Diffusion of anti-VEGF injections in the Portuguese National Health System.

OBJECTIVES: To analyse the temporal and geographical diffusion of antivascular endothelial growth factor (anti-VEGF) interventions, and its determinants in a National Health System (NHS). SETTING: NHS Portuguese hospitals. PARTICIPANTS: All inpatient and day cases related to eye diseases at all Portuguese public hospitals for the period 2002-2012 were selected on the basis of four International Classification of Diseases 9th revision, Clinical Modification (ICD-9-CM) codes for procedures: 1474, 1475, 1479 and 149. PRIMARY AND SECONDARY OUTCOME MEASURES: We measured anti-VEGF treatment rates by year and county. The determinants of the geographical diffusion were investigated using generalised linear modelling. RESULTS: We analysed all hospital discharges from all NHS hospitals in Portugal (98,408 hospital discharges corresponding to 57,984 patients). National rates of hospitals episodes for the codes for procedures used were low before anti-VEGF approval in 2007 (less than 12% of hospital discharges). Between 2007 and 2012, the rates of hospital episodes related to the introduction of anti-VEGF injections increased by 27% per year. Patients from areas without ophthalmology departments received fewer treatments than those from areas with ophthalmology departments. The availability of an ophthalmology department in the county increased the rates of hospital episodes by 243%, and a 100-persons greater density per km(2) raised the rates by 11%. CONCLUSIONS: Our study shows a large but unequal diffusion of anti-VEGF treatments despite the universal coverage and very low copayments. The technological innovation in ophthalmology may thus produce unexpected inequalities related to financial constraints unless the implementation of innovative techniques is planned and regulated.