Dictionary

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Incremental Analysis MethodTermIncremental Approach, Marginal Comparison Method

An analytic approach comparing the additional cost and effect of one option relative to the next best alternative, rather than each option's total.

Incremental BudgetTermIncremental Budgeting, Roll-Forward Budget

A budget built by adjusting the previous period's budget slightly rather than starting each line item from zero.

Incremental CostConceptAdditional Cost, Marginal Cost Difference

Incremental cost is the difference in expected total cost between one healthcare option and its stated comparator, calculated using the same population, perspective, time horizon, currency, price year and costing methods.

Incremental Cost EstimationTermCost Difference Estimation, Incremental Costing

The process of estimating the difference in cost between two interventions, rather than each option's total cost in isolation.

Incremental Cost-Effectiveness Ratio (ICER)ConceptIncremental Cost per Unit, Cost-Effectiveness Ratio

The incremental cost-effectiveness ratio (ICER) is a treatment's extra cost divided by its extra health gain versus a comparator, such as cost per QALY.

Incremental Cost-Utility RatioConceptICUR

The incremental cost-utility ratio (ICUR) is the ICER of a cost-utility analysis: extra cost over a comparator divided by extra QALYs gained.

Incremental EffectivenessConceptAdditional Effectiveness, Incremental Health Gain

Incremental effectiveness is the difference in health outcomes between an intervention and its comparator, calculated in a consistent outcome unit and comparison direction.

Incremental InnovationTerm

An innovation making gradual, often modest improvements to an existing product or technology, unlike a radical or disruptive innovation.

Incremental Net BenefitConceptINB, Incremental Net-Benefit Statistic

The difference in expected net benefit between two competing interventions, found by converting the incremental health effect into money and subtracting incremental cost.

Incremental Net Monetary BenefitConceptINMB, Incremental Monetary Net Benefit

Incremental net monetary benefit (INMB) is the extra health of an option over its comparator, valued at a threshold, minus the extra cost, per patient.

Incubation PeriodTermIncubation Time, Exposure-to-Symptom Interval

The time interval between exposure to an infectious agent and the onset of symptomatic disease in an infected person.

IND ApplicationTermInvestigational New Drug Application, IND

An Investigational New Drug application requesting permission to begin human clinical trials, containing preclinical safety data and a proposed trial plan.

Independent AssessmentTermIndependent Evaluation, Arms-Length Assessment

An assessment conducted by an evaluator without a direct financial interest in the outcome, unlike one funded by the manufacturer.

Independent CensoringConceptNon-Informative Censoring, Random Censoring

An assumption that, within the information used for a survival analysis, censoring does not convey additional information about a person’s unobserved event time.

Independent Practice AssociationTermIPA, Independent Physician Association

An organisation of independent physicians contracting collectively with managed care organisations while maintaining their own separate practices.

Index InstrumentTerm

A health status questionnaire combining responses across dimensions into a single summary utility score, unlike a profile instrument reporting each dimension separately.

Index-Based MeasureTerm

A health outcome measure producing a single summary utility score by combining information across multiple dimensions, rather than reporting each separately.

IndicationTermApproved Use, Licensed Use

The specific medical condition or use for which a drug has received regulatory approval and is intended to be prescribed.

Indication-Based PricingTerm

A pricing approach in which a single drug is priced differently depending on the medical condition, or indication, for which it is used.

Indicator DevelopmentTermMetric Development, Measure Development

The process of designing and validating a specific, measurable metric intended to capture a dimension of healthcare quality or outcome.

Indirect BenefitTermSocietal Research Benefit, Non-Personal Benefit

A potential positive outcome resulting from a study that does not directly benefit the individual participant, such as knowledge helping future patients.

Indirect ComparisonConceptAnchored Comparison, Bucher Method

A method estimating the relative effect of two treatments never studied against each other directly, using their separate effects versus a shared comparator.

Indirect CostTerm

A cost associated with an intervention that is not directly incurred in providing it, such as lost productivity from illness or premature death.

Indirect ElicitationConcept

A health state valuation approach in which a descriptive questionnaire's responses are converted into a utility value using a pre-existing scoring algorithm.

Indirect EvidenceTermIndirect NMA Evidence, Chained Evidence

Within network meta-analysis, evidence comparing two treatments derived through a chain of comparisons via a common comparator, not from direct trials.

Indirect Treatment ComparisonConceptITC

Indirect treatment comparison (ITC) is the umbrella term for methods, such as NMA or MAIC, that compare treatments no trial has tested head to head.

