). Urologists opted for biopsies against the recommendations of the RC because of an elevated PSA level (≥ 3 ng/mL) (78%; 49/63) and patients because they wanted certainty (60%; 38/63).

Conclusions: Recommendations of the ERSPC RC on prostate biopsy were followed in most patients. The RC hence may be a promising tool for supporting clinical decision-making.