Cholesky Decomposition
A matrix factorisation technique decomposing a covariance matrix to generate correlated random samples from otherwise independently sampled parameters.
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.
Clinical Benefit
A favourable effect of an intervention on how a patient feels, functions or survives relative to an appropriate comparator.
Clinical Benefit Rate
A cancer outcome measure combining complete response, partial response, and stable disease rates, giving a broader benefit picture than response rate alone.
Cluster Analysis
A statistical technique grouping individuals into subsets, called clusters, so members within a cluster are more similar to each other than to outsiders.
Cohen's D
A standardised measure of effect size expressing the difference between two group means in units of their pooled standard deviation.
Cohort Model
A decision-analytic model simulating the average experience of a defined group of patients moving through health states, rather than tracking each individually.
Cohort Simulation
The process of running a Markov model by tracking the proportion of a hypothetical cohort in each health state over cycles, not individual patients.
Cohort Trace
The complete record of the proportion of a modelled cohort occupying each health state at every cycle, produced by a Markov cohort model.
Common Random Numbers
A variance reduction technique using the same sequence of random numbers across simulations of different alternatives, reducing the variance of their difference.
Communality
In factor analysis, the proportion of a variable's total variance explained by the underlying common factors, distinct from variance specific to it alone.
Comparator
The alternative intervention, treatment, or strategy against which a new option is evaluated in an economic evaluation.
Compartmental Model
A modelling approach dividing a population into distinct compartments, such as susceptible, infected, and recovered, and tracking flow between them over time.
Compensating Variation
A monetary measure of the change in wellbeing from a price or policy change, the sum needed after the change to restore original utility.
Competing Risks
A situation where a person is at risk of more than one type of event, so one event's occurrence prevents another from ever happening.
Condition Index
A diagnostic detecting problematic collinearity among predictor variables, calculated from the eigenvalues of the predictor matrix, larger values meaning worse collinearity.
Conditional Probability
The probability that an event will occur given that another specified event has already occurred, calculated from their joint probability.
Confidence Ellipse
A graphical region, typically on a cost-effectiveness plane, showing where the true joint value of incremental cost and effect is expected to fall.
Confidence Interval
A range of values, calculated from sample data, expected to contain the true population parameter with a specified level of confidence.
Confidence Interval Estimation
The statistical process of calculating a range of plausible values for an unknown parameter based on sample data and a specified confidence level.
Confirmatory Factor Analysis
A technique testing whether a hypothesised factor structure adequately explains observed correlations among measured variables, unlike exploratory factor analysis.