Mittmann and colleagues (2005; Canada) determined the cost-effectiveness of the oral erectile dysfunction treatment sildenafil citrate, compared to the following non-oral treatments: intracavernous injections of papaverine prostadil, alprostadil with papaverine and phentolamine (triple mix), transurethral suppository, surgically implanted rigid, semi-rigid, or inflatable prosthetic device and vacuum erection devices. There was a comparison of health preferences through the calculation of utilities and costs between the treatments over a one year period. Utility inputs were collected from interviews of a cohort of individuals with SCI. Costs were estimated through clinical scenarios based on standard of care at a rehabilitation facility and confirmed through an expert panel. Total costs for one year was most expensive for the surgically implanted prosthetic device, followed by transurethral suppository, intracavernous injections of papaverine prostadil, sildenafil citrate, and then triple mix. Vacuum erectile devices were the least expensive. Utility values were highest for sildenafil citrate and lowest for surgically implanted prosthetic devices. Sildenafil citrate was less expensive and had better utilities than intracavernous injections of papaverine prostadil, transurethral suppository and surgery. When both cost and effects were incorporated, sildenafil citrate had a cost per QALY of $9,656 compared to triple mix and $13,399 compared to vacuum erectile device. This study was limited to a one year timeframe and did not look at long-term outcomes due to the absence of data. The authors concluded that sildenafil citrate should be considered for inclusion in the Ontario public drug formulary and thus reimbursed for individuals in the Ontario drug beneficiary program.
In one study, sildenafil had lower cost and better outcomes than intracavernous injections, suppositories and surgery. Cost per QALY was $9,656/QALY for Triple Mix intercavernous injections and $13,399/QALY for vacuum erection device.