Dictionary

A

Abbreviated New Drug ApplicationConceptANDA, Abbreviated NDA

A streamlined US regulatory application letting a generic manufacturer gain approval by demonstrating bioequivalence to an approved reference drug, without repeating full trials.

Ablation EconomicsTermEconomics of Ablation, Ablation Cost-Effectiveness

The application of health economic evaluation to ablation procedures destroying targeted tissue, comparing procedural cost against long-term ongoing management or repeat interventions.

AbsenteeismConceptSickness Absence, Work Absence

Time lost from work due to illness, injury, or caregiving responsibilities, resulting in a direct, measurable cost to employers through lost productivity.

Absolute Effect MeasureTermAbsolute Difference, Arithmetic Effect Difference

A measure of effect expressed as the actual difference between two groups, such as absolute risk reduction, rather than as a ratio.

Absolute RiskConceptAbsolute Probability, AR

The probability that an individual in a defined population will experience a specific outcome over a given period, without reference to a comparison.

Absolute Risk ReductionConceptARR, Absolute Benefit Increase

Absolute risk reduction is the arithmetic difference in the probability of a specified adverse outcome between a comparator group and an intervention group over the same defined time horizon.

Absolute ShortfallConceptAbsolute QALY Shortfall, AS

Absolute shortfall is the future QALYs lost with a condition under current care versus the age- and sex-matched population, used by NICE to judge severity.

Absorbing StateConceptAbsorbing Health State, Absorbing Markov State

An absorbing state is a state in a Markov model that patients cannot leave once they enter it, usually death, so the whole cohort eventually ends there.

Academic DetailingConceptEducational Outreach, Educational Outreach Visit

Academic detailing is educational outreach in which trained clinicians visit prescribers to give independent, evidence-based advice about medicines.

Academic Expert in HTATermSubject-Matter Academic, Independent Academic Adviser

A researcher with specialised subject matter expertise invited to contribute independent scientific perspective to a health technology assessment process.

Academic HTA GroupTermAcademic Assessment Group, University HTA Team

An independent, university-affiliated team commissioned to critically evaluate submitted evidence within a formal assessment, distinct from manufacturer-submitted evidence.

Academic Medical CentreTermAcademic Health Centre, AMC

A hospital or health system affiliated with a medical school, combining patient care with education and research activities.

Accelerated ApprovalConceptFast-Track Approval, Conditional Marketing Authorisation

Accelerated approval is an FDA pathway that approves medicines for serious conditions on a surrogate endpoint, with confirmatory trials to verify benefit.

Accelerated Failure Time ModelConceptAFT Model, AFT Regression

An accelerated failure time (AFT) model is a survival model in which treatment or another factor stretches or shrinks time to an event by a time ratio.

Acceptability of HealthcareConceptPatient-Provider Fit, Cultural Fit

Acceptability is the dimension of access concerned with whether people find health services culturally, socially and personally appropriate enough to use.

Access AssessmentTermAccess Evaluation, Access Analysis

A structured evaluation of how readily a population can obtain needed healthcare, examining the dimensions that link population characteristics to actual service use.

Access BarrierConceptBarrier to Access, Barrier to Healthcare Access, Barrier to Health Care Access

An access barrier is any obstacle, such as cost, distance, waiting lists or discrimination, that prevents or delays a person obtaining needed healthcare.

Access NegotiationConceptPayer Negotiation, Price-and-Terms Negotiation

Access negotiation is the process in which a health technology supplier and a payer agree the price, eligibility and other conditions for patient access.

Access PolicyConceptHealthcare Access Policy, Health Care Access Policy

Access policy is the set of government or health system measures, such as coverage, user charges and waiting time rules, that shape access to healthcare.

Access to CareConceptHealthcare Access, Access to Healthcare

Access to care is the opportunity to obtain appropriate healthcare when needed, given the availability, location, cost and acceptability of services.

Accountability for ReasonablenessConceptA4R, Fair Priority-Setting Framework

Accountability for reasonableness (A4R) is a fair-process framework for health priority setting: publicity, relevance, revisability and enforcement.

Accountability StandardsTermResearch Governance, Ethical Conduct Requirements

The principles and requirements ensuring researchers and institutions can be held responsible for conducting studies ethically and in compliance with regulation.

Accountable CareTermPopulation Accountability, Shared-Responsibility Care

A delivery and payment model in which providers accept collective responsibility for cost and quality for a defined patient population.

Accountable Care ModelTermACO Model, Shared-Savings Model

A delivery model in which providers accept collective responsibility for cost and quality for a defined population, sharing savings or losses.

Accountable Care OrganizationConceptACO, Accountable Care Organisation

An accountable care organization (ACO) is a provider group that shares in savings if its patients' spending beats a benchmark and quality targets are met.

