Cost-effectiveness: base case and sensitivity analyses*
| Assumption/parameter | Base case | Sensitivity analyses | Incremental cost | Incremental QALY | ICER | ICER (% change) |
| Ranibizumab monotherapy versus laser monotherapy | ||||||
| Base case | – | – | £4191 | 0.17 | £24 028 | – |
| Discount rate of future costs and benefits | 3.50% | 0%–5% | £3593–£4383 | 0.16 to 0.16 | £17 051–£27 042 | –29% to +13% |
| Time horizon | 15 years | 10–20 years | £4738–£3991 | 0.14 to 0.19 | £33 139 to £21 343 | +38% to –11% |
| Cost of blindness | £6477 | –25% to +25% | £4868–£3515 | 0.17 to 0.17 | £27 907–£20 150 | +16% to –16% |
| Long-term progression of VA | Declining | Constant or increasing | £4487–£4693 | 0.17 to 0.17 | £26 198–£28 413 | +9% to +18% |
| Total number of ranibizumab injections | 10 | –4 injections to +4 injections | £2171–£6774 | 0.17 to 0.17 | £12 446–38 836 | –48% to +62% |
| Baseline age | 63 years | 58 years | £3767 | 0.20 | £19 259 | –20% |
| Source of utilities | RESTORE | Lloyd et al12 | £4191 | 0.22 | £19 238 | –20% |
| RESTORE | Brown et al13 | £4191 | 0.19 | £21 953 | –9% | |
| Combination therapy versus laser monotherapy | ||||||
| Base case | – | – | £4695 | 0.13 | £36 106 | – |
| Discounting of future costs and benefits | 3.50% | 0%–5% | £4271–£4828 | 0.16 to 0.12 | £26 957–£40 096 | –25% to +11% |
| Time horizon | 15 years | 10–20 years | £5133–£4507 | 0.10 to 0.13 | £49 294–£34 135 | +37% to –5% |
| Cost of blindness | £6477 | –25% to +25% | £5050–4340 | 0.13 to 0.13 | £38 833–£33 378 | +8% to –8% |
| Long-term progression of VA | Declining | Constant or increasing | £5091–£5276 | 0.13 to 0.12 | £40 852–£44 071 | +13% to +22% |
| Total number of ranibizumab injections | 9 | –4 injections to +4 injections | £3165–£7260 | 0.13 to 0.13 | £24 340–£55 828 | –33% to +55% |
| Baseline age | 63 years | 58 years | £4393 | 0.15 | £29 952 | –17% |
| Source of utilities | RESTORE | Lloyd et al12 | £4695 | 0.16 | £28 778 | –20% |
| RESTORE | Brown et al13 | £4695 | 0.16 | £29 576 | –18% | |
↵* Incremental cost measures the additional cost of ranibizumab monotherapy or combination therapy compared with laser monotherapy in the modelled time horizon (15 years in base case). Incremental QALY measures the corresponding QALY gain when ranibizumab monotherapy or combination therapy is compared with laser monotherapy. The ICER is calculated by dividing the incremental cost by the incremental QALY. The ICER is interpreted as the cost of achieving an additional year of life in perfect health.
ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life-year; VA, visual acuity.