Dictionary
The Dictionary provides concise definitions of health economics terms, arranged alphabetically for quick reference. Use it to understand unfamiliar terminology or confirm the meaning of a specific term.
K
- K-Fold Cross-ValidationConceptK-fold CV
- An internal validation procedure that repeatedly fits a model on all but one of K data folds and evaluates it on the held-out fold.
- Kaiser CriterionTermEigenvalue-Greater-Than-One Rule, K1 Rule
- A factor analysis rule retaining only factors with an eigenvalue greater than one, since these explain more variance than a single original variable.
- Kakwani IndexConceptKakwani Progressivity Index, Payment Progressivity Index
- A measure of the progressivity of a tax or financing system, calculated as the concentration index of payments minus the Gini coefficient of pre-tax income.
- Kaldor-Hicks EfficiencyTermKaldor-Hicks Criterion, Compensation Criterion
- A criterion for judging welfare improvement, satisfied when gainers from a change could in principle compensate losers and still be better off.
- Kalman FilterConceptState Estimator, Recursive State Filter
- A recursive estimator that predicts an evolving latent state and updates that estimate and its uncertainty when a new noisy measurement arrives.
- Kaplan-Meier CurveConceptKM Curve, Survival Step Function
- A graphical display of the Kaplan-Meier survival estimate, shown as a step function that decreases at each observed event over time.
- Kaplan-Meier EstimatorConceptKM Estimator, Kaplan-Meier Survival Estimate, Product Limit Estimator
- The Kaplan–Meier estimator calculates a non-parametric estimate of the survival function when follow-up can be right-censored.
- Kaplan-Meier MethodConceptKM Method, Product-Limit Method
- The overall approach of estimating and comparing survival functions using the Kaplan-Meier estimator, accounting for censored observations in time-to-event data.
- Kendall TauConceptKendall's Tau, Tau Coefficient
- A non-parametric measure of association between two ranked variables, based on the number of concordant and discordant pairs of observations.
- Key Secondary OutcomeTermKey Secondary Endpoint, Confirmatory Secondary Outcome
- A secondary trial endpoint important enough to warrant formal statistical testing with control for multiplicity, unlike a merely exploratory secondary endpoint.
- Kidney Transplant EconomicsTermRenal Transplant Economics, Economics of Kidney Transplantation
- The application of health economic evaluation to kidney transplantation, weighing procedure and lifelong immunosuppression costs against benefit relative to long-term dialysis.
- KnotTermSpline Breakpoint, Change Point
- A specified point along a variable's range at which a spline function is allowed to change shape, used in flexible parametric survival models.
- Knot PlacementTermKnot Selection, Spline Knot Positioning
- The methodological decision on where along the time axis to position a spline-based survival model's knots, whether by percentile or clinical judgement.
- Knowledge BarrierTermUnderstanding Gap, Comprehension Barrier
- An obstacle to healthcare arising from a lack of awareness or understanding, whether of available services or one's own condition.
- Knowledge TranslationTermKT, Knowledge Mobilisation
- The exchange, synthesis, and application of research knowledge to improve health outcomes, moving evidence from research into practice and policy.
- KurtosisConceptTailedness, Peakedness
- A measure describing a distribution's tail shape relative to a normal distribution, higher values indicating heavier tails and more extreme outliers.