Abstract
OBJECTIVE: Sweden has a long-standing tradition of actively managing infants born extremely preterm at 22-23 weeks' gestational age. This study analyses screening and treatment pathways for retinopathy of prematurity (ROP) in these infants, assessing costs and health outcomes to develop a model of direct healthcare costs. METHOD AND ANALYSIS: The cohort included all 399 infants born at 22-23 weeks in Sweden (2007-2018) who underwent ROP screening, recorded in the national ROP registry SWEDROP. A health economic model estimated costs based on three primary pathways: (1) no sight-saving treatment, (2) laser as initial treatment and (3) anti-vascular endothelial growth factor (anti-VEGF) as initial treatment. Pathways 2 and 3 were further divided into single and multiple treatments. Costs were calculated using screening frequency, treatment and neonatal care expenses. Register data were verified against medical records. An expanded model incorporated gestational age and comorbidities. RESULTS: In the basic model, 36% received laser (16 screenings on average; 32% required retreatment), while 7% received anti-VEGF injections (25 screenings; 69% required retreatment). The cost of screening and treating an infant with laser was Int$ 18 590, compared with Int$ 20 792 for anti-VEGF. The expanded models showed similar screening and treatment frequencies. CONCLUSION: Despite similar overall costs, the higher screening burden in the anti-VEGF group (25 vs 16 screenings) raises concerns regarding cost-effectiveness and potential health impacts. Main limitations include the use of cost data from a single hospital, potential selection bias between treatment groups and limited precision in small subgroups. These findings lay the groundwork for future research on long-term health and cost outcomes in this vulnerable population.