Pharmacoeconomic Evaluation Methods
Expert-defined terms from the Professional Certificate in Pharmacoeconomics in Health Care course at LearnUNI. Free to read, free to share, paired with a professional course.
Absolute Cost – The total monetary amount incurred for a health‑care inte… #
total cost, direct cost It includes drug acquisition, administration, monitoring, and adverse‑event management. Example: the absolute cost of a 12‑month biologic therapy may be $45,000. Practical use: serves as the base for incremental cost‑effectiveness ratios. Challenge: capturing all relevant cost components, especially indirect costs, can be difficult.
Adverse Event Cost – The incremental cost associated with managing side‑e… #
AE cost, toxicity cost This may comprise hospital stays, laboratory tests, and physician visits. Example: chemotherapy‑induced neutropenia may add $3,500 per episode. Practical application: incorporated into cost‑utility models to reflect real‑world resource use. Challenge: variability in event severity and treatment patterns across settings.
Aggregate Data – Summarized information pooled across individuals, such a… #
summary statistics, pooled data Used when patient‑level data are unavailable. Example: a meta‑analysis reports an average incremental cost of $2,000 for a new antihypertensive. Practical use: facilitates rapid health‑technology assessment. Challenge: loss of variability and inability to adjust for covariates.
Budget Impact Analysis (BIA) – An economic evaluation that estimates the… #
budgetary impact, financial projection It projects changes in expenditures over a defined time horizon. Example: a BIA might predict a $5 million increase in a regional health‑authority’s drug budget after introducing a novel anticoagulant. Practical application: informs formulary decisions and reimbursement negotiations. Challenge: requires accurate uptake forecasts and population estimates.
Cost‑Benefit Analysis (CBA) – A method that expresses both costs and bene… #
monetary valuation, net benefit Benefits may be valued using willingness‑to‑pay or productivity gains. Example: a vaccination program yields $10 million in avoided medical costs and $5 million in productivity gains, against $3 million in program costs, resulting in a net benefit of $12 million. Practical use: supports policy decisions where monetary thresholds are appropriate. Challenge: ethical concerns arise when placing a monetary value on health outcomes such as life years.
Cost‑Effectiveness Analysis (CEA) – An evaluation comparing the relative… #
incremental cost‑effectiveness ratio, ICER Outcomes may be life‑years saved, symptom‑free days, or cases averted. Example: a CEA finds that a new insulin formulation costs $8,000 per life‑year saved compared with standard insulin. Practical application: helps determine whether an intervention provides good value for money. Challenge: selecting appropriate outcome measures and handling uncertainty.
Cost‑Effectiveness Threshold – The maximum amount a decision‑maker is wil… #
WTP threshold, willingness‑to‑pay Thresholds vary by country (e.g., $50,000/QALY in the United States, £20,000–£30,000/QALY in the United Kingdom). Practical use: guides interpretation of ICERs. Challenge: thresholds may be arbitrary and not reflect actual budget constraints.
Cost‑Minimisation Analysis (CMA) – An economic evaluation used when inter… #
equivalence analysis, cost comparison Example: two generic antihypertensive drugs with identical blood‑pressure control are compared; the cheaper drug is preferred. Practical application: simplifies decision‑making when clinical outcomes are identical. Challenge: requires robust evidence of equivalence, which is often lacking.
Cost‑Utility Analysis (CUA) – A form of CEA that incorporates quality‑adj… #
QALY, utility‑based analysis Example: a CUA shows that a new oncology drug yields 0.8 additional QALYs at an incremental cost of $120,000, resulting in an ICER of $150,000/QALY. Practical use: widely accepted by health technology assessment agencies. Challenge: deriving reliable utility weights from patient populations.
Direct Cost – Expenses directly attributable to the provision of a health… #
medical cost, treatment cost Example: the direct cost of a surgical procedure includes operating‑room time, implants, and anesthesia. Practical application: forms the core of most pharmacoeconomic models. Challenge: distinguishing direct from indirect costs, especially in complex care pathways.
Discount Rate – The percentage used to convert future costs and benefits… #
present‑value factor, discounting Commonly applied rates are 3 % or 5 % per annum. Example: a cost incurred five years from now is multiplied by (1 + 0.03)^‑5 to obtain its present value. Practical use: ensures comparability of costs and outcomes occurring at different times. Challenge: choice of rate can substantially affect results, and guidelines differ across jurisdictions.
Economic Evaluation – The systematic comparative analysis of alternative… #
health‑economic analysis, value assessment Includes CBA, CEA, CUA, and CMA. Example: an economic evaluation may compare a new vaccine with existing immunisation schedules. Practical application: provides evidence for resource allocation decisions. Challenge: requires high‑quality data on both costs and outcomes.
