Signature
Delta_C = C_new - C_comparator; Delta_E = E_new - E_comparator
| Inputs | Definition | Unit |
|---|---|---|
C_new | Total relevant cost of the new intervention | currency per defined population or person |
C_comparator | Total relevant cost of the comparator | the same currency and population basis as C_new |
E_new | Expected outcome for the new intervention | the selected outcome measure |
E_comparator | Expected outcome for the comparator | the same outcome measure as E_new |
Delta_C | Difference in cost between the new intervention and comparator | currency per defined population or person |
|---|---|---|
Delta_E | Difference in outcome between the new intervention and comparator | the selected outcome measure |
Function
Incremental comparison function
Maps the costs and effects of two healthcare alternatives to their incremental cost and incremental effect.
Try this function
Implementations
Excel
Calculate incremental results
Excel subtracts comparator values from new-intervention values using named ranges.
=NewCost-ComparatorCost; =NewEffect-ComparatorEffect
Assumptions
Relevant comparator
The comparator represents the healthcare choice actually available to the decision-maker.
Consistent analytical basis
Costs and effects for both alternatives use the same perspective, population, time horizon, price basis and discounting approach.
Comparable outcome measure
Effects for both alternatives are expressed using the same outcome definition and unit.
Worked examples
Current care compared with a new intervention
Current care costs £10,000 and produces 4.50 QALYs. The new intervention costs £14,000 and produces 4.80 QALYs. Incremental cost is £4,000 and incremental effect is 0.30 QALYs.
C_new = 14000; C_comparator = 10000; E_new = 4.80; E_comparator = 4.50; Delta_C = 4000; Delta_E = 0.30
Common errors
Using average instead of incremental results
Comparing separate average costs or outcomes does not show the change produced by choosing one alternative instead of another.
Sources
NICE health technology evaluations manual
National Institute for Health and Care Excellence. NICE technology appraisal and highly specialised technologies guidance: the manual (PMG36). Published 2022; last updated 31 March 2026. Chapter 4 Economic evaluation, table 4.1 (summary of the reference case) and section 4.2.16 (ICERs as expected additional total cost over expected additional QALYs).
Canonical Identity
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