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.
- K10ConceptKessler Psychological Distress Scale, K-10, Kessler 10
- K10 is the ten-item Kessler scale, a non-preference-based measure of psychological distress used in population surveys and mental health trials.
- 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.
- Kappa StatisticConceptCohen's Kappa
- The kappa statistic (Cohen's kappa) measures chance-corrected agreement between two raters on a categorical judgement, such as reviewers screening studies.
- Karnofsky Performance StatusConceptKPS, Karnofsky Score, Karnofsky Index, Karnofsky Scale, Karnofsky Performance Scale
- Karnofsky Performance Status is a clinician-rated 11-level score of a cancer patient's function, 100 normal and 0 dead, used to set treatment eligibility.
- Katz ADL IndexConceptKatz Index of Independence in Activities of Daily Living, Katz Index, Index of ADL, Katz ADL
- Katz ADL Index is a rating of independence in six basic activities of daily living, used to define dependency in trials and care models for older people.
- KCCQConceptKansas City Cardiomyopathy Questionnaire
- KCCQ is a 23-item heart failure questionnaire scoring symptoms, function, social limitation and quality of life 0 to 100, used as a trial and HTA outcome.
- 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.
- KIDSCREEN-10Concept
- KIDSCREEN-10 is a ten-item measure of health-related quality of life and wellbeing for ages 8 to 18, scored as a Rasch T-value against European norms.
- 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.
- Knowledge BrokeringConceptKnowledge Broker
- Knowledge brokering is work by people or organisations that link researchers with health decision makers so that research evidence is used in decisions.
- 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.