Incremental Cost‑Effectiveness Ratio (ICER) – The ratio of the difference… #
cost‑effectiveness ratio, incremental ratio Formula: (Cost_A – Cost_B) / (Effect_A – Effect_B). Example: an ICER of $25,000 per QALY suggests the new drug provides additional health benefit at that cost. Practical application: central metric for decision‑makers. Challenge: interpretation is sensitive to uncertainty and threshold selection.
Incremental Net Benefit (INB) – An alternative to the ICER that expresses… #
net monetary benefit, NMB Positive INB indicates a cost‑effective intervention at the specified willingness‑to‑pay. Example: with a WTP of $50,000/QALY, an intervention with ΔEffect = 0.6 QALY and ΔCost = $20,000 yields INB = $10,000. Practical use: facilitates statistical testing of cost‑effectiveness. Challenge: requires a pre‑specified WTP threshold.
Indirect Cost – Costs that arise from loss of productivity, caregiver tim… #
productivity loss, societal cost Example: absenteeism due to chemotherapy side‑effects may cost an employer $1,200 per patient. Practical application: included in societal perspective analyses. Challenge: quantifying intangible costs and attributing them correctly.
Markov Model – A mathematical modeling technique that represents health s… #
state‑transition model, stochastic model Commonly used for chronic diseases where patients may move between states such as “stable,” “progressed,” and “dead.” Example: a Markov model for multiple sclerosis simulates yearly transitions among disability levels. Practical use: captures long‑term costs and outcomes. Challenge: requires accurate transition probabilities and may oversimplify complex pathways.
Monte Carlo Simulation – A probabilistic technique that repeatedly sample… #
probabilistic sensitivity analysis, PSA Generates cost‑effectiveness acceptability curves. Example: 10,000 iterations estimate the probability that a new drug is cost‑effective at a $30,000/QALY threshold. Practical application: informs decision‑makers about robustness of results. Challenge: computationally intensive and dependent on appropriate choice of distributions.
Net Monetary Benefit (NMB) – A reformulation of the ICER that expresses n… #
monetary benefit, benefit‑cost Positive NMB indicates cost‑effectiveness. Example: with a WTP of $100,000 per QALY, an intervention delivering 0.5 QALY at $30,000 yields NMB = $20,000. Practical use: simplifies statistical comparison across interventions. Challenge: interpretation hinges on the selected WTP.
Net Health Benefit (NHB) – The health equivalent of NMB, calculated as (E… #
health benefit, cost‑adjusted effect Example: an intervention with 1.2 QALYs and cost $40,000 at a WTP of $50,000 yields NHB = 0.8 QALYs. Practical application: provides a single health metric for ranking alternatives. Challenge: same dependence on WTP as NMB.
Probabilistic Sensitivity Analysis (PSA) – A method that assigns probabil… #
Monte Carlo, uncertainty analysis Results are presented as cost‑effectiveness planes or acceptability curves. Example: PSA shows a 70 % probability that a drug is cost‑effective at $25,000/QALY. Practical use: aids transparent decision‑making. Challenge: requires specification of appropriate distributions for each parameter.
Quality‑Adjusted Life Year (QALY) – A composite measure that combines len… #
utility‑adjusted survival, health‑adjusted life year Example: a patient lives 2 years with a utility of 0.7, resulting in 1.4 QALYs. Practical application: standard outcome in CUAs and health‑technology assessments. Challenge: utility measurement can be subjective and varies by instrument.
Reference Case – A set of methodological assumptions (perspective, discou… #
) recommended by health‑technology assessment bodies for consistency across analyses. standard scenario, methodological baseline Example: the NICE reference case uses a 3.5 % discount rate and a health‑service perspective. Practical use: ensures comparability of published studies. Challenge: may not reflect local practice or specific stakeholder preferences.
Societal Perspective – An analytical viewpoint that includes all costs an… #
population perspective, comprehensive viewpoint Example: a societal analysis of a vaccination program adds productivity gains from avoided illness. Practical application: aligns with many global health‑economics guidelines. Challenge: data collection is extensive, and some decision‑makers prioritize narrower perspectives.
Time Horizon – The period over which costs and outcomes are measured in a… #
analysis duration, study period Long time horizons capture all relevant downstream effects; short horizons may miss late benefits or costs. Example: a 20‑year horizon for a chronic disease therapy versus a 5‑year horizon for an acute intervention. Practical use: influences model complexity and data requirements. Challenge: projecting beyond available data introduces uncertainty.
