Description
Classify incremental cost/effect differences and calculate an ICER when effect difference is nonzero.
An incremental cost-effectiveness ratio divides the cost difference by the effect difference between alternatives. Its sign alone cannot distinguish a less costly, more effective option from a more costly, less effective one. Interpretation requires the effect direction, units and separate cost/effect signs, including zero differences.
Classify incremental cost/effect differences and calculate an ICER when effect difference is nonzero.
When to use this tool
Use ICER Dominance Quadrant Label when checking the stated cost-effectiveness-plane quadrant and ratio convention.
How to use the tool and how it works
- Enter incrementalCost, incrementalEffect. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read classification, icer, ratioDefined. Inspect ratioDefined before interpreting the associated values.
Compare incremental cost/effect signs, assuming larger effect is favorable, and distinguish dominance, tradeoffs, equal-cost/effect cases and no difference. Return cost/effect when effect!=0; otherwise return icer=0 with ratioDefined=false.1
Incremental evaluation considers both cost and effect differences. A negative ICER needs its quadrant to distinguish dominance from being dominated; no decision threshold is supplied here.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| incrementalCost | Incremental Cost | Required. Finite number. |
| incrementalEffect | Signed effect difference on a scale where larger is favorable. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| classification | Classification | Required. Text; maximum UTF-16 length 8192. |
| icer | Cost difference/effect difference; zero placeholder when ratioDefined=false. | Required. Finite number. |
| ratioDefined | False exactly when incrementalEffect=0; classification remains meaningful. | Required. Boolean. |
{
"input": {
"incrementalCost": -100,
"incrementalEffect": 0.2
},
"output": {
"classification": "dominant",
"icer": -500,
"ratioDefined": true
}
}Limitations and assumptions
- Negative ICERs can represent opposite dominance situations; use classification and ratioDefined rather than interpreting the ratio alone.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete incremental analysis with justified outcome direction, relevant comparators and uncertainty; seek qualified health-economic interpretation for actual decisions.
References
Similar or alternative tools
- Cost Effectiveness Plane Axis Unit Label
Label the cost and effect units used on a cost-effectiveness plane.
- Health Service Opportunity Cost Gap
Calculate valued benefit minus a supplied opportunity cost on a common basis.