Cost-effectiveness of culture-guided antimicrobial prophylaxis for the prevention of infections after prostate biopsy

• Rectal culture-guided antimicrobial prophylaxis for transrectal ultrasound-guided prostate biopsy (TRUSBx) reduces the infection rate.
• A model-based analysis found culture-guided prophylaxis to be effective and cost-saving.
• Sensitivity analysis showed culture-guided prophylaxis to be robust.

SummaryBackgroundClinical findings suggest that the use of rectal culture-guided antibiotic prophylaxis reduces the infection rate following transrectal ultrasound-guided prostate biopsy (TRUSBx).MethodsA decision-analytic model was designed to compare the outcomes of TRUSBx performed with (rectal culture-guided group) and without (standard ciprofloxacin prophylaxis) rectal swab culture-guided antimicrobial prophylaxis in Hong Kong. The post-biopsy infection rate, infection-related costs, quality-adjusted life years (QALYs) lost for infection, and incremental cost per QALY saved (ICER) were assessed. Model inputs were retrieved from local epidemiology data and the medical literature. A sensitivity analysis was performed to test the robustness of the model results.ResultsBase-case analysis showed that the infection rate in the culture-guided group was reduced from 2.42% to 0.23% and saved 0.0002 QALYs, with a lower cost (USD 31.4 versus USD 55.6) (USD 1 = HKD 7.8). The number needed to screen to prevent an infection episode was 45.7. The hospital days avoided per 100 patients using culture-guided prophylaxis was 7.08 days. The relative effectiveness of culture-guided antimicrobial prophylaxis versus standard prophylaxis in carriers and non-carriers of FQ-resistant rectal flora were identified as potential influencing factors. In 10 000 Monte Carlo simulations, ICERs of the culture-guided group were below the willingness-to-pay threshold 99.12% of the time.ConclusionsUsing rectal culture-guided antimicrobial prophylaxis for men undergoing TRUSBx appears to be a cost-saving strategy to avert post-biopsy infection and QALY loss in Hong Kong.