Aim: To develop a model to evaluate the cost-utility of choroidal nevi monitoring recommendations with varying clinical risk factors.
Methods: A Markov model was created to evaluate the cost-utility in cost per quality-adjusted life-year ($/QALY) for monitoring patients with choroidal nevus. This probabilistic model was applied both to a hypothetically monitored and unmonitored group of patients beginning at different ages and with varying clinical risk factors of the nevus. Duration of screening was modeled for the remainder of the patients' life expectancy. Best available clinical data on the prevalence and incidence of choroidal nevi/melanoma, and relative risk of nevus transformation were combined with the initial and downstream costs of screening, downstream costs of melanoma-related mortality, and QALY saved by monitoring, to estimate the best monitoring regimen. Main outcome measures were average $/QALY saved by consensus recommended monitoring scenarios for the duration of a patient's remaining life expectancy in comparison with no follow-up, and the cost-utility of modified regimens.
Results: The $/QALY of the recommended monitoring scenarios varied substantially based on nevus clinical risk factors, patient age, frequency of follow-up, and objective testing utilized. The $/QALY for the recommended monitoring scenario of a flat nevus without risk factors in a 60-year-old patient was $77 180. The $/QALY for monitoring a nevus with 3 clinical risk factors in a 60-year-old patient was $85 393. The $/QALY values for differently-aged patients were larger, and intermediate degrees of risk factors for nevus growth varied, depending largely upon the specifics of the modeled monitoring scenarios.
Conclusion: The average $/QALY of currently recommended monitoring scenarios fall within economically acceptable standards and could provide insight for formulating appropriate clinical strategies. Cost-utility could be enhanced by targeting higher risk groups and considering less frequent monitoring for the lower risk groups.
Keywords: Markov modeling; choroidal melanoma; choroidal nevus; cost-utility; screening.