Cost effectiveness of photodynamic therapy with verteporfin for age related macular degeneration: the UK case.

AIM

To estimate the potential cost effectiveness of photodynamic therapy (PDT) with verteporfin in the UK setting.

METHODS

Using data from a variety of sources a Markov model was built to produce estimates of the cost effectiveness (incremental cost per quality adjusted life year (QALY) and incremental cost per vision year gained) of PDT for two cohorts of patients (one with starting visual acuity (VA) of 20/40 and one at 20/100) with predominantly classic choroidal neovascular disease over a 2 year and 5 year time horizon. A government perspective and a treatment cost only perspective were considered. Probabilistic and one way sensitivity analyses were undertaken.

RESULTS

From the government perspective, over the 2 year period, the expected incremental cost effectiveness ratios range from 286 000 (starting VA 20/100) to 76 000 UK pounds (starting VA 20/40) per QALY gained and from 14 000 (20/100) to 34 000 UK pounds (20/40) per vision year gained. A 5 year perspective yields incremental ratios less than 5000 UK pounds for vision years gained and from 9000 (20/40) to 30 000 UK pounds (20/100) for QALYs gained. Without societal or NHS cost offsets included, the 2 year incremental cost per vision year gained ranges from 20 000 (20/100) to 40 000 UK pounds (20/40), and the 2 year incremental cost per QALY gained ranges from 412 000 (20/100) to 90 000 UK pounds (20/40). The 5 year time frame shows expected costs of 7000 (20/40) to 10 000 UK pounds (20/100) per vision year gained and from 38 000 (20/40) to 69 000 UK pounds (20/100) per QALY gained.

CONCLUSION

This evaluation suggests that early treatment (that is, treating eyes at less severe stages of disease) with PDT leads to increased efficiency. When considering only the cost of therapy, treating people at lower levels of visual acuity would probably not be considered cost effective. However, a broad perspective that incorporates other NHS treatment costs and social care costs suggests that over a long period of time, PDT may yield reasonable value for money.