Cost utility analysis of sildenafil compared with papaverine-phentolamine injections
Valuing the effects of sildenafil in erectile dysfuntion [Editorial]
Viagra (sildenafil) is cost effective and should be more widely available on prescription, contends a cost-benefit analysis in this week's BMJ.
Stolk and colleagues from the Institute for Medical Technology Assessment in Rotterdam, The Netherlands, compared the costs and effects of Viagra pills with injections used once a week for the treatment of erectile dysfunction over a projected period of five years. The authors used clinical results from a large published trial, graded evaluations from 169 randomly selected members of the general public, and measured medical treatment, and societal costs to calculate the cost per quality adjusted life year (QALYs).
Treatment with Viagra was more expensive than treatment with injections, especially if used more than once a week. But viagra produced more QALYs, partly because more people are treated with it than with injections. Altogether, the ratio of cost to usefulness-cost utility ratio-worked out at £3639 for the first year of life gained, becoming less expensive each successive year. This, say the authors, is well within the accepted limits for such a ratio, usually put at between £8000 and £25,000. And, they add, less than the ratios for breast screening at almost £7000 per QALY and kidney transplantation at almost £5000 per QALY.
An accompanying editorial, however, by Nick Freemantle, of the Medicines Evaluation Group at the University of York, suggests that using QALYs to assess cost effectiveness is essentially flawed, because the method relies on too many assumptions and, in this context, is not comparing like with like. He points out that in the UK, the National Institute for Clinical Excellence (NICE) has not yet decided to use QALYs to inform its recommendations. Simply assessing each treatment on merit and making recommendations on the basis of clinical effectiveness and cost is a more honest and transparent approach, he suggests.
Contacts:
(For Paper) Dr Elly Stolk, Institute for Medical Technology Assessment, Erasmus University, Rotterdam, The Netherlands Email: stolk@bmg.eur.nl
(For Editorial) Dr Nick Freemantle, Centre for Health Economics, University of York Email: nf2@york.ac.uk