Dictionary

R

RAC AuditTermRecovery Audit Contractor, Recovery Auditor

A review under the US Medicare Recovery Audit Contractor programme, using contractors paid by a share of recovered improper payments.

Radiation TherapyTermRadiotherapy, Radiation Treatment

A cancer treatment using high-energy radiation to damage and destroy cancer cells, delivered externally or via radioactive material placed near the tumour.

Radical InnovationTermBreakthrough Innovation, Disruptive Breakthrough, Step Change, Discontinuous Improvement, Breakthrough

An innovation introducing a fundamentally new approach or capability, a significant departure from existing solutions rather than an incremental improvement.

Radiological ResponseTermImaging Response, Radiographic Response

A treatment response measure based on imaging assessment of tumour size, classified into categories such as complete response, partial response, or progressive disease.

Radiology Information SystemTermRIS, Imaging Workflow System

A specialist software system managing radiology department workflows, from imaging order entry through result reporting, integrated with imaging archives.

RAND Health Insurance ExperimentTermRAND HIE, Health Insurance Experiment

A large randomised US experiment assigning families to insurance plans with varying cost-sharing levels, providing key evidence on how price affects healthcare use.

Random Effects ModelConceptREM, Exchangeable-Effects Model, Random Effects, Random Effects Synthesis

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 ErrorTermStochastic Error, Irreducible Noise

Variation in results attributable to chance alone, from the statistical variability of sampling, unlike systematic error, which reflects a consistent directional bias.

Random Number GenerationConceptRNG, Random Draw Generation

Random number generation supplies the uncertain draws used in probabilistic sensitivity analysis, microsimulation, discrete-event simulation, bootstrap procedures, and other stochastic analyses.

Random Parameter ModelConceptRandom Coefficient Model, Heterogeneous-Parameter Model

A random parameter model, or mixed logit, is a discrete choice model in which preference weights vary across people, estimated as a mean and a spread.

Random SamplingConceptProbability 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.

Random SearchTermStochastic Search, Randomised Sampling Search

An optimisation technique evaluating an objective function at randomly sampled points in the parameter space rather than a systematic grid.

Randomised Controlled TrialConceptRCT, Randomised 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.

RandomizationConceptRandom Allocation, Randomisation

Randomisation assigns participants to treatments by chance, balancing known and unknown prognostic factors on average so effects used in HTA are unbiased.

RangeTermData Spread, Min-Max Span

A dispersion measure calculated as the difference between the maximum and minimum values in a dataset, sensitive to extreme outliers.

Ranking MethodTermRank Ordering Method, Ordinal Ranking

A health state valuation technique in which respondents order health states from most to least preferred, without indicating the size of preference differences.

Rapid AssessmentTermRapid HTA, Abbreviated Assessment

An abbreviated assessment conducted under significant time constraints, streamlining methodological steps to produce timely evidence for an urgent decision.

Rapid Cycle ImprovementTermRCI, Rapid-Cycle QI

An approach emphasising testing small, incremental changes quickly through successive plan-do-study-act cycles, allowing rapid learning and adjustment.

Rapid ReviewTermStreamlined Review, Accelerated Evidence Review

An abbreviated systematic review conducted under time constraints, streamlining literature searching or quality assessment to produce timely evidence.

Rapid Review HTATermRapid HTA Review, Fast-Track HTA Review

An abbreviated systematic review conducted under time constraints, streamlining steps such as searching or quality assessment to support an urgent decision.

Rapid UpdateTermFast Guidance Refresh, Expedited Update

An expedited revision to previously published guidance, incorporating important new evidence more quickly than a standard review cycle allows.

Rare Disease EconomicsTermRare Condition Economics, Economics of Rare Diseases

The application of health economic evaluation to conditions affecting a small population share, adapting standard methods for limited natural history data and small trials.

Rate AdjustmentTermRate Correction, Adjusted Rate Method

A modification to an existing payment rate, up or down, implemented to reflect changes in costs or policy priorities.

Rate BandTermRating Tier, Premium Band

A regulatory range within which an insurer may vary premiums by a specific rating factor, such as age, limiting maximum variation.

Rate DifferenceTermExcess Rate, Additive Rate Contrast

The absolute difference between the incidence rates in two groups, giving a direct measure of the excess rate of disease from an exposure.

Rate ReviewTermInsurer Rate Filing, Premium Filing Review

A regulatory process examining a proposed premium increase for reasonableness before an insurer is permitted to implement it.

