Parametric Survival
Survival estimates derived from a fitted mathematical distribution rather than directly from observed data alone, allowing extrapolation beyond the data.
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.
Concepts, entries and ontology terms
A concept page is a published entry on the wiki. Some concepts also have a full encyclopaedia article. The Health Economics Ontology (HEO) holds every concept, including dictionary terms without an article, so it is larger than the list of published pages. The knowledge graph shows how concepts relate to each other.
Parametric Survival Model
A parametric survival model specifies a probability distribution for time to a defined event, enabling estimation of survival and hazard functions and projection beyond observed follow-up under stated assumptions.
Pareto Efficiency
Pareto efficiency, or Pareto optimality, is a state where resources such as a health budget cannot be reallocated to help anyone without harming someone.
Pareto Frontier
The set of feasible options that are not dominated by another option that is at least as good on every specified objective and strictly better on at least one.
Pareto Improvement
A Pareto improvement is a change, such as a reallocation of a health budget, that makes at least one person better off and nobody worse off.
Partial Correlation
Partial correlation is the correlation between two variables, such as costs and QALYs, after the linear effects of other variables are removed from both.
Partial Economic Evaluation
A partial economic evaluation studies costs alone, outcomes alone, or one option's costs and outcomes without a comparator, so cannot show value for money.
Particle Filter
A sequential Monte Carlo algorithm that approximates the evolving probability distribution of a hidden state with weighted simulated particles, updating their weights as observations arrive.
Particle Swarm Optimisation
Particle swarm optimisation (PSO) is a search method that moves candidate solutions towards the best ones found, used to calibrate health economic models.
Partitioned Survival Model
A partitioned survival model is a cancer economic model that uses PFS and OS curves to split a cohort into progression-free, progressed and dead states.
Patient Time Cost
Patient time cost is the value of the hours patients spend travelling to, waiting for and receiving health care, often valued at a wage rate.
Pattern Mixture Model
A pattern mixture model fits a separate model for each missing data pattern, so trial dropouts can differ from completers in health economic evaluation.
Pearson Correlation
Pearson correlation is a -1 to +1 measure of linear association, the covariance over the product of standard deviations, as between costs and QALYs.
Pecuniary Externality
A pecuniary externality is an externality that works through prices, as when NHS demand raises agency rates other buyers pay, shifting money to sellers.
Permutation Test
A permutation test is a hypothesis test that reshuffles treatment labels between trial patients to see how often a cost or outcome gap this large arises.
Perspective
Perspective in health economic evaluation is the viewpoint, such as the health system, payer or society, that decides which costs and outcomes are counted.
Peto Test
The Peto test is a weighted log-rank test comparing survival between groups, weighting each event time by pooled survival so earlier events count more.
Pharmacokinetics
Pharmacokinetics is the study of how the body absorbs, distributes, metabolises and excretes a drug over time, which sets the dose and dosing interval.
Piecewise Model
A piecewise model is a survival model used in economic evaluation that splits follow-up at cut points and fits a separate hazard within each interval.
Point Estimate
A point estimate is a single value calculated from data, such as a mean cost or hazard ratio, offered as the best estimate of an unknown parameter.