PURPOSE: Decision makers commonly require cost-effectiveness analyses that account for the lifetime of the patient. Estimating survival outcomes that are clinically plausible presents several challenges, such as: extrapolation of long-term survival based on short-term clinical trial data; the requirement for indirect treatment comparisons (ITC) with alternative treatments where head-to-head trials are not available; patients switching treatments from the control arm to the active intervention. The workshop will discuss alternative methods to address these challenges in scenarios where standard methods are not sufficient. DESCRIPTION: It is often necessary to extrapolate survival outcomes beyond the observation period of the relevant clinical trials. This is typically achieved by fitting parametric survival models and obtaining expert clinical opinion to assess the plausibility of the extrapolations. The workshop will discuss new Bayesian methodologies in which clinical opinion or historical data on the expected survival at a specific timepoint is built into the estimation of long-term survival as prior information. Standard ITC methods for survival outcomes assume that included studies are similar in design and patient characteristics. ITCs of survival outcomes typically use hazard ratios as the input which requires the so-called proportional hazards assumption. The workshop will discuss alternative approaches applying relative treatment effects to multiple parameters of the survival distribution that may be utilized when these assumptions do not hold. Treatment switching methods such as rank preserving structural failure time models evaluate counterfactual survival times that would have been observed in the absence of switching. When evaluating the cost-effectiveness of a new first line treatment, in situations where the same treatment is already licensed as a second line treatment in medical practice, an alternative approach is presented that accounts for a given proportion of patients switching treatment, to better reflect clinical practice in certain jurisdictions.