Authors' objectives:

The aim of this study was to estimate the cost-effectiveness of screening for AMD by developing a decision analytic model that incorporated and assessed all of the above criteria. At the outset it was recognised that there was likely to be significant uncertainty in key areas of the model, and an objective of the study was to identify the major areas of uncertainty, and so inform future research priorities in this disease area.

Authors' results and conclusions: There remains significant uncertainty about whether any form of screening for AMD is cost-effective. However, annual screening from age 60 years seems to provide the highest mean net benefits, but this is based on a cost-effectiveness estimate that has very poor precision (high levels of uncertainty). The probabilistic sensitivity analysis shows that the 95% credible interval for annual screening from age 60 years ranges from this option dominating the previous option to an incremental cost per QALY of over £0.5 million. Plotting a cost-effectiveness acceptability frontier shows that although annual screening from age 60 years has the highest net benefits at a value of QALY of £30,000, the associated probability of this option being the most cost-effective option is only around 20%. The sensitivity analyses around potential future treatment options indicate that screening may become more cost-effective with the new treatments.

Authors' recommendations: The conclusions focus on the interpretation of the results from the perspective of defining the major areas of uncertainty, which were defined as: Disease progression (due to the available data, the model was built around progression of visual acuity, despite a preference for contrast sensitivity). Rates of clinical presentation (informed by local data from the Sheffield photodynamic therapy (PDT) clinic and responses from a survey of general ophthalmologists). Problems with this approach included a small sample of patients, the fact that the PDT database was not validated, a limited response to the survey of ophthalmologists and inconsistencies in the responses received. Screening test and optician effectiveness (elicited data described the probability that individuals undertaking the simple screening test at home who notice an abnormality would then present at an optician's). The model assumes that optometrists accurately refer all cases of dry and wet AMD on to hospital ophthalmologists, while not referring any cases of early ARM. Treatment effectiveness (a lack of long-term follow-up data inevitably requires the use of weak assumptions to extrapolate the observed effectiveness data). Costs of blindness (a binary threshold for costs associated with blindness was incorporated, but such costs would be more appropriately described on a continuum).Future research may be best targeted at assessing how routine data may be used to describe clinical presentation rates of ARM. Other potential studies include a pilot study of the effectiveness of screening and opticians' referral patterns for AMD and a costing study of blindness as a continuum of association with deterioration in vision.

Authors' methods: Economic evaluation

Project Status: Completed

URL for project: http://www.hta.ac.uk/1387

Year Published: 2008

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: England, United Kingdom

Organisation Name: NIHR Health Technology Assessment programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk

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