Quality of Evidence
Quality of evidence is a judgement, rated high to very low in GRADE, of how far a review, guideline or HTA can trust that an effect estimate is correct.
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.
Quality Score
A quality score is a single number summing checklist items to rate a study's methodological quality, now discouraged in favour of risk of bias judgements.
Quasi-Experimental Design
A quasi-experimental design estimates the causal effect of a health policy or treatment without randomisation, using a comparison group or period instead.
Random Effects Model
A random effects model is a meta-analysis model that lets true treatment effects differ between trials and estimates their mean and between-study variance.
Random Sampling
Random sampling selects members of a population by chance, giving each a known, non-zero probability of selection, so sample estimates can be generalised.
Randomised Controlled Trial
A randomised controlled trial (RCT) is a study that assigns people to an intervention or comparator by chance, HTA's preferred source of relative effects.
Randomization
Randomisation assigns participants to treatments by chance, balancing known and unknown prognostic factors on average so effects used in HTA are unbiased.
Real-World Data
Routinely collected information about patient health or healthcare delivery that may support research and decision making when fit for a defined purpose.
Real-World Evidence
Clinical evidence about a medical product's use, benefits, or risks derived from analysing real-world data, unlike evidence from a controlled trial.
Reference Standard
The reference standard is the best available method for deciding whether a target condition is present, against which a test's accuracy is judged.
Regression Analysis
Regression analysis is a set of statistical methods estimating how an outcome such as cost, QALYs or event risk varies with treatment and patient factors.
Relapse-Free Survival
Relapse-free survival (RFS) is the time from randomisation, or another stated start such as surgery, to relapse of the disease or death from any cause.
Relative Risk
Relative risk (RR) is the ratio of event risks in two groups over the same period, the treatment effect a decision model multiplies by a baseline risk.
Relative Risk Reduction
Relative risk reduction (RRR) is the percentage by which a treatment lowers the risk of an event compared with control, equal to one minus the risk ratio.
Reliability Assessment
An evaluation of the consistency and reproducibility of an instrument's results, covering internal consistency, inter-rater, and test-retest reliability.
ReQoL-10
ReQoL-10 is the 10-item Recovering Quality of Life questionnaire for mental health service users, scored as a total or as ReQoL-UI utilities for QALYs.
ReQoL-20
ReQoL-20 is the 20-item Recovering Quality of Life questionnaire for mental health service users, used at assessment and as a trial and research outcome.
Risk Ratio
The risk ratio (RR), or relative risk, is the risk of an event in one group divided by the risk in another over the same period, used in trials and HTA.
Robust Standard Error
An estimate of a regression coefficient's statistical uncertainty that remains valid even when standard modelling assumptions, such as constant error variance, are violated.
ROC Curve
The ROC (receiver operating characteristic) curve plots a test's sensitivity against its false positive rate at each cut-off, guiding thresholds in HTA.