BACKGROUND
Erectile dysfunction (ED) is a common male sexual disorder worldwide. Three oral phosphodiesterase type 5 inhibitors (PDE5Is) - sildenafil, tadalafil and vardenafil - are available for treatment of ED. This study quantitatively evaluated the therapeutic efficacy and safety of these medications to assist treatment decision making.
METHODS
We used multiple criteria decision analysis (MCDA) to assess the totality of risk-benefit of PDE5Is. We created two models: (i) the overall model included 'overall improvement in erections' and 'any adverse events' and (ii) the detailed model included 'erectile function domain', 'ability for sexual intercourse', 'duration of erection last', 'serious adverse events', 'headache', 'flushing' and 'dyspepsia'. We calculated a synthetic utility for each drug accounting for all of its benefits and risks.
RESULTS
Considering the overall risk-benefit, vardenafil had the highest synthetic utility among three medications; in the order of synthetic utilities: vardenafil (0.568), tadalafil (0.478) and sildenafil (0.437). However, when specific risk and benefit criteria were assessed, tadalafil had the highest synthetic utility (0.602) according to the conjoint evaluation (synthetic utility for vardenafil is 0.491 and sildenafil is 0.442, respectively). The sensitivity analysis based on the uncertainties of weight on risks of any adverse events (including serious adverse events and headache) suggested our results were robust.
CONCLUSIONS
This study provides a useful approach that comprehensively and systematically assesses and compares the risk-benefit of several treatment alternatives. Our study not only rank treatment alternatives by synthetic utilities based on the risk-benefit balance but also compare specific risk and benefit criteria between these medicines. Our results provide valuable evidence that can guide clinicians and patients in making treatment decisions.