Rate SettingTermReimbursement Price Determination, Payment Level Setting

The overall process by which an insurer or regulator determines premium or payment rates for a health insurance product or contract.

Rate-to-Probability ConversionConceptRate-Probability Transformation, Rate-Based Probability Estimation, Hazard-to-Probability Conversion, Hazard Transformation, Rate-Probability Transform

Rate-to-probability conversion turns an event rate, such as deaths per person-year, into the probability of the event within one cycle of a Markov model.

Rating MethodTermRating Scale Valuation, Category Rating Technique

A health state valuation technique in which respondents assign a numerical score to a health state on a defined scale, such as a visual analogue scale.

Ratio ScaleConceptRatio Level of Measurement, Ratio-Level Scale, Ratio Variable

Ratio scale is a level of measurement with equal intervals and a true zero, such as cost or survival time, so a claim of twice the cost is meaningful.

Ratio ScalingTermRatio Measurement, Constant-Sum Scaling

A measurement approach in which respondents express one stimulus's magnitude relative to another as a numerical ratio, such as twice as severe.

Rational ChoiceTermRational Agent Model, Utility Maximisation Assumption

A model of decision-making in which individuals are assumed to select the option that maximises their expected utility given preferences and information.

RationingTermCare Limitation, Scarce-Resource Allocation

The deliberate limiting of access to healthcare due to resource scarcity, occurring in some form within every health system.

Rationing ApproachTermCare-Limitation Strategy, Allocation Approach

The specific method a health system uses to allocate limited resources among competing needs, explicit and transparent or more implicit.

Rawlsian JusticeTermJustice as Fairness, Difference Principle

A theory of distributive justice holding that inequalities are justified only if they benefit the least advantaged, derived from a hypothetical veil of ignorance.

Rawlsian WelfareTermMaximin Welfare, Rawlsian Objective

A conception of social welfare judging policies by their effect on the least advantaged, rather than the total or average welfare produced.

ReadmissionConceptRehospitalisation, Return Admission

A readmission is a further hospital admission soon after discharge, often within 30 days, used to judge inpatient care quality and counted as a cost.

Readmission ManagementTermRehospitalisation Reduction, Return-Admission Control

The strategies used to identify patients at high risk of hospital readmission and implement targeted interventions to prevent avoidable returns.

Readmission RateTermRehospitalisation Rate, 30-Day Return Ratio, Readmission Measure

A measure of the proportion of patients readmitted to hospital within a defined period, commonly thirty days, after a prior discharge.

Real CostTermInflation-Adjusted Cost, Constant-Price Cost

A cost expressed in constant prices after removing the effect of inflation, allowing valid comparison across different time periods.

Real Option ValueConceptOption Value of Waiting, Real Options Analysis

Real option value is the extra health gain a treatment creates by keeping patients alive and eligible long enough to benefit from future innovations.

Real-World DataConceptRWD, Routine-Practice 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 EvidenceConceptRWE, Routine-Practice Evidence, RWE in HTA, Routine-Data HTA Evidence

Clinical evidence about a medical product's use, benefits, or risks derived from analysing real-world data, unlike evidence from a controlled trial.

Real-World ValueTermRoutine-Practice Value, Observed Value in Practice

An assessment of a technology's actual benefit and cost-effectiveness observed under routine clinical practice, unlike trial-based efficacy value estimates.

RebateTermManufacturer Discount, Volume Concession

A retrospective payment from a manufacturer to a payer, typically a percentage of price or based on utilisation volume, reducing true net cost.

Rebate AgreementTermDiscount Agreement, Refund Contract

A formal contract establishing the terms under which a rebate will be paid, including the percentage and any formulary or utilisation conditions.

Recall BiasTermMemory Bias, Retrospective Recall Error

A form of information bias where participants with a particular outcome recall past exposures differently, often more thoroughly, than those without it.

Recall Period SelectionTermRecall Window Choice, Recall Timeframe Selection

The methodological decision on how far back respondents are asked to consider when reporting symptoms on a health status questionnaire.

Recombinant ProteinTermrProtein, Engineered Protein Drug

A protein produced through genetic engineering by inserting its coding gene into a host organism, such as bacteria or yeast, for therapeutic manufacture.

RecommendationTermAdvisory Guidance, Recommended Action

The formal conclusion issued by an assessment body specifying whether and under what conditions a technology should be adopted.