Acquired Treatment ResistanceConceptDeveloped Resistance, Post-Treatment Resistance

Acquired treatment resistance is the loss of a cancer treatment's effect after initial response or disease control, as the tumour adapts and progresses.

Acquisition CostConceptPurchase Cost, Invoice Cost

Acquisition cost is what a payer spends to buy a drug, at the price actually paid after any discounts, excluding administration and monitoring costs.

Active ChoiceConceptMandated Choice, Forced Choice

Active choice is a choice architecture design that asks people to state a decision, such as on organ donation or vaccination, instead of setting a default.

Active ComparatorConceptActive Control, Active Reference

An active comparator is an existing treatment, rather than placebo, that a new health technology is compared with in HTA and economic evaluation.

Active Control TrialConceptActive-Controlled Trial, Head-to-Head Trial

An active control trial is a randomised trial testing a new treatment against a known effective treatment, not placebo, for superiority or non-inferiority.

Active IngredientTermActive Pharmaceutical Ingredient, API

The specific component of a pharmaceutical product responsible for its intended therapeutic effect, unlike inactive ingredients included for stability or ease of use.

Active Life ExpectancyConceptALE, Healthy Active Years

Active life expectancy (ALE) is the average number of years a person of a given age can expect to live free of dependency in activities of daily living.

Active SurveillanceTermExpectant Monitoring, Structured Monitoring

A management strategy for slow-growing cancers, most notably some prostate cancer cases, involving close monitoring rather than immediate definitive treatment.

Active TreatmentTermInvestigational Treatment, Active Arm Treatment

The intervention under investigation in a trial intended to have a genuine pharmacological or therapeutic effect, unlike a placebo or inactive comparator.

Activities of Daily LivingConceptADL, Self-Care Tasks

Activities of daily living (ADL) are basic self-care tasks, such as bathing, dressing, toileting and eating, used to measure dependence and need for care.

Activity ImpairmentTermDaily-Task Impairment, Non-Work Impairment

A measure of how much a health condition interferes with an individual's ability to perform regular daily activities outside paid work.

Activity LimitationConceptActivity Restriction, Task Difficulty

Activity limitation is a difficulty a person has in carrying out a task or action, such as walking, washing or communicating, as defined in the WHO ICF.

Activity-Based BudgetingConceptABB, Activity-Driven Budget

Activity-based budgeting (ABB) builds a health service budget from forecast service volumes, the activities each needs and each activity's cost per unit.

Activity-Based CostingConceptABC, Activity Costing

Activity-based costing (ABC) is a method that assigns resource costs to activities, then to patients or services in proportion to the activities they use.

Activity-Based FundingConceptABF, Activity-Based Payment

Activity-based funding (ABF) pays hospitals a preset, case-mix-weighted price for each episode of care, so income follows patient numbers and complexity.

Actual CostTermRealised Cost, Realized Cost, Observed Cost, Incurred Cost

The real, measured expense incurred delivering a healthcare service, based on observed resource use and prices, unlike a standard or estimated cost.

Actuarial AnalysisConceptActuarial Assessment, Insurance Risk Analysis

Actuarial analysis uses probability and statistics to estimate expected health insurance claims for pricing premiums or contributions and holding reserves.

Actuarial ProjectionConceptActuarial Forecast, Claims Projection

Actuarial projection estimates future health spending, insurance claims or fund balances for a population from assumptions on demography, costs and policy.

Actuarial ValueConceptAV, Metal-Tier Coverage Level

Actuarial value (AV) is the share of the total allowed cost of covered care that a health plan is expected to pay for a standard population.

Acute Coronary SyndromeTermACS, Coronary Event

A spectrum of conditions from sudden reduced blood flow to the heart, covering unstable angina and myocardial infarction, requiring urgent treatment.

Adaptive Trial DesignConceptAdaptive Trial, Flexible Trial Design, Adaptive Study Design, Prospectively Adaptive Study, Flexible Study Design

Adaptive trial design is a trial plan whose prespecified rules let interim data change the trial, such as stopping early, while keeping inference valid.

Adaptive Value of InformationConceptAdaptive Value of Information, Sequential Value of Information

Adaptive value of information applies VOI analysis to staged research, re-valuing further data at each interim look to decide whether to continue.

Add-On TherapyTermAdd-On Treatment, Adjunctive Therapy

A treatment given in addition to existing baseline therapy, rather than replacing it, typically when the baseline alone gives inadequate control.

Added Therapeutic ValueConceptAdded Therapeutic Benefit, Added Benefit

Added therapeutic value is the extra patient-relevant benefit a new medicine gives over existing care, as graded by HTA bodies such as HAS and G-BA.

Added ValueTermIncremental Value, Net Added Benefit

The additional benefit a technology provides beyond existing standard care, a central consideration within health technology assessment and value-based frameworks.