Trends, geographical variation and factors associated with the use of anti-VEGF intravitreal injections in Portugal (2013-2018): a retrospective analysis of administrative data.

AIMS: The arrival of anti-vascular endothelial growth factor (anti-VEGF) therapies represented a treatment shift for several ophthalmological disorders and led to an increasing number of patients undergoing intravitreal injections. The aims of this observational study were to assess the expansion of anti-VEGF intravitreal injections in the Portuguese National Health System (NHS) and to identify factors correlated with geographical variations in episode rates. METHODS: Administrative database on discharge from Portuguese NHS hospitals was analysed for annual values and rates of intravitreal anti-VEGF injections at a national and regional level, between 2013 and 2018. RESULTS: The number of episodes of anti-VEGF treatment and patients treated increased 16% and 9% per year, respectively, between 2013 and 2018. During the study period around 72% of patients were treated in the Metropolitan areas of Lisbon and Porto and in the Central region. Intravitreal anti-VEGF treatment rates in 2018 were 560 per 100 000 population and presented high variability between municipalities. Higher anti-VEGF treatment rates at the municipality level were associated with shorter distances between their residence and the hospital. At the hospital level, higher ratio of ophthalmologists and higher organisational level were associated with higher anti-VEGF treatment rates. CONCLUSION: The number of episodes and patients treated with anti-VEGF injections has been growing in recent years. Proximity to healthcare, more access to ophthalmologists and hospitals with higher organisational levels are associated with higher anti-VEGF treatment rates. Improving access is crucial to reduce regional discrepancies and ensure optimal treatment frequency, which may improve health outcomes.