Census Data
Census data are counts and characteristics of a whole population from periodic official enumeration, used in health economics for denominators and models.
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.
Central Limit Theorem
The central limit theorem states that the mean of many independent observations with finite variance is approximately normal, whatever their distribution.
Certainty of Evidence
Certainty of evidence is GRADE's rating, from high to very low, of confidence that a true effect falls on one side of a threshold or within a chosen range.
Chi-Square Distribution
The chi-square distribution describes a sum of squared independent standard normals and is the reference for likelihood ratio, heterogeneity and fit tests.
Claims Data
Claims data are records providers submit to insurers or public payers to be paid, reused in health economics to measure resource use, costs and outcomes.
Classification Accuracy
Classification accuracy is the proportion of cases a test, coder or prediction rule assigns to the correct category, judged against a reference standard.
Classification Methods
Classification methods are statistical and machine learning techniques that assign patients or other cases to predefined classes, such as risk groups.
Clinical Endpoint
A clinical endpoint is a predefined trial outcome for judging a treatment; strictly, one directly measuring how a patient feels, functions or survives.
Clinical Epidemiology
Clinical epidemiology applies epidemiology to patients, measuring test accuracy, prognosis and treatment effects for clinical and economic decisions.
Clinical Evidence
Clinical evidence is data from trials and observational studies on an intervention's benefits and harms, used in HTA and economic evaluation.
Clinical Meaningfulness
Clinical meaningfulness is whether a treatment effect is large enough to matter to patients and change their care, not just statistically significant.
Clinical Outcome Assessment
A clinical outcome assessment (COA) measures how a patient feels or functions, through patient, clinician or observer reports or a standardised task.
Clinical Trial
A clinical trial is a study that prospectively assigns people to health interventions to measure their effects, giving evidence for regulators and HTA.
Clinician-Reported Outcome
A clinician-reported outcome (ClinRO) is a clinical outcome assessment in which a trained health professional rates the patient using clinical judgement.
Cluster Analysis
Cluster analysis is an unsupervised method that sorts patients, providers or countries into groups whose members are more alike than those in other groups.
Cluster Effect
A cluster effect is the tendency of patients in the same practice or hospital to have similar outcomes and costs, so their data are not independent.
Cluster Randomization
Cluster randomization allocates groups, such as hospitals or GP practices, to trial arms, so clinical and economic analyses must allow for clustering.
Co-Primary Outcome
A co-primary outcome is one of two or more primary outcomes in a trial, each of which must show a significant treatment effect for the trial to succeed.
Cohen's d
Cohen's d is a standardised effect size: the difference between two group means divided by their pooled standard deviation, used to compare studies.
Cohort Design
A cohort design is an observational study that follows people grouped by exposure or treatment forward from a common start to compare later outcomes.