Presentation (CTI)

OBJECTIVES: Intravitreal anti-VEGF injections require frequent hospital visits, imposing a transport burden on elderly patients and their caregivers. We aimed to quantify geographic variation in injection frequency across Danish municipalities, assess the resulting caregiver transport burden, and explore whether regional incentive structures and treatment protocols contribute to observed differences.
METHODS: We conducted an exploratory cross-sectional geospatial analysis using national registry data (Statistics Denmark, 2023-2025) covering all intravitreal injection contacts (procedure KCKD05B) across 98 Danish municipalities. Injection frequency was defined as contacts with a recorded injection procedure per patient-year, excluding monitoring-only visits. Road-network travel distances were computed using the Open Source Routing Machine (OSRM). Annual caregiver transport burden was estimated using health economic costing (WifOR methodology) including vehicle operation, caregiver opportunity cost, patient time, and 30 minutes per visit. Kruskal-Wallis and pairwise Mann-Whitney U tests assessed regional differences; p-values are nominal without multiplicity adjustment.
RESULTS: We identified 30,347 patients per year receiving 467,429 injection contacts across 10 treatment sites. Injection frequency varied from 3.15 to 7.27 contacts per patient-year across municipalities (Kruskal-Wallis H=74.7, p<0.001). Region Syddanmark (6.20/yr) and Region Nordjylland (6.07/yr) had significantly higher frequency than Region Sjælland (3.81/yr, p<0.001). Despite 15% shorter travel distances, Region Syddanmark patients had 46% higher annual transport burden (5,779 vs 3,951 DKK/patient/year). The national annual caregiver transport burden was estimated at 67-119 million DKK. Decomposition analysis showed injection frequency, not geographic distance, is the primary driver of burden inequality.
CONCLUSIONS: Injection frequency varies two-fold across Danish treatment sites. This frequency-driven inequality imposes a disproportionate transport burden on patients in Region Syddanmark, independent of geographic access. Regional incentive structures and differences in treatment protocols (e.g. treat-and-extend vs. observe-and-plan) are plausible drivers warranting further investigation.