Dictionary

N

N-of-1 TrialConceptN-of-One Trial, Single-Patient Trial

An N-of-1 trial is a randomised multiple crossover trial in one patient, comparing treatments over repeated periods to guide that patient's treatment.

Named Patient ProgrammeTermNPP, Named-Patient Supply

A pathway letting a physician request an unlicensed medicine for a specific, individually identified patient with unmet clinical need before formal approval.

Narrative ReviewConcept

A narrative review is a literature review that summarises research on a topic without a prespecified, reproducible search, selection and appraisal method.

Narrative SynthesisTermNarrative Data Synthesis, Textual Synthesis

An evidence synthesis summarising findings from multiple studies primarily through descriptive text, rather than formal statistical pooling.

Narrow NetworkTermLimited Network, Restricted-Panel Network

An insurance plan design including a limited number of contracted providers, offering less choice in exchange for typically lower premiums.

Nash EquilibriumConceptStrategic Equilibrium

A Nash equilibrium is a set of strategies, one per player, from which no player, such as a payer, provider or patient, gains by changing strategy alone.

National Health InsuranceTermNHI, Statutory Health Insurance

A financing model in which a single, government-administered programme covers an entire population, while care itself may still be delivered by mixed providers.

National Health ServiceTermNHS, Tax-Funded Health System

A health system financed primarily through general taxation and delivered through government-owned facilities and employed providers, exemplifying the Beveridge model.

National HTA AgencyTermNational HTA Body, HTA Agency

A government or government-mandated organisation conducting assessment to inform coverage, pricing, and reimbursement decisions within a country's health system.

National Immunisation ScheduleTermNIS, Routine Immunisation Schedule

The officially recommended sequence and timing of vaccinations for a country's population, developed by a national health authority based on disease burden.

National PerspectiveTermCountry-Level Perspective, National-Level Perspective

An analytic viewpoint considering costs and outcomes relevant to an entire country's health system, rather than a single institution, region, or payer.

National Schedule of Reference CostsTermNSRC, Reference Cost Schedule

The National Schedule of Reference Costs listed average unit costs of NHS services in England, renamed the National Schedule of NHS Costs from 2018/19.

NationalizationTermNationalisation, State Takeover

The transfer of ownership of an industry or set of assets, such as hospitals, from private to government control.

Natural History StructureTermNatural History Model, Disease Course Model

The representation within a model of how a disease progresses over time without intervention, including the timing of key clinical milestones.

Natural History StudyTermUntreated Disease Study, Disease Course Study

A study observing a disease's course over time without an experimental treatment, providing baseline information used as an external comparator, particularly for rare diseases.

Natural Language Processing HealthTermNLP in Health, Clinical Text Mining

An artificial intelligence category enabling computers to understand human language, applied to extracting clinically relevant information from unstructured medical text.

NCD Risk Factor PrevalenceTermNCD Risk Prevalence, Chronic Risk Factor Rate

A measure of the proportion of a population exhibiting a specific modifiable risk factor for noncommunicable disease, such as tobacco use.

NCPETermNational Centre for Pharmacoeconomics, Irish HTA Agency

The National Centre for Pharmacoeconomics, Ireland's body conducting pharmaceutical assessment to inform national reimbursement decisions.

NDA SubmissionTermNDA Filing, New Drug Application

A New Drug Application submitted to the US FDA seeking approval to market a new small-molecule drug, detailing safety, efficacy, and manufacturing.

Near MissTermClose Call, Averted Incident, Good Catch, Near-Miss Interception, Error Interception

An event with the potential to cause patient harm that did not actually result in injury, through intervention or chance.

Near Miss InvestigationTermClose-Call Investigation, Near-Miss Analysis

An inquiry following an event that could have caused harm but did not, intended to address system vulnerabilities before actual harm occurs.

Near Miss RateConceptClose-Call Rate, Near-Miss Frequency

A near miss rate is a patient safety indicator counting incidents stopped before they reach a patient per unit of care, such as per 1,000 medication doses.

Near Miss ReportingTermClose-Call Reporting, Near-Miss Notification

The systematic documentation of events with potential to cause harm that did not result in injury, revealing system vulnerabilities early.

Negative BinomialConceptNB Distribution, Overdispersed Count Model

A discrete probability distribution modelling count data with more variability than a Poisson distribution would predict, known as overdispersion.

Negative Binomial RegressionConceptNB Regression, Overdispersed Count Regression

Negative binomial regression models counts of health care use, such as admissions or exacerbations, whose variance is larger than a Poisson model allows.

Negative ExternalityConceptExternal Cost, Negative Spillover

A negative externality is an uncompensated cost, such as second-hand smoke or antibiotic resistance, that an activity imposes on third parties.

