Credible Interval Estimation
The Bayesian process of calculating a range of plausible values for a parameter based on its estimated posterior probability distribution.
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.
Criterion Validity
The degree to which an instrument's scores correlate with an accepted external reference measure, either concurrently or in predicting a future outcome.
Critical Value
The specific threshold of a test statistic separating the region where a null hypothesis is rejected from where it is not.
Cross-Price Elasticity
A measure of how the quantity demanded of one good responds to a price change in a different good, such as a substitute or complement.
Cross-Sectional Design
An observational design measuring exposure and outcome simultaneously in a population at a single point in time, rather than over time.
Cross-Validation
A statistical technique assessing how well a model generalises to independent data, typically by repeatedly splitting data into fitting and testing subsets.
Crossover Design
A trial design in which each participant receives more than one treatment being compared, typically in random sequence separated by a washout period.
Crossover Trial
A trial in which participants sequentially receive two or more treatments under comparison, with each participant's response compared against their own.
Crosswalk
A statistical mapping converting health state scores from one version of an instrument to an equivalent score on another version.
Cubic Spline
A piecewise polynomial interpolation method that fits smooth cubic curves between data points while maintaining continuity of the function and its derivatives.
Cumulative Hazard
The total accumulated risk of an event by a given point in time, found by integrating the instantaneous hazard rate up to that point.
Cumulative Incidence
The proportion of an initially disease-free population that develops a specific outcome over a defined follow-up period, a measure of average risk.
Cure Fraction
The proportion of a population modelled as having no residual risk of the disease-specific event after successful treatment, effectively behaving as cured.
Cure Fraction Model
A survival model separating a population into a cured subgroup facing only background mortality and an uncured subgroup remaining at risk of the disease event.
Cure Model
A survival model assuming a defined proportion of a population will never experience the event of interest, distinguishing this cured group from those still at risk.
Cure Rate Model
A statistical model estimating both the proportion of a population considered cured and the survival distribution governing the remaining uncured population.
Current Ratio
A financial ratio calculated as current assets divided by current liabilities, used to assess an organisation's ability to meet short-term obligations.
Curve Fitting
The statistical process of identifying the mathematical function that best represents an observed pattern of data, such as observed survival times.
Cycle
A discrete unit of time in a Markov model during which patients may transition between health states, dividing the whole time horizon.
Cycle Length
The duration of time represented by a single cycle within a Markov model, chosen based on the clinical context being modelled.