Factors affecting the efficacy and safety of phosphodiesterase 5 inhibitor and placebo in treatment for lower urinary tract symptoms: meta-analysis and meta-regression.

Purpose: We aimed to investigate the real benefit and safety of phosphodiesterase 5 inhibitor (PDE 5I) for benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) by determining the affecting factors and to overcome the previous meta-analysis studies.

Methods: We conducted a systematic review of improvements in LUTS using International Prostate Symptom Score (IPSS), voiding subscore of IPSS (voiding IPSS), storage subscore of IPSS (storage IPSS), quality of life (QoL), maximal urinary flow rate (Qmax), and post-voided residual volume (PVR), and also investigated adverse events and relevant withdrawal rate.

Results: Final included studies were 28 studies with 19,820 subjects (9800 treatment group and 10,020 control group). The overall weighted mean differences of total IPSS, voiding IPSS, storage IPSS, and QoL showed significant improvement. Single placebo group showed significant improvement in all outcomes except PVR. The weighted prevalence of overall withdrawal rate and adverse event-specific withdrawal rate was 10 and 3%, respectively. Meta-regression showed that baseline IPSS, dosage of PDE 5I, and country affect clinical improvement compared with placebo.

Conclusions: This study clarifies the efficacy of PDE 5I on treatment of BPH/LUTS as an initial treatment strategy. However, baseline IPSS, dosage of PDE 5I and country affected the clinical improvement. Moreover, adverse event-specific withdrawal rate was not as high as suspected based on the overall withdrawal rate.