Screening for diabetic retinopathy by optometrists: effectiveness and cost-effectiveness

This report examines the effectiveness and cost-effectiveness of screening for diabetic retinopathy by optometrists. There are strong arguments for screening. Diabetic retinopathy is an important public health problem, there is an effective treatment, the natural history of the disease is well understood, adequate and acceptable screening exists and the cost of case finding is small in relation to overall expenditure on the disease (Section 2). The major unresolved issue concerns the choice of screening modality i.e. who should perform screening, when and how. A literature search revealed 18 citations presenting data relating to screening by optometrists (Section 3). The only cost-effectiveness study of screening modalities directly relevant to the UK is the Special Medical Development Project (SMDP). Whilst an extensive study, the SMDP has a number of methodological weaknesses which made it inappropriate to conclude that one screening modality is more cost-effective than another (Section 3.2). Another British study, undertaken in Frenchay health district, provides starkly different evidence on the effectiveness of screening by optometrists (Section 3.4). The overall conclusion is that there are no ideal data for addressing the effectiveness and cost-effectiveness of optometrists in screening for diabetic retinopathy (Section 3.9). The selection of screening modalities for diabetic retinopathy needs to take account of the current environment for care. IN particular, the manner in which diabetics currently present to the health service would make a single modality of limited use (Section 4). Key features of the development of screening schemes include the role of training of practitioners, the development of protocols for care and sharing data, reimbursement and audit (Section 4). One way to resolve controversy would be to undertake a new prospective stuffy of optometrists in screening. However, a more pragmatic design, mirroring the current environment of care, may be important. Smaller trials investigating sub-issues and surveys of diabetics and potential screeners may produce a valuable backdrop in designing appropriate studies (Section 5).