Corneal Collagen Cross-Linking in the Management of Keratoconus in Canada: A Cost-Effectiveness Analysis.

PURPOSE: To use patient-level microsimulation models to evaluate the comparative cost-effectiveness of early corneal cross-linking (CXL) and conventional management with penetrating keratoplasty (PKP) when indicated in managing keratoconus in Canada. DESIGN: Cost-utility analysis using individual-based, state-transition microsimulation models. PARTICIPANTS: Simulated cohorts of 100 000 individuals with keratoconus who entered each treatment arm at 25 years of age. Fellow eyes were modeled separately. Simulated individuals lived up to a maximum of 110 years. METHODS: We developed 2 state-transition microsimulation models to reflect the natural history of keratoconus progression and the impact of conventional management with PKP versus CXL. We collected data from the published literature to inform model parameters. We used realistic parameters that maximized the potential costs and complications of CXL, while minimizing those associated with PKP. In each treatment arm, we allowed simulated individuals to move through health states in monthly cycles from diagnosis until death. MAIN OUTCOME MEASURES: For each treatment strategy, we calculated the total cost and number of quality-adjusted life years (QALYs) gained. Costs were measured in Canadian dollars. Costs and QALYs were discounted at 5%, converting future costs and QALYs into present values. We used an incremental cost-effectiveness ratio (ICER = difference in lifetime costs/difference in lifetime health outcomes) to compare the cost-effectiveness of CXL versus conventional management with PKP. RESULTS: Lifetime costs and QALYs for CXL were estimated to be Can$5530 (Can$4512, discounted) and 50.12 QALYs (16.42 QALYs, discounted). Lifetime costs and QALYs for conventional management with PKP were Can$2675 (Can$1508, discounted) and 48.93 QALYs (16.09 QALYs, discounted). The discounted ICER comparing CXL to conventional management was Can$9090/QALY gained. Sensitivity analyses revealed that in general, parameter variations did not influence the cost-effectiveness of CXL. CONCLUSIONS: CXL is cost-effective compared with conventional management with PKP in the treatment of keratoconus. Our ICER of Can$9090/QALY falls well below the range of Can$20 000 to Can$100 000/QALY and below US$50 000/QALY, thresholds generally used to evaluate the cost-effectiveness of health interventions in Canada and the United States. This study provides strong economic evidence for the cost-effectiveness of early CXL in keratoconus.

Cost-Effectiveness Analysis of Corneal Collagen Crosslinking for Progressive Keratoconus.

PURPOSE: To evaluate the cost effectiveness of corneal collagen crosslinking (CXL) for progressive keratoconus from the healthcare payer's perspective. DESIGN: A probabilistic Markov-type model using data from published clinical trials and cohort studies. PARTICIPANTS: Two identical cohorts, each comprising 1000 virtual patients with progressive bilateral keratoconus, were modeled; one cohort underwent CXL and the other cohort received no intervention. METHODS: Both cohorts were modeled and evaluated annually over a lifetime. Quality-adjusted life years (QALYs), total cost, disease progression, and the probability of corneal transplantation, graft failure, or both were calculated based on data from published trials and cohort studies. These outcomes were compared between the 2 cohorts. In our base scenario, the stabilizing effect of CXL was assumed to be 10 years; however, longer durations also were analyzed. One-way sensitivity analyses were performed to test the robustness of the outcomes. MAIN OUTCOME MEASURE: Incremental cost-effectiveness ratio (ICER), defined as euros per QALY. RESULTS: Assuming a 10-year effect of CXL, the ICER was €54 384/QALY ($59 822/QALY). When we adjusted the effect of CXL to a lifelong stabilizing effect, the ICER decreased to €10 149/QALY ($11 163/QALY). Other sensitivity and scenario analyses that had a relevant impact on ICER included the discount rate, visual acuity before CXL, and healthcare costs. CONCLUSIONS: Corneal collagen crosslinking for progressive keratoconus is cost effective at a willingness-to-pay threshold of 3 times the current gross domestic product (GDP) per capita. Moreover, a longer stabilizing effect of CXL increases cost effectiveness. If CXL had a stabilizing effect on keratoconus of 15 years or longer, then the ICER would be less than the 1 × GDP per capita threshold and thus very cost effective.