Signature
DOM = (Delta_C <= 0) and (Delta_E >= 0) and (Delta_C < 0 or Delta_E > 0)
| Inputs | Definition | Unit |
|---|---|---|
Delta_C | Expected cost of the intervention minus that of the comparator | currency per defined population or person |
Delta_E | Expected health effect of the intervention minus that of the comparator | health-outcome unit per defined population or person, for example QALYs |
DOM | Equals 1 (true) when the intervention dominates the comparator and 0 (false) otherwise | binary indicator |
|---|
Function
Dominance classification function
Maps the expected costs and expected health effects of mutually exclusive options to a classification of which options are dominated, a result that holds at every non-negative cost-effectiveness threshold.
Implementations
Excel
Classify a two-option comparison
Excel classifies the intervention as dominant, dominated or neither from named incremental values. Rounding the incremental values first keeps the equality branches meaningful when model outputs carry tiny numerical differences.
=IF(AND(IncrementalCost<=0,IncrementalEffect>=0,OR(IncrementalCost<0,IncrementalEffect>0)),"Dominant",IF(AND(IncrementalCost>=0,IncrementalEffect<=0,OR(IncrementalCost>0,IncrementalEffect<0)),"Dominated","No dominance"))
Assumptions
Inclusive treatment of ties
Equal cost with greater effect, or equal effect with lower cost, counts as dominance because the tied option can be discarded with no loss at any threshold. Identical cost and effect is not dominance. The tie case is ordinary dominance and is not called weak dominance, a term some texts use for extended dominance.
Consistent subtraction direction for dominance
Both differences take the intervention minus the comparator. The intervention is dominated when the rule holds for the comparator, that is with the signs of both differences reversed.
Expected values on a common basis
The classification uses expected costs and effects for the same population, perspective, time horizon and outcome measure. The share of probabilistic simulations in which an option dominates describes uncertainty and is not the decision rule.
Worked examples
Cheaper and more effective treatment
A new treatment costs £7,500 per patient and produces 4.8 QALYs, while current care costs £10,000 and produces 4.2 QALYs. Incremental cost is minus £2,500 and incremental effect is 0.6 QALYs, so the new treatment dominates and no threshold comparison is needed. Its incremental net monetary benefit is £2,500 plus 0.6 times the threshold, which is £14,500 at £20,000 per QALY and positive at every non-negative threshold. The figures are illustrative.
Delta_C = -2500; Delta_E = 0.6; DOM = 1
Equal cost with greater effect
An intervention costs the same as current care and produces 0.2 more QALYs. Incremental cost is zero, so a rule requiring both differences to be strict would leave the result unclassified; the inclusive rule classifies the intervention as dominant.
Delta_C = 0; Delta_E = 0.2; DOM = 1
Trade-off rather than dominance
An intervention costs £4,000 more and produces 0.30 more QALYs. Neither option dominates, so the comparison needs a threshold, through the ICER or net monetary benefit.
Delta_C = 4000; Delta_E = 0.30; DOM = 0
Common errors
Forgetting ties
Requiring both differences to be non-zero leaves equal-cost or equal-effect results unclassified, so an inferior tied option can remain in the analysis.
Reading a negative ICER as dominance
A negative ratio arises both when the intervention dominates and when it is dominated. Only the signs of Delta_C and Delta_E show which.
Sources
NICE manual on dominance
National Institute for Health and Care Excellence. NICE technology appraisal and highly specialised technologies guidance: the manual (PMG36). Published 31 January 2022, last updated 31 March 2026. Chapter 4 Economic evaluation, sections 4.2.16 (standard decision rules reflecting dominance and extended dominance) and 4.10.8 (dominated technologies, described as more costly and less effective than another technology, removed from the fully incremental analysis).
Cost-effectiveness plane quadrants
Black WC. The CE plane: a graphic representation of cost-effectiveness. Medical Decision Making. 1990;10(3):212-214.
Methods textbook on dominance
Drummond MF, Sculpher MJ, Claxton K, Stoddart GL, Torrance GW. Methods for the Economic Evaluation of Health Care Programmes. 4th ed. Oxford: Oxford University Press; 2015.
Canonical Identity
Stable URI · Machine-readable · Resolvable · CC BY 4.0