Martingale Residual
A residual used to diagnose the fit of a Cox model, checking the functional form of continuous covariates and identifying influential observations.
Encyclopaedia
Explore comprehensive, evidence-informed explanations of key health economics concepts, including their development, application and relationships to other concepts. Published entries are validated through human expert review.
Memorylessness
The defining property of a Markov process that future transition probabilities depend only on the present state, with no influence from the path taken.
Metropolis-Hastings
A Markov chain Monte Carlo algorithm generating samples by proposing candidate values and accepting or rejecting them by a rule ensuring convergence.
Microsimulation
A simulation technique modelling individual entities separately through time based on their own characteristics and randomly sampled events, with results emerging from the total.
Mixture Cure Model
A cure model treating the population as a mixture of a cured fraction facing only background mortality and an uncured fraction remaining at risk.
Mixture Model
A statistical model representing a population as a combination of two or more distinct subgroups, each following its own underlying distribution.
Model Averaging
A statistical technique combining predictions from several plausible candidate models, weighted by their relative statistical support, rather than relying on one selected model.
Model Diagnostics
A set of statistical and technical checks assessing a model's performance, such as poor calibration or unstable results under minor input changes.
Model Fit
The degree to which a statistical or structural model's predictions correspond to observed data, used to judge whether a specification is adequate.
Model Selection
The process of choosing among alternative model structures or specifications for an evaluation, guided by fit, clinical plausibility, and parsimony.
Model Validation
The overall process of establishing confidence that a model's structure and results adequately represent the real-world system it is meant to capture.
Monte Carlo Error
The statistical imprecision in a simulation estimate from using a finite number of iterations, distinct from the underlying parameter uncertainty being characterised.
Monte Carlo Integration
A numerical technique estimating a complex integral's value by sampling random points repeatedly and averaging them, useful when no closed-form solution exists.
Monte Carlo Simulation
A technique estimating a model's output under uncertainty by repeatedly sampling random values for its inputs from specified distributions across many iterations.
Morris Method
A global sensitivity analysis technique efficiently screening many input parameters for negligible, linear, or interactive effects, using relatively few model runs.
Multi-Objective Optimisation
An optimisation approach used when a decision involves competing objectives, such as maximising benefit while minimising cost, producing a set of trade-off solutions.
Multivariate Sampling
The simultaneous drawing of random values for multiple correlated input parameters from their joint probability distribution, rather than sampling each independently.
Nelder-Mead Method
A numerical optimisation algorithm searching for a function's minimum using a moving shape, called a simplex, without needing the function's derivative.
Nelson-Aalen Estimator
A non-parametric method for estimating the cumulative hazard function from censored data, closely related to the Kaplan-Meier estimator.
Net Survival Model
A survival model estimating the survival a population would experience if the disease studied were the only possible cause of death.