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Title: An evaluation of the effectiveness and cost-effectiveness of screening for diabetic retinopathy by digital imaging photography and technician ophthalmoscopy and the subsequent change in activity, workload and costs of new diabetic ophthalmology referrals
Author: Scanlon, Peter Henry
ISNI:       0000 0001 3554 7493
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2005
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Aims: 1) To validate an Ophthalmologists reference standard examination. 2) To evaluate the effectiveness and cost-effectiveness of the introduction of a community based non-mydriatic and mydriatic digital photographic screening programme for diabetic retinopathy. 3) To determine the subsequent change in workload of the Ophthalmology Department. Methods: 1) An Ophthalmologist's examination was compared prospectively with 7-field stereo-photography in 239 persons. 2) 3611 patients attending general practices in Gloucestershire had one-field, non-mydriatic and mydriatic two-field digital photography. 1549 of these patients were examined by an Ophthalmologist. A cost effectiveness analysis was undertaken. 3) A retrospective study of Eye clinic workload was performed for the year before screening commenced, 2 years of the first round and the first year of the second round. Results: 1) In comparison with 7-field stereo photography, the Ophthalmologist's examination gave a sensitivity of 87.4% (confidence interval 83.5-91.5%) and a specificity of 94.9% (91.5-98.3%). 2) For mydriatic digital photography, the sensitivity was 87.8%, specificity was 86.1% and technical failure rate was 3.7%. For non-mydriatic photography, the sensitivity was 86.0%, specificity was 76.7% and technical failure rate was 19.7%. The best estimate of cost per true positive detected was 429 (range 394-473) for mydriatic and 490 ( 450-535) for non-mydriatic photography. 3) The annual referral rate and the number with diabetes in the county increased over the four years and only reduced in the fourth year for laser treatment sessions (171,282, 265, 199). Conclusions: Two-field mydriatic digital photography is an effective and cost-effective method of screening for referable diabetic retinopathy whereas non-mydriatic digital photography has an unacceptable technical failure rate and low specificity. The consequent workload in the Eye clinic increased in the first round of screening but, with increasing numbers of people with diabetes, did not fall below the pre-screening level, except for laser treatment.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available