Design: We developed a stochastic decision analytic model to assess the incremental cost of ET per eye with severe visual impairment prevented. We used the third party payer perspective. Resource utilization and efficacy were derived from ETROP published outcome data. We derived physician costs from insurance reimbursement rates and hospital costs from converted charges for equivalent services at tertiary care institutions, using department-specific Medicare cost-to-charge ratios. All costs were expressed in 2005 US dollars. Time horizon was from birth through nine months corrected gestational age, corresponding to the ETROP data collection period. Since the time horizon was less than 1 year, discounting was not undertaken. Parameter uncertainty was quantified using probabilistic sensitivity analysis to generate cost-effectiveness acceptability curves. We also performed deterministic sensitivity analyses to address uncertainty in key cost and resource assumptions.
Results: The base case revealed ET had an incremental cost-effectiveness ratio (ICER) of $14,200 per eye with severe visual impairment prevented. There was a 90% chance that this intervention would be considered cost-effective at a willingness-to-pay threshold of $40,000, a 0.5% chance that ET would be dominant (cost-saving), and a 2.1% chance that it would be dominated. Deterministic sensitivity analyses revealed the ICER was most sensitive to the cost of additional eye exams and to the cost of laser therapy, but was minimally sensitive to all other variables. In a “best-case” analysis, ET was cost-saving, while in a “worst-case” analysis the ICER was $50,500 per eye with severe visual impairment prevented.
Conclusions: The early treatment of retinopathy of prematurity is not only efficacious, but has an ICER well within the range of other commonly accepted interventions. Furthermore, given the high lifetime costs of severe visual impairment, the early treatment strategy would be expected to provide long-term cost savings.