Indirect Utility AssessmentConcept

The process of obtaining a health state utility value by applying a scoring algorithm from a prior valuation study to a respondent's questionnaire answers.

IndirectnessTerm

A GRADE evidence quality domain assessing whether the population, intervention, comparator, or outcome studied differs meaningfully from those relevant to the actual decision.

Individual Funding RequestTermIFR, Individual Patient Funding Request

A formal clinician application requesting funding for a patient's treatment outside standard coverage, demonstrating genuinely exceptional circumstances.

Individual MandateTerm

A legal requirement that individuals maintain a minimum level of insurance coverage or face a financial penalty, to prevent adverse selection.

Individual MarketTerm

The insurance market segment where coverage is purchased directly by individual consumers rather than through an employer or other group.

Individual Patient Data Meta-AnalysisConceptIPD Meta-Analysis, IPD-MA, Individual Participant Data Meta-Analysis, Participant-Level Meta-Analysis, Patient-Level Meta-Analysis, Individual Patient Meta-Analysis

Individual patient data meta-analysis systematically obtains, checks, and jointly synthesises participant-level records from eligible studies to estimate effects and investigate variation across studies or patients.

Individual Patient SimulationConceptIPS, Patient-Level Simulation, Individual-Level Simulation, Microsimulation, Patient-Level Microsimulation, Individual-Based Simulation, Individual Patient Modelling, Individual Patient Modeling

Individual patient simulation is a modelling approach that generates separate patient histories under specified rules and aggregates their costs and health outcomes for a target population.

Individual Sampling ModelTerm

A decision-analytic model generating results by repeatedly simulating individual patients, whose characteristics and pathways are drawn through random sampling from input distributions.

Individual-Level ModelTerm

A decision-analytic model tracking simulated patients one at a time rather than representing a population using aggregate cohort proportions.

Induced InnovationTermInsurance-Driven Innovation, Cost-Shielded Innovation

The theory that health insurance, by shielding patients from full costs, steers medical innovation toward more expensive, quality-enhancing treatments rather than cost-reducing ones.

Induction TherapyTermInduction Regimen, Initial Intensive Therapy

An initial, often intensive treatment given to rapidly reduce disease burden at the start of a course, typically followed by consolidation or maintenance.

Industry HTA LiaisonTerm

An individual within a manufacturer responsible for managing interactions with assessment bodies, coordinating evidence submission and query responses.

Industry RepresentativeTermManufacturer Representative, Industry Stakeholder

An individual employed by or contracted to a manufacturer who provides input or represents its perspective during an assessment process.

Inelastic DemandConceptPrice-Insensitive Demand, Unresponsive Demand

A condition in which quantity demanded changes proportionally less than a given price change, indicating consumers are relatively insensitive to price.

Inequality IndexTermInequality Measure, Distributional Index

A summary statistic that quantifies the extent of inequality in the distribution of income or health across a population, allowing comparison over time or between groups.

Infection Control EconomicsTermEconomics of Infection Control, IPC Economics

The application of health economic evaluation to preventing infection transmission in healthcare settings, covering hand hygiene, isolation, and environmental cleaning.

Infection MeasureTermInfection Indicator, HAI Measure

A quality indicator tracking the frequency of specific healthcare-associated infections, such as central line-associated bloodstream infections, within a facility.

Infection Prevention EconomicsTermEconomics of Infection Prevention, Preventive IPC Economics

The application of health economic evaluation to strategies preventing infections before they occur, spanning vaccination, hygiene promotion, and environmental interventions.

Infection RateTermInfection Frequency, Infection Occurrence Rate

A measure of how frequently a specific type of infection occurs within a defined population and time period.

Infectious Disease EconomicsTermEconomics of Infectious Disease, Communicable Disease Economics

The broad application of health economic evaluation to the prevention, diagnosis, and treatment of diseases caused by pathogenic microorganisms.

Infectious Disease EpidemiologyTermCommunicable Disease Epidemiology, ID Epidemiology

A branch of epidemiology studying the distribution, transmission dynamics, and control of communicable diseases within populations.

Inferential StatisticsTermStatistical Inference, Inferential Methods

A branch of statistics drawing conclusions about a broader population from sample data, incorporating formal methods for quantifying uncertainty.

Inflammatory Bowel DiseaseTermIBD, Crohn's and Colitis

A group of chronic conditions, mainly Crohn's disease and ulcerative colitis, involving digestive tract inflammation with a relapsing, remitting course.

Inflation AdjustmentTermPrice Rebasing, Real-Terms Adjustment

The process of restating cost data from different time periods in constant, comparable price terms, typically using a relevant price index.