Table 4.

Costs and effects of treatment with sildenafil and papaverine-phentolamine injection and difference between two treatments

Year	Successfully treated patients (%)		Incremental cumulative effects (QALY)	Incremental cumulative costs (£)	Incremental cost utility ratio (£/QALY)
	Sildenafil	Injection
1	77.25	6.40	7.79	28 368	3639
2	69.53	5.50	14.84	44 773	3017
3	66.05	5.23	21.53	60 356	2803
4	62.75	4.97	27.88	75 161	2695
5	59.61	4.72	33.92	89 226	2630
∞*					2329

^*In year N the incremental cost utility ratio is a function of the incremental cumulative costs divided by incremental cumulative effects over these N years. But if you look at the cost utility ratios in the first and second year separately, you get an incremental cost utility ratio of £3639 per QALY in the first year and £2329 per QALY in the second year. The incremental cost utility ratio is constant from the second year on: £2329 per QALY. So, in the long term, the influence of the first year treatment costs is diminishing and the incremental cost utility ratio approaches £2329 per QALY.