Screening Plus Corneal Cross-Linking for Keratoconus Is Cost-Effective for New Zealand: A Proof-of-Concept Markov Analysis.

Abstract

Background: The prevalence of keratoconus in New Zealand is higher compared to the global prevalence of 1.38 per 1000, with Māori and Pacific Islander being over-represented. The form of keratoconus in New Zealand has been shown to have a more rapid progression of disease. In this study, we aimed to evaluate the cost-effectiveness of introducing screening for keratoconus in the New Zealand context, with corneal cross-linking as treatment for those screening positive.

Methods: A Markov simulation was used to model the impact of screening plus corneal cross-linking compared to usual care across a lifetime horizon and societal perspective with a 3% discount rate. Cost-effectiveness was determined by the incremental cost-effectiveness ratio, with utility measured in quality-adjusted life-years. Univariate and probabilistic sensitivity analyses were carried out to investigate factors influencing cost-effectiveness.

Results: The incremental cost-effectiveness for screening with corneal cross-linking treatment was -NZ$1278 (95% CI -1418, -1139) per QALY gained. Factors that had the most influence on incremental cost-effectiveness were the specificity of the screening test, the prevalence of keratoconus at the time of screening, the discount rate, the probability of patients who are progressors, adherence, and efficacy of cross-linking treatment.

Conclusion: Screening for keratoconus at age 15 with corneal cross-linking treatment for children who screened positive is likely to be cost saving. Our results support the need for a real-world trial and cost-effectiveness analysis in New Zealand to ensure that we identify and treat those at risk early in the disease course before significant vision loss has occurred.