A Method for Estimating Resource Use and Costs when Empirical Data Are Unavailable: Expert Elicitation Study Using the Example of Melanoma

Purpose. The diagnosis, management, and therapy of cancer are rapidly advancing and becoming more costly. Data linking the diagnosis, management, and prescription of systemic anticancer therapy (SACT) are not publicly available, are time-consuming to obtain, and are onerous to analyze. We aimed to illustrate how a simple expert elicitation method can be used rapidly to calculate the cost of diagnosing and treating a cancer by stage of disease. We illustrate the method using the example of melanoma. Methods. We designed a simple structured elicitation exercise for melanoma experts from the United Kingdom with the aim of describing the diagnosis, management, and SACT prescription for people with melanoma and the associated proportions offered each option. We modeled experts' beliefs using scaled beta distributions. We used random-effects meta-analysis to combine the estimates. Published unit costs (£; 2024-2025) were multiplied by estimated proportions to calculate the mean costs for the diagnosis, management, and SACT by disease stage. Results. Seven dermatologists, 5 oncologists, and 4 surgeons participated (2022-2023). There was variation in the estimates of the proportions receiving possible diagnosis, management, or SACT options. Diagnosing suspicious lesions cost £424 to £699 depending on the investigations required. Mean (95% confidence intervals) management costs were £782 (£611, £981) for stage 0, £946 (£776, £1,145) for stage 1a, £4,729 (£4,532, £4,944) for stage 1b/2, £3,719 (£3,213, £4,150) for macroscopic 3, and £2,827 (£2,757, £2,904) for microscopic 3. Mean SACT costs were £65,289 (£50,581, £74,521) for stage 3 and £134,065 (£115,787, £152,938) for stage 4. Conclusions. Our new approach to eliciting and combining estimates balances practical and theoretical considerations. We illustrate how this method produces estimates of the costs, and associated uncertainty, of the diagnosis, management, and SACT for melanoma by stage of disease in the absence of readily accessible diagnosis, management, and prescribing data. These cost estimates were not validated against registry data.