Negative FeedbackTermBalancing Loop, Self-Correcting Loop

A causal relationship in which a change in one variable triggers effects that counteract or dampen the original change, stabilising the system.

Negative Likelihood RatioConceptLR-, Negative LR

Negative Likelihood Ratio (LR-): (1 minus sensitivity) over specificity, the factor by which a negative test multiplies disease odds in decision models.

Negative ListTermDelisted Formulary, Non-Reimbursed List

A list of medications or services explicitly excluded from reimbursement coverage, unlike a positive list specifying what is covered.

Negative Predictive ValueConceptNPV Diagnostic, True-Negative Share

Negative predictive value (NPV) is the share of people with a negative test result who truly lack the condition, which models use to count missed cases.

Negative RecommendationTermDo-Not-Reimburse Recommendation, Rejection, Exclusion, Non-Recommendation, Negative Coverage Decision

A body's formal decision not to recommend a technology for funding, based on unacceptable cost-effectiveness at the reviewed price.

Negative StudyConceptNegative Trial, Null Result

A negative study is one whose main result shows no statistically significant or clinically important effect, which is not proof that no effect exists.

Neglected Disease EconomicsTermNTD Economics, Neglected Tropical Disease Economics

The application of health economic evaluation to diseases disproportionately affecting low-income populations with historically limited research and development investment.

Negotiated PricingTermPrice Negotiation Outcome, Negotiated Drug Price

A treatment price established through direct discussion between a manufacturer and payer, unlike a price set unilaterally or by government formula.

Negotiated RateTermIn-Network Rate, Negotiated Provider Rate

A payment amount established through direct negotiation between provider and payer, unlike a rate set unilaterally through a fee schedule.

Nelder-Mead MethodConceptDownhill Simplex Method, Amoeba Method

The Nelder-Mead method is a derivative-free algorithm that moves a simplex of trial points to minimise a score, used to calibrate health economic models.

Nelson-Aalen EstimatorConceptNelson-Aalen, Cumulative Hazard Estimator

A non-parametric method for estimating the cumulative hazard function from censored data, closely related to the Kaplan-Meier estimator.

Neoadjuvant TherapyTermNeoadjuvant Treatment, Pre-Surgical Therapy

Treatment given before a primary treatment, most commonly surgery, intended to shrink a tumour and make subsequent treatment more effective or less extensive.

Nephrology EconomicsTermRenal Economics, Kidney Care Economics, Renal Disease Economics, Dialysis Economics, Dialysis Cost-Effectiveness, Renal Replacement Economics

The broad application of health economic evaluation to kidney-related conditions, spanning chronic kidney disease, dialysis, and kidney transplantation.

NephrotoxicityTermRenal Toxicity, Kidney Toxicity

An adverse effect in which a drug or treatment damages the kidneys, potentially impairing their normal filtering function.

Nested LoopTermTwo-Level Simulation, Nested Monte Carlo

A simulation structure in which one inner simulation runs repeatedly within each iteration of an outer simulation, used to separate sources of uncertainty.

Net BenefitConceptNB

Net benefit places health gains and costs on one scale by valuing health at a cost-effectiveness threshold, or directly in money, and subtracting costs.

Net Benefit ApproachConceptNB Framework

The net benefit approach is a cost-effectiveness decision framework that ranks options by net benefit at a stated threshold instead of by ratios.

Net Budget ImpactTermNet BIA Result, Incremental Budget Impact

The overall change in spending from adopting a new technology, after accounting for offsetting savings elsewhere, such as avoided hospital admissions.

Net Health BenefitConceptNHB, Incremental Health Benefit

Net health benefit (NHB) is the health an option gains, in QALYs, minus the QALYs its extra cost would buy elsewhere at the cost-effectiveness threshold.

Net MarginTermNet Profit Ratio, Bottom-Line Margin

A financial ratio calculated as net income divided by total revenue, showing the proportion of revenue remaining as profit.

Net Monetary BenefitConceptNMB, Money-Valued Benefit

Net monetary benefit (NMB) is an option's health outcome valued in money at a cost-effectiveness threshold minus its cost, used to rank healthcare options.

Net Present ValueConceptNPV, Discounted Net Value

Net present value is the sum of monetary net flows at different times after each has been discounted to a common valuation date, including the initial flow.

Net PriceTermPost-Rebate Price, Discounted Transaction Price

The actual price a manufacturer realises for a treatment after all rebates and discounts, distinct from its publicly listed gross price.

Net Promoter ScoreTermNPS, Patient Recommendation Score

A customer loyalty metric based on likelihood to recommend, adapted in healthcare to measure patient satisfaction and provider recommendation likelihood.