Original Title: Revisión sistemática y análisis coste-efectividad del cribado de retinopatía diabética con retinógrafo no midriático de 45º mediante imágenes interpretadas por oftalmólogos frente a médicos de familia

Authors' objectives: The aim of this study was to perform a systematic review of the effectiveness and cost-effectiveness of different screening strategies for diabetic retinopathy (DR), as well as a cost-utility analysis of screening, treatment and intervals for DR in patients with diabetes mellitus type 1 (DM1) and 2 (DM2) by comparison of digital retinal images obtained with a non-mydriatic retinal camera graded by trained family practitioners for the presence of DR and graded by ophthalmologists for the presence of sight-threatening diabetic retinopathy (that needs treatment laser) versus the standard method (biomicroscopy and mydriatic indirect ophthalmoscopy). The analysis was performed from the social and health services perspectives. The study uses data from different sources of information inside a Markov model in terms of quality-adjusted lifeyears (QALYs) gained in patients with DR.

Authors' results and conclusions: RESULTS: The evidences found on effectiveness of different screening protocols for DR by means of a non-mydriatic retinal camera were obtained from observational cross-sectional studies. Those studies provided evidences of validity of different screening protocols for DR considering several cavariates (photographic angle, number of fundus fields, with or without previous pharmacologic mydriasis, grader of the images, and gold standard). In general, a screening protocol based on a non-mydriatic retinal camera was a valid procedure for screening for DR with a sensitivity and specificity greater than 80% and 90%, respectively. The incremental cost per QALY gained in patients with DR for the screening protocol based on digital images graded by trained family practitioners was of savings after including all costs (direct costs for health services, direct costs for the patient and productivity loss) considering a yearly discount rate of 3% for costs and utilities and of 2,030 € (2,030 €, 1,844 € and 1,740 € per QALY gained for screening intervals of 1, 2 and 3 years, respectively) after including only health services costs for patients with DM1 in a 10-year period. The incremental cost per QALY gained in patients with DR for the screening protocol based on digital images graded by trained family practitioners was of savings after including all costs (direct costs for health services, direct costs for the patient and productivity loss) considering a yearly discount rate of 3% for costs and utilities and of 2,812 € (2,812 €, 2,423 € and 2,288 € per QALY gained for screening intervals of 1, 2 and 3 years, respectively) after including only health services costs for patients with DM2 in a 10-year period. A sensitivity analysis of the estimates revealed that the parameter that generated greater uncertainty on cost-utility results was the utility or quality of life for blindness. CONCLUSIONS: The systematic review of the published literature about screening protocols for DR revealed that those based on a digital non-mydriatic retinal camera (with or without previous pharmacologic mydriasis) were a valid procedure for screening for DR. It remains unclear whether the discomfort caused by the use of previous pharmacologic mydriasis (and consequently a lower patient compliance with the screening program) may compensate its use or not. A screening protocol for DR based on digital fundus images graded by trained family practitioners seems to be cost-effective. Besides, cost-utility estimates from the present study are under the threshold considered by several health economic studies recently published in Spain. This analysis was performed from a health services perspective as well as from a social perspective because many costs come from outside the health care system. A screening protocol for DR based on digital fundus images graded by trained family practitioners seems to be more cost-effective that standards procedures. Moreover, changing the screening interval for DR from 1 to 3 years in patients free of DR is even more cost-effective. This report supports the use of a screening protocol for DR based on digital fundus images graded by trained family practitioners every 3 years in patients free of DR.

Authors' methods: This study was based on two different methodological procedures: a) a systematic review of the literature about the effectiveness and costeffectiveness of different screening protocols for DR, and b) a Markov model with six different health states (no DR, DR, clinically significant macular edema, proliferative DR, blindness and death) based on the natural history of the disease. Cost-utilities related to recruitment, screening, treatment and screening intervals for DR (1, 2 and 3 years) were estimated. Effectiveness was measured in terms of qualityadjusted life-years (QALYs) gained in patients with DR. Transition probabilities were obtained from previously published studies. Test sensitivity and specificity, costs and utilities were obtained from three cross-sectional studies that had been previously performed in the Autonomous Community of Canary Islands.

Project Status: Completed

Year Published: 2007

URL for published report: https://sescs.es/revision-sistematica-y-analisis-coste-efectividad-del-cribado-de-retinopatia-diabetica/

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: Spain

Organisation Name: Canary Health Service

Contact Address: Dirección del Servicio. Servicio Canario de la Salud, Camino Candelaria 44, 1ª planta, 38109 El Rosario, Santa Cruz de Tenerife

Contact Name: sescs@sescs.es

Contact Email: sescs@sescs.es