Willingness‑to‑Pay (WTP) – The maximum amount a society or individual is… #
threshold value, monetary ceiling WTP thresholds guide interpretation of ICERs. Example: a health system may adopt a $45,000/QALY WTP threshold. Practical application: central to cost‑effectiveness decision rules. Challenge: thresholds are often debated and may not reflect actual budget constraints.
Adherence‑Adjusted Cost‑Effectiveness – An analysis that incorporates rea… #
compliance‑adjusted evaluation, adherence impact Example: lower adherence to an oral anticoagulant reduces its effectiveness, raising the ICER. Practical use: improves relevance of model outcomes to clinical practice. Challenge: adherence data are variable and may be difficult to obtain.
Budget‑Constrained Optimization – A decision‑making approach that seeks t… #
resource allocation, constrained maximization Often solved using linear programming techniques. Example: allocating limited funds among vaccines to achieve the greatest QALYs gained. Practical application: assists policymakers in prioritizing interventions. Challenge: requires accurate estimation of costs and health gains for each option.
Cost‑Effectiveness Plane – A graphical representation plotting incrementa… #
ICER plot, outcome space The northeast quadrant indicates higher cost and higher effectiveness; the southeast quadrant denotes lower cost and higher effectiveness (dominant). Example: a point in the southeast quadrant signifies a cost‑saving, more effective intervention. Practical use: visual tool for interpreting results. Challenge: interpretation can be ambiguous when points lie near the axes.
Decision Analytic Model – A structured framework (e #
g., decision tree, Markov model) that simulates the pathways, costs, and outcomes of health interventions. modeling framework, analytic structure Enables systematic comparison of alternatives. Example: a decision tree for acute myocardial infarction treatment pathways. Practical application: central to pharmacoeconomic evaluations. Challenge: model validity depends on quality of input data and assumptions.
Deterministic Sensitivity Analysis – A technique that varies one paramete… #
one‑way sensitivity, parameter testing Highlights key drivers of cost‑effectiveness. Example: varying drug price between $10,000 and $30,000 changes the ICER from $20,000/QALY to $60,000/QALY. Practical use: identifies parameters requiring robust data. Challenge: does not capture interactions between parameters.
Discounted Cost‑Effectiveness Ratio – An ICER calculated after applying d… #
present‑value ICER, discounted ratio Ensures that future costs and benefits are appropriately weighted. Example: a discounted ICER of $35,000/QALY may differ from an undiscounted value. Practical application: aligns with guidelines that mandate discounting. Challenge: selection of discount rates can be contentious.
Health Technology Assessment (HTA) – A multidisciplinary process that eva… #
technology appraisal, assessment process HTA bodies (e.g., NICE, CADTH) often rely on pharmacoeconomic evidence. Example: an HTA report recommends reimbursement for a new oncology drug based on CUA results. Practical use: informs policy, pricing, and coverage decisions. Challenge: balancing scientific rigor with timeliness and stakeholder interests.
Incremental Net Monetary Benefit (INMB) – The difference in NMB between t… #
incremental NMB, net benefit difference Positive INMB indicates the intervention is cost‑effective at the chosen WTP. Example: INMB of $5,000 at a $50,000/QALY threshold suggests favorable value. Practical application: facilitates statistical testing of cost‑effectiveness. Challenge: depends on accurate estimation of both costs and utilities.
Life‑Year Gained (LYG) – A measure of survival benefit that counts additi… #
survival gain, additional years Example: a new vaccine prevents premature death, yielding 0.3 LYG per vaccinated individual. Practical use: alternative outcome metric when quality‑adjusted measures are unavailable. Challenge: ignores morbidity and patient preferences.
Markov Cohort Model – A specific type of Markov model that follows a defi… #
cohort simulation, state‑based model Example: a cohort of diabetic patients progresses annually from “no complications” to “microvascular complications.” Practical application: efficient for large populations where individual heterogeneity is minimal. Challenge: may oversimplify patient‑level variability.
Micro‑Costing – A detailed costing approach that itemizes each resource u… #
bottom‑up costing, detailed costing Example: calculating the cost of a chemotherapy regimen by summing drug dose, infusion time, nursing hours, and consumables. Practical use: provides precise cost estimates for high‑technology interventions. Challenge: time‑consuming and requires granular data.
Monte Carlo Probabilistic Model – A model that incorporates randomness by… #
stochastic simulation, random sampling Generates a distribution of possible outcomes rather than a single point estimate. Example: estimating the probability that a new drug’s ICER falls below $30,000/QALY across 5,000 simulations. Practical application: informs risk‑adjusted decision‑making. Challenge: requires specification of joint distributions and may be computationally demanding.
Net Cost – The difference between total costs of an intervention and any… #
g., avoided hospitalizations). adjusted cost, residual cost Example: a drug costing $15,000 per patient may have $5,000 in avoided hospitalization costs, yielding a net cost of $10,000. Practical use: provides a more realistic estimate of financial impact. Challenge: accurate estimation of offset costs is often uncertain.
Opportunity Cost – The value of the best alternative foregone when resour… #
alternative cost, forgone benefit In health care, spending on a high‑cost drug may preclude funding for preventive services. Practical application: underscores the need for efficient resource allocation. Challenge: quantifying opportunity costs is inherently speculative.
Patient‑Reported Outcome Measures (PROMs) – Instruments that capture pati… #
self‑reported outcomes, health surveys PROMs inform utility estimation for QALY calculations. Example: the EQ‑5D questionnaire provides a utility score used in CUAs. Practical use: enhances relevance of economic evaluations to patient experience. Challenge: selection of appropriate PROMs and cultural adaptation.
Pharmacoeconomic Model Validation – The process of checking that a model… #
model verification, credibility assessment Validation may involve internal checks, external comparisons, and expert review. Example: comparing model‑predicted survival rates with registry data. Practical application: builds confidence in model outputs for decision‑makers. Challenge: limited availability of high‑quality external data.
Probabilistic Decision Tree – A decision‑analytic structure where branche… #
stochastic decision analysis, random branch Example: a tree evaluating different diagnostic pathways for a disease, each with probabilistic outcomes. Practical use: suitable for short‑term, discrete events. Challenge: complexity grows rapidly with many branches.
Quality‑Adjusted Life Day (QALD) – A finer resolution of the QALY, repres… #
daily utility, granular QALY Useful when modelling short‑term interventions. Example: a 30‑day treatment yielding a utility of 0.8 results in 24 QALDs (30 × 0.8). Practical application: improves precision in acute‑care models. Challenge: data on daily utilities are rarely collected.
Reference Case Sensitivity – Examination of how results change when key r… #
g., perspective, discount rate) are varied. scenario analysis, assumption testing Example: altering the discount rate from 3 % to 5 % shifts the ICER by 15 %. Practical use: assesses robustness of conclusions. Challenge: selection of alternative assumptions must be justified.
Scenario Analysis – Evaluation of model outcomes under alternative sets o… #
what‑if analysis, alternative scenario Example: a scenario where drug price is reduced by 20 % due to a negotiated discount. Practical application: informs negotiations and policy planning. Challenge: may produce numerous scenarios, complicating interpretation.
Sensitivity Threshold – The value of a parameter at which the cost‑effect… #
g., from cost‑effective to not). break‑point, critical value Example: a drug becomes cost‑effective only if its price falls below $12,000 per patient. Practical use: highlights price negotiation targets. Challenge: thresholds depend on model structure and other interacting variables.
Standardized Cost‑Effectiveness Ratio (SCER) – An ICER that has been adju… #
adjusted ICER, normalized ratio Example: converting an ICER from euros 2015 to US dollars 2022 using purchasing power parity and inflation indices. Practical application: enables meta‑analysis of economic evaluations. Challenge: accurate conversion requires reliable economic data.
Survival Analysis – Statistical methods (e #
g., Kaplan–Meier, Cox proportional hazards) used to estimate time‑to‑event outcomes, often feeding into economic models. time‑to‑event, hazard modeling Example: survival curves for a cancer drug inform transition probabilities in a Markov model. Practical use: provides realistic estimates of disease progression. Challenge: censoring and extrapolation beyond observed data can introduce bias.
Utility Weight – A numeric value between 0 (death) and 1 (perfect health)… #
preference score, health state value Derived from instruments like EQ‑5D, SG, or TTO. Example: a utility weight of 0.55 for moderate chronic pain. Practical application: core input for QALY calculations. Challenge: variability across populations and measurement methods.
Value of Information (VOI) Analysis – An approach that quantifies the ben… #
information gain, EVPI Expected Value of Perfect Information (EVPI) estimates the maximum worth of eliminating all uncertainty. Example: an EVPI of $2 million suggests further research could be justified. Practical use: guides research prioritization. Challenge: computationally intensive and relies on robust probabilistic models.
Willingness‑to‑Pay Curve – A graphical representation showing the probabi… #
acceptability curve, cost‑effectiveness probability Derived from PSA results. Example: at $30,000/QALY, the curve shows a 60 % probability of cost‑effectiveness. Practical application: aids stakeholders in interpreting uncertainty. Challenge: interpretation can be ambiguous when curves intersect.
Zero‑Cost Incremental Analysis – An evaluation where the incremental cost… #
cost‑neutral comparison, free‑difference Example: two formulations of the same drug with identical acquisition costs but differing adherence rates. Practical use: highlights non‑monetary benefits. Challenge: true zero cost is rare; hidden costs may exist.