Bias-Variance Tradeoff
The bias-variance tradeoff is how cutting systematic error (bias) tends to raise sampling variance, as in choosing HTA survival curves or subgroup inputs.
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.
Bibliographic Database
A bibliographic database is an indexed set of records describing published research, such as MEDLINE or Embase, searched to find studies for reviews.
Big Data
Big data is a term for very large, varied and fast-growing health datasets, such as linked records, claims and genomic data, that need specialised methods.
Binomial Distribution
The binomial distribution models how many of a fixed number of patients have an event when each has the same probability and outcomes are independent.
Biobank Data
Biobank data are stored biological samples and participant measurements linked to health records, used in health economics to estimate costs and outcomes.
Biomarker Endpoint
A biomarker endpoint is a trial outcome built on a measured biological marker, such as LDL cholesterol, which cost-utility models must convert into QALYs.
Blinding
Blinding (masking) keeps trial participants, clinicians, assessors or analysts unaware of assignment, limiting bias in effect, utility and cost estimates.
Block Randomization
Block randomisation assigns participants in small blocks with set numbers per arm in random order, keeping arms balanced throughout trials that inform HTA.
Body of Evidence
A body of evidence is all studies on one outcome of a guideline or HTA question, judged together; GRADE rates certainty as high, moderate, low or very low.
Bootstrap Standard Error
Bootstrap standard error is the standard deviation of an estimate, such as mean trial cost, recalculated across many resamples of the observed data.
Bootstrapping
Bootstrapping is a resampling method that estimates sampling uncertainty in trial costs, QALYs and net benefit from patient samples drawn with replacement.
Brier Score
The Brier score is the mean squared difference between predicted risks and observed binary outcomes, used to judge prediction models; lower is better.
Cancer Epidemiology
Cancer Epidemiology studies how often cancer occurs, what causes it and who survives or dies, supplying incidence and survival inputs to economic models.
Carryover Effect
Carryover Effect is a treatment's effect persisting into a later crossover trial period, which can bias effect estimates used in HTA and economic models.
Case Report
A case report details one patient's presentation, management and outcome; in HTA it can flag rare harms but not estimate their rate or a treatment effect.
Case Series Design
Case Series Design is an uncontrolled observational study of patients sharing a condition or treatment; in HTA it gives event rates, not treatment effects.
Case-Control Design
Case-Control Design is an observational study comparing past exposures of cases (with an outcome) and controls (without it), used in HTA for rare outcomes.
Categorical Data
Categorical data record which of a set of categories each observation falls in, such as alive or dead or an EQ-5D level, instead of a measured amount.
Causal Inference
Causal inference estimates what would happen to health outcomes or costs if a treatment or policy changed, using data, study design and stated assumptions.
Causal Pathway
A causal pathway is the sequence of steps through which an intervention or exposure produces a health outcome, acting through intermediate variables.