Partitioned Survival Model
An oncology modelling technique estimating the proportion of a cohort in each health state using separately fitted survival curves for different endpoints, rather than modelling transitions.
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.
Permutation Test
A non-parametric hypothesis test determining significance by repeatedly rearranging observed data labels to build an empirical distribution under the null hypothesis.
Peto Test
A variant of the log-rank test using a specific weighting scheme offering statistical efficiency advantages under certain patterns of censoring.
Piecewise Model
A survival model dividing follow-up into distinct segments, each modelled with a separate, often simpler function, letting the hazard shape vary in steps.
Point Estimate
A single numerical value representing the best available estimate of an unknown parameter, unlike an interval estimate conveying its uncertainty range.
Population EVPI
The expected value of perfect information calculated for an entire affected patient population over time, rather than for a single patient.
Posterior Probability
The updated probability of a hypothesis after accounting for observed evidence, combining a prior probability with the likelihood of that evidence.
Predictive Accuracy
The degree to which a model's forecasts or classifications correspond to actual observed outcomes when tested against real data.
Prior Probability
The probability assigned to a hypothesis before accounting for new evidence, representing existing belief later updated through Bayesian analysis.
Probabilistic Analysis
An analysis in which uncertain inputs are represented by probability distributions rather than fixed values, and the model runs repeatedly with sampled values.
Probabilistic Sensitivity Analysis
A method characterising overall model uncertainty by assigning probability distributions to inputs and running the model repeatedly with randomly sampled values.
Probability
A numerical measure, ranging from zero to one, expressing the likelihood that a specific event will occur.
Probability-to-Rate Conversion
The mathematical transformation converting a probability of an event over a discrete time interval into its corresponding continuous-time hazard rate.
Product Limit Estimator
The formal statistical name for the Kaplan-Meier estimator, reflecting its calculation as a running product of conditional survival probabilities.
Proportional Hazards Assumption
The Cox model assumption that the hazard ratio between two groups stays constant over follow-up, even as the absolute hazard rate changes.
Pseudo-Random Number
A number generated by a deterministic algorithm that approximates the statistical properties of true randomness, used because genuine randomness is hard to compute.
Queuing Model
A mathematical model describing how entities wait in line for limited servers, used to analyse average waiting time and server utilisation.
Random Number Generation
The computational process of producing a sequence of numbers approximating true randomness, used to sample parameter values in probabilistic health economic models.
Rate-to-Probability Conversion
The mathematical transformation converting a continuous-time hazard rate into the probability of an event occurring within a discrete time interval.
Relative Survival
A survival measure comparing observed survival in a population to expected survival in a comparable general population, without needing cause